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Definition: ASME (American Society of Mechanical Engineers) publishes technical codes and standards, in particular the Boiler and Pressure Vessel Code (BPVC). This defines requirements for the design, materials, manufacture and testing of pressure equipment.

Practical relevance: The ASME BPVC is recognised worldwide and forms the basis of many international plant projects. It contains specific requirements for materials, welding procedures and NDT.

Definition: ASTM (ASTM International, formerly the American Society for Testing and Materials) is a globally recognised standardisation organisation that develops technical standards for materials, testing methods and products. ASTM standards define requirements for chemical composition, mechanical properties and testing methods. They are particularly authoritative in the North American market.

Practical relevance: ASTM standards such as ASTM A516 (pressure vessel steel) or ASTM E1820 (fracture mechanics) are used internationally. They govern testing conditions, specimen geometries and acceptance criteria. In global projects, ASTM standards are frequently applied in parallel with EN or ISO standards.

Decision-making perspectives:

• Technical decision-makers: Ensuring internationally comparable material and testing criteria.
• Purchasing/project management: Contractually clear specification for export and US projects.
• Science: Comparability of test results worldwide.
• Insurance/law: Reference framework in international liability cases.

FAQ:

• Where are ASTM standards mainly applied?
• Primarily in the USA, but increasingly also in international industrial projects.

Definition: ASTM E1820 is a US testing standard for determining the fracture toughness of metallic materials. It describes procedures for determining parameters such as K_Ic, J-integral (J_Ic) and CTOD. The standard is central to the fracture mechanics assessment of components containing cracks.

Practical relevance: ASTM E1820 defines specimen geometries (CT, SENB), pre-cracking, loading rate and evaluation methods including R-curves. It is used in pressure equipment construction, in aviation and in the energy industry. Results feed into fitness-for-service analyses and service-life assessments.

Decision-making perspectives:

• Technical decision-makers: Assessment of critical crack sizes and safety margins.
• Purchasing/project management: Specification of fracture mechanics parameters in international projects.
• Science: Comparison with ISO 12135 and validation of crack growth models.
• Insurance/law: Verification of standard-compliant fracture toughness testing.

Typical testing or verification methods: CT and SENB specimens, J-R curves, CTOD determination.

FAQ:

• Which parameters are determined according to ASTM E1820?
• K_Ic, J_Ic and CTOD for assessing crack toughness.

Definition: Brazing procedure qualification testing is the qualifying examination of a brazing process to ensure reproducible joints that conform to standards. It serves to demonstrate that a defined brazing procedure achieves the required quality under specified parameters. Requirements are governed, among others, by DIN EN ISO 13585.

Practical relevance: The aspects assessed include braze seam quality, wetting, freedom from porosity, strength and tightness. Influencing factors are the temperature profile, filler material, flux and joint gap. The tests comprise visual inspection, metallographic sections, and tensile or shear tests. Procedure qualification is frequently a prerequisite for safety-relevant applications.

Decision-making perspectives:

• Technical decision-makers: Ensuring suitable process parameters and material combinations.
• Purchasing/project management: Requiring qualified procedures and documented test reports.
• Science: Analysis of diffusion zones and intermetallic phases.
• Insurance/law: Demonstration of standard-compliant procedure qualification in the event of a failure.

Typical testing or verification methods: Visual inspection, metallographic examination, tensile/shear test, leak test.

FAQ:

• Why is a brazing procedure qualification test required?
• It ensures that the selected brazing procedure reproducibly delivers the required quality under defined conditions.

Definition: Crack growth refers to the progressive propagation of an existing crack under mechanical or corrosive loading. It is described in fracture-mechanics terms using parameters such as the stress intensity factor ΔK or the J-integral. Under cyclic loading, the growth often follows the Paris law.

Practical relevance: Crack growth largely determines the remaining service life of cracked components. Influencing factors are stress amplitude, mean stress, material toughness, temperature and medium. Quantitative assessment is carried out using da/dN-ΔK curves. Applications are found in pressure equipment construction, structural steelwork and aviation.

Decision-making perspectives:

• Technical decision-makers: Definition of permissible crack sizes and inspection intervals.
• Purchasing/project management: Assessment of repair or replacement strategies based on remaining-service-life analyses.
• Science: Investigation of fatigue crack propagation and environmental influences.
• Insurance/law: Demonstration of whether a crack would have been controllable with proper monitoring.

Typical testing or verification methods: Fatigue crack growth test, fracture-mechanics assessment to DIN EN ISO 12108, non-destructive crack testing.

FAQ:

• What does the Paris law describe?
• It describes the relationship between the crack growth rate (da/dN) and the stress intensity factor range (ΔK) under cyclic loading.

Definition: Crack initiation refers to the formation of an initial microcrack in a material as a result of mechanical, thermal or chemical loading. It represents the first phase of a potential failure process. Typical causes are fatigue, stress corrosion cracking or local overload.

Practical relevance: Cracks frequently form at notches, inclusions, weld seam transitions or microstructural inhomogeneities. Influencing variables are stress amplitude, mean stress, surface roughness and corrosive media. Early detection is decisive for integrity assessment and remaining service life estimation in accordance with fracture mechanics approaches.

Decision-making perspectives:

• Technical decision-makers: Optimisation of design, surface quality and material selection.
• Purchasing/project management: Specification of suitable testing intervals and quality requirements.
• Science: Analysis of microstructural influencing factors and crack nucleation mechanisms.
• Insurance/law: Assessment of causes in cases of premature component failure.

Typical testing or verification methods: Non-destructive testing (MT, PT, UT), SEM fractography, metallography, fatigue tests.

FAQ:

• Where do cracks typically start?
• Frequently at notches, surface defects or microstructural inhomogeneities with local stress concentration.

Definition: Destructive testing methods are test methods in which a specimen is loaded until permanent deformation or fracture occurs in order to determine mechanical characteristic values. They provide quantitative information on strength, toughness and deformation behaviour. They are carried out in accordance with standardised methods.

Practical relevance: Typical methods are the tensile test (DIN EN ISO 6892-1), the notched-bar impact bending test (DIN EN ISO 148-1), the bending test or the compression test. Characteristic values such as yield strength, tensile strength, elongation at fracture or impact energy are evaluated. The results form the basis for material approvals, procedure qualifications and safety verifications.

Decision-making perspectives:

• Technical decision-makers: Assessment of mechanical performance under defined loading conditions.
• Purchasing/project management: Definition of binding minimum characteristic values in specifications.
• Science: Investigation of material behaviour up to failure.
• Insurance/law: Verification of specification-compliant properties in cases of damage.

Typical testing or verification methods: Tensile test, compression test, bending test, notched-bar impact bending test, hardness testing.

FAQ:

• Why are destructive testing methods necessary?
• Only they make it possible to directly determine mechanical limit values up to the failure of the material.

Definition: DIN (Deutsches Institut für Normung e. V.) is Germany’s national standardisation organisation. DIN standards define technical requirements, terms, testing methods and safety requirements. Many DIN standards are now harmonised as DIN EN or DIN EN ISO.

Practical relevance: DIN standards govern material properties, dimensions, tolerances and testing methods. They form the basis for contractual clarity, quality assurance and product safety in German-speaking countries. National particularities may exist in addition to European or international standards.

Decision-making perspectives:

• Technical decision-makers: Application of harmonised technical standards.
• Purchasing/project management: Legally sound specification in the German market.
• Science: Terminological and methodological consistency.
• Insurance/law: Benchmark for the recognised rules of engineering.

Definition: EN (European Standard) refers to harmonised standards adopted by CEN, CENELEC or ETSI. They serve to standardise technical requirements within the European single market. EN standards must be adopted by the member states.

Practical relevance: EN standards are frequently the basis for CE marking and conformity assessment. Examples include EN 1090 (steel construction) or EN ISO 15614 (welding procedure qualification). National standards with conflicting content are withdrawn.

Definition: EN 13134 is a European standard for the qualification of brazing procedures for load-bearing steel components. It describes requirements for specimen preparation, testing and ranges of validity. The aim is to demonstrate reproducible brazing quality.

Practical relevance: The standard requires mechanical testing, metallographic examinations and visual inspections. Ranges of validity relate to material groups, filler metals, temperature control and joint gap. It is relevant for safety-critical designs.

Decision-making perspectives:

• Technical decision-makers: Ensuring qualified brazing processes.
• Purchasing/project management: Requiring standard-compliant procedure qualification.
• Science: Analysis of diffusion zones and microstructural changes.
• Insurance/law: Documented qualification record.

Typical testing or verification methods: Tensile/shear test, micrograph examination, visual inspection.

FAQ:

• What does EN 13134 apply to?
• The qualification of brazing procedures on load-bearing steel components.

Definition: EN ISO 15614 is an international standard for the qualification of welding procedures by means of a procedure test (WPQR). It specifies the test conditions, specimen requirements and assessment criteria. The aim is to ensure reproducible welding quality.

Practical relevance: The tests comprise tensile, bend, notched-bar impact and hardness testing as well as macroscopic examinations. The qualified parameter range defines the scope of validity of the WPS. The standard is central to pressure equipment construction and steel construction.

Decision-making perspectives:

• Technical decision-makers: Safeguarding the mechanical characteristic values of the weld seam.
• Purchasing/project management: Binding proof of qualification prior to series production.
• Science: Investigation of heat-affected zones.
• Insurance/law: Standard-compliant process verification.

Typical testing or verification methods: Tensile test, notched-bar impact bending test, micrograph examination.

Definition: Failure analysis is the structured investigation of a technical component or plant failure in order to determine the primary and secondary causes of damage. It combines materials science, mechanical and operational analyses. The aim is the traceable reconstruction of the failure mechanism.

Practical relevance: The analysis covers fracture surfaces (fractography in the SEM), microstructural conditions (metallography), chemical composition (OES, EDX) as well as operating and load data. Typical mechanisms are fatigue, overload, corrosion or material mix-up. The assessment is carried out with reference to applicable standards, specifications and safety requirements.

Decision-making perspectives:

• Technical decision-makers: Derivation of design or process improvement measures.
• Purchasing/project management: Assessment of warranty claims or supplier responsibility.
• Science: Investigation of crack initiation, crack growth and microstructural influences.
• Insurance/law: Court-proof documentation of the cause of damage for the allocation of liability.

Typical testing or verification methods: SEM fractography, metallography, hardness testing, tensile test, non-destructive testing (NDT).

FAQ:

• What is the aim of a failure analysis?
• The unambiguous identification of the failure mechanism as a basis for prevention and liability assessment.

Definition: Hydrogen resistance describes the ability of a material to withstand the action of hydrogen without suffering damaging changes such as embrittlement, cracking or decarburisation. Hydrogen can diffuse into the metal and significantly affect its mechanical properties. The assessment is particularly relevant at elevated pressure and temperature.

Practical relevance: Typical damage mechanisms are hydrogen-induced cracking (HIC), stress corrosion cracking (SCC) and high temperature hydrogen attack (HTHA). The material composition, microstructure, hardness and operating parameters are assessed. Normative references include, among others, API 941 (Nelson curves) and NACE guidelines. Material selection is decisive for plants in the hydrogen economy and refinery technology.

Decision-making perspectives:

• Technical decision-makers: Selection of suitable alloys and definition of safe operating limits.
• Purchasing/project management: Specification of hydrogen-suitable materials in technical delivery conditions.
• Science: Investigation of diffusion mechanisms and interaction with the microstructure.
• Insurance/law: Demonstration of compliant material selection in the event of hydrogen-related damage.

Typical testing or verification methods: HIC testing, slow strain rate test (SSRT), metallography, hardness testing, fracture mechanics assessment.

FAQ:

• Why is hydrogen critical for many steels?
• Hydrogen can lead to embrittlement and delayed cracking, even at moderate stresses.

Definition: ISO (International Organization for Standardization) is a worldwide standardisation body for the development of internationally valid standards. ISO standards govern terminology, testing methods, management systems and technical requirements.

Practical relevance: Examples include ISO 9001 (quality management), ISO 4287 (roughness) or ISO 9712 (NDT personnel). ISO standards promote international comparability and market access.

Definition: ISO 25178 is an international series of standards for three-dimensional areal surface measurement. It defines 3D parameters such as Sa, Sz and Ssk. It is based on optical or tactile 3D measuring systems.

Practical relevance: The standard extends profile-based roughness analysis (ISO 4287) with areal parameters. It is relevant for tribological, functional and microstructured surfaces.

Definition: ISO 4287 defines roughness parameters for profile-based surface measurements. It describes parameters such as Ra, Rz or Rt and their mathematical determination. The standard is the basis of tactile roughness measurement.

Practical relevance: ISO 4287 specifies terms and calculation rules for profile parameters. In combination with ISO 16610, filters are applied. The standard is widely used in mechanical engineering and manufacturing.

Definition: KTA rules are safety-related codes and standards issued by the Nuclear Safety Standards Commission (Kerntechnischer Ausschuss) for German nuclear power plants. They give concrete form to statutory requirements for safety and quality.

Definition: Material specifications are binding technical stipulations regarding the chemical composition, mechanical properties, heat treatment and testing requirements of a material. They are based on standards or project-specific requirements. The aim is to define the material quality unambiguously.

Practical relevance: Specifications frequently refer to standards such as EN 10025, ASTM A516 or ISO material numbers. They define limit values for alloying elements, minimum strengths, impact energy, hardness ranges as well as the required test certificates (EN 10204). Unclear specifications increase the risk of material deviations and liability cases.

Decision-making perspectives:

• Technical decision-makers: Ensuring functionally and safety-appropriate material selection.
• Purchasing/project management: Contractually clear definition of scope of supply and quality verifications.
• Science: Assessment of material characteristic values in the context of new applications.
• Insurance/law: Basis for assessing contractual and quality deviations.

Typical testing or verification methods: Spectral analysis, mechanical materials testing, test certificates in accordance with EN 10204, comparison with standard tables.

FAQ:

• Why are precise material specifications important?
• They avoid scope for interpretation and ensure that materials meet the required technical properties.

Definition: Materials analysis is the systematic investigation of the chemical composition, microstructure and mechanical properties of a material. It serves to verify specification conformity as well as to determine the causes of failure. The analysis combines spectroscopic, microscopic and mechanical testing methods.

Practical relevance: Typical methods are spectral analysis (OES, XRF), metallography, scanning electron microscopy (SEM/EDX), hardness testing as well as tensile or impact testing. Alloying elements are assessed in accordance with the material standard (e.g. EN 10025, ASTM), grain size according to DIN EN ISO 643, phase fractions and characteristic values such as strength or toughness. The results are central to quality control, PMI and failure investigation.

Decision-making perspectives:

• Technical decision-makers: Verification of material conditions, heat treatment and microstructure quality.
• Purchasing/project management: Comparison with technical delivery conditions and test certificates (EN 10204).
• Science: Correlation of microstructure, composition and mechanical behaviour.
• Insurance/law: Court-proof evidence of material deviations or failure mechanisms.

Typical testing or verification methods: OES, XRF, SEM/EDX, metallography, hardness testing, tensile test, notched bar impact test.

FAQ:

• When is a materials analysis required?
• In the case of quality deviations, failures or to verify the material specification at incoming goods inspection.

Definition: Materials testing comprises all test methods for determining the mechanical, physical and chemical properties of a material. It serves to establish standardised characteristic values and to verify conformity with specifications. Tests can be carried out destructively or non-destructively.

Practical relevance: Typical mechanical tests are the tensile test (DIN EN ISO 6892-1), hardness testing (ISO 6506/6507/6508) and the notched-bar impact test (ISO 148-1). These are complemented by corrosion tests, microstructure analyses and spectral analyses. The results form the basis for material releases, quality assurance and safety assessments.

Decision-making perspectives:

• Technical decision-makers: Assessment of strength, toughness and suitability for defined operating conditions.
• Purchasing/project management: Requirement for standard-compliant test certificates (e.g. EN 10204 3.1) and acceptance criteria.
• Science: Analysis of relationships between microstructure and characteristic values.
• Insurance/law: Verification of specification-compliant properties in disputes or damage cases.

Typical testing or verification methods: Tensile test, hardness testing, notched-bar impact test, metallography, spectral analysis, NDT.

FAQ:

• What is the difference between destructive and non-destructive materials testing?
• Destructive tests determine characteristic values up to failure, whereas non-destructive methods test components without causing damage.

Definition: Measurement methods are systematic procedures for the quantitative determination of physical, geometric or chemical quantities. They serve to objectively record actual values and to compare them with specified target requirements. They are based on defined measurement principles, calibration and known measurement uncertainty.

Practical relevance: In materials testing and quality assurance, tactile, optical, electrical and non-destructive measurement methods (NDT) are used. Selection criteria are measuring range, accuracy, resolution, reproducibility and standard conformity (e.g. ISO 10360 for CMMs, ISO 6507 for hardness testing). A documented measurement uncertainty analysis is required in particular in regulated industries.

Decision-making perspectives:

• Technical decision-makers: Selection of suitable measurement principles for function- and safety-critical characteristics.
• Purchasing/project management: Definition of testable specifications and acceptance criteria.
• Science: Validation of measurement methods, uncertainty budget and comparative studies.
• Insurance/law: Traceability and verifiability of measurement results as evidence.

Typical testing or verification methods: Coordinate measuring technology, roughness measurement, hardness testing, spectroscopic analysis, ultrasonic testing.

FAQ:

• Why is measurement uncertainty decisive?
• It determines whether a measured value lies within or outside a tolerance with sufficient certainty.

Metallography

Definition: Metallography is the preparative and microscopic examination of the microstructure of metallic materials. The aim is to analyse grain size, phase distribution, precipitates and defects. It forms the basis for assessing material conditions and failure mechanisms.

Practical relevance: The procedure comprises sampling, mounting, grinding, polishing and etching, as well as examination using a light microscope or scanning electron microscope (SEM). Items assessed include grain size according to DIN EN ISO 643, weld seam microstructure, decarburisation and crack initiation. Metallography is central to failure analysis, heat treatment testing and quality assurance.

Decision-making perspectives:

• Technical decision-makers: Assessment of microstructure quality, heat treatment and manufacturing parameters.
• Purchasing/project management: Verification of specification-compliant material conditions.
• Science: Microstructure analysis and correlation with mechanical properties.
• Insurance/law: Microscopic verification of material-related failure causes.

Typical testing or verification methods: Specimen preparation, microstructure etching, light microscopy, SEM, EBSD, hardness testing.

FAQ:

• Why is etching necessary in metallography?
• Etching makes microstructural constituents and grain boundaries visible that are not discernible in the polished condition.

Definition: Molten salts are melted inorganic salts used as heat-transfer, reaction or heat-treatment media at elevated temperatures. Typical systems are based on nitrates, chlorides or carbonates. They are characterised by high heat capacity and thermal stability.

Practical relevance: Applications are found in heat treatment, solar thermal energy or the chemical process industry. Molten salts can be highly corrosive, particularly towards unalloyed or low-alloy steels. Temperature range, oxygen content, impurities and material resistance are assessed. Suitable materials or coatings are decisive for plant integrity.

Decision-making perspectives:

• Technical decision-makers: Selection of corrosion-resistant materials and monitoring of the salt chemistry.
• Purchasing/project management: Specification of suitable material grades and testing requirements.
• Science: Investigation of high-temperature corrosion and diffusion processes.
• Insurance/law: Assessment of corrosion damage and compliance with technical codes and standards.

Typical testing or verification methods: High-temperature corrosion tests, metallography, weight-loss measurement, materials analysis.

FAQ:

• Why are molten salts corrosive?
• Molten salts can destabilise protective layers and promote electrochemical reactions at high temperatures.

Definition: A nanoindenter is a measuring system for instrumented indentation testing in the nanometre to micrometre range. The force-displacement curve of an indenter is continuously recorded in order to determine mechanical characteristic values such as nanohardness and elastic modulus. The method is based on evaluation according to Oliver-Pharr.

Practical relevance: Nanoindentation is particularly suitable for thin films, coatings, microstructures or individual microstructural constituents. Typical test loads are in the mN range and indentation depths in the nm range. Hardness (HIT), reduced elastic modulus (Er) as well as creep and relaxation behaviour are assessed. Surface preparation and roughness considerably influence the measurement accuracy.

Decision-making perspectives:

• Technical decision-makers: Characterisation of coatings and graded materials.
• Purchasing/project management: Verification of specified coating properties for high-performance components.
• Science: Investigation of local mechanical properties and microstructural heterogeneity.
• Insurance/law: Documentation of mechanical properties in the event of coating failure.

Typical testing or verification methods: Instrumented indentation testing, force-displacement analysis, evaluation according to ISO 14577.

FAQ:

• What is the advantage of a nanoindenter?
• It enables the determination of local mechanical properties of very small volumes or thin films.

Definition: Non-destructive testing (NDT) comprises testing methods for detecting defects or inhomogeneities in materials and components without damaging them. The aim is to assess integrity during manufacture or operation. Qualification requirements for personnel are governed by DIN EN ISO 9712.

Practical relevance: Typical methods are ultrasonic testing (UT), radiography (RT), magnetic particle testing (MT), penetrant testing (PT) and visual testing (VT). They identify cracks, pores, inclusions or wall thickness losses. NDT is central to pressure equipment, welded structures and safety-relevant plants.

Decision-making perspectives:

• Technical decision-makers: Ensuring component integrity and early defect detection.
• Purchasing/project management: Definition of inspection classes, scopes and documentation requirements.
• Science: Assessment of detection limits and comparison of different testing methods.
• Insurance/law: Evidence of proper testing in the context of safety and liability matters.

Typical testing or verification methods: UT, RT, MT, PT, VT, eddy current testing (ET), wall thickness measurement.

FAQ:

• When is NDT preferable to destructive testing?
• When components have to be tested in their installed state or safety-relevant components have to be assessed without damage.

Definition: Optical emission spectroscopy (OES) is an analytical method for the quantitative determination of the chemical composition of metallic materials. Through electrical excitation (spark or arc discharge), elements emit characteristic spectral lines that are detected and evaluated. The method is particularly well established for alloy analyses.

Practical relevance: OES enables the rapid analysis of major and trace elements in steels and aluminium, nickel or copper alloys. Detection limits range from the ppm to the weight per cent range, depending on the element and instrument type. The method is used for incoming goods inspection, melt analyses and positive material identification (PMI). Representative sample preparation is decisive for valid results.

Decision-making perspectives:

• Technical decision-makers: Ensuring specification-compliant alloys and avoiding material mix-ups.
• Purchasing/project management: Binding specification of chemical limit values in accordance with material standards.
• Science: Validation of analytical accuracy and comparison with reference methods (e.g. ICP-OES).
• Insurance/law: Documented material verification in cases of damage or liability.

Typical testing or verification methods: Spark OES, calibration with reference samples, comparative analysis, PMI testing.

FAQ:

• What is OES mainly used for?
• For the rapid and quantitative determination of the chemical composition of metallic materials.

Definition: On-site investigations are technical testing and analysis measures carried out directly on installed components or plant equipment. They enable the assessment of condition, integrity and damage mechanisms without complete dismantling. Mobile testing devices and replica techniques are frequently used.

Practical relevance: Typical methods are ultrasonic testing (UT), visual inspection (VT), mobile hardness testing, PMI and metallographic replicas. On-site investigations minimise downtime and support fitness-for-service or RBI assessments. Documentation and traceability are decisive for later assessments.

Decision-making perspectives:

• Technical decision-makers: Rapid condition assessment and a basis for deciding on continued operation or repair.
• Purchasing/project management: Reduction of downtime costs and targeted maintenance planning.
• Science: Comparison of in-situ and laboratory results in terms of significance.
• Insurance/law: Documented evidence of condition during ongoing operation.

Typical testing or verification methods: UT, VT, MT/PT, mobile hardness testing, PMI, replica metallography.

FAQ:

• What advantages do on-site investigations offer?
• They enable a rapid, economical condition assessment without extensive dismantling or transport.

Definition: Optical measurement methods are non-contact measurement techniques for capturing the geometric, topographic or deformation properties of a workpiece. They use light as the carrier of information, e.g. lasers, white light or camera systems. The aim is precise and rapid data acquisition without mechanical contact.

Practical relevance: The methods include 3D laser scanning, fringe projection, white-light interferometry and digital image correlation (DIC). They are suitable for sensitive surfaces, complex free-form geometries and dynamic measurement tasks. Dimensional deviations, surface parameters or strains are evaluated. Influencing factors are surface reflection, calibration and ambient conditions.

Decision-making perspectives:

• Technical decision-makers: Selection of suitable systems for rapid inline or laboratory testing.
• Purchasing/project management: Assessment of investment costs, accuracy and integration capability.
• Science: Analysis of measurement uncertainties and comparison with tactile methods.
• Insurance/law: Documented geometry verification without component damage.

Typical testing or verification methods: 3D scan, fringe projection, white-light interferometry, digital image correlation.

FAQ:

• When are optical measurement methods advantageous?
• With sensitive surfaces, complex geometries or when rapid, non-contact measurement is required.

Definition: Orientation and location testing is the metrological determination of deviations of a geometrical feature with regard to its orientation or position relative to defined datum features. It assesses location tolerances such as parallelism, perpendicularity, angularity or position. The basis is geometrical product specifications according to DIN EN ISO 1101.

Practical relevance: Location deviations affect the assemblability, tightness and functional reliability of components. The assessment is carried out by comparing the measured geometry with defined tolerance zones, referenced to datum surfaces or axes. Measuring instruments are coordinate measuring machines (CMM), optical 3D scanners or special gauges. Measurement uncertainty and the correct selection of datums are decisive.

Decision-making perspectives:

• Technical decision-makers: Ensuring function-critical alignments and minimising wear or vibrations.
• Purchasing/project management: Unambiguous definition of datum and tolerance specifications in drawings.
• Science: Analysis of tolerance chains and the influence of manufacturing variation.
• Insurance/law: Proof of position or alignment errors in the event of complaints.

Typical testing or verification methods: CMM measurement, optical 3D metrology, evaluation according to the GPS framework of standards.

FAQ:

• What is the difference between form tolerance and location tolerance?
• Form tolerances concern the shape of a feature, location tolerances its orientation or position relative to a datum.

Definition: The PED 2014/68/EU is the European Pressure Equipment Directive governing the design, manufacture and conformity assessment of pressure equipment. It is mandatory for placing products on the EU single market.

Definition: A peer review of manufacturing processes is the independent technical assessment of production workflows, process parameters and quality records by qualified external experts. The aim is the objective evaluation of process stability, standards conformity and risk potential. The procedure complements internal audits with a neutral perspective.

Practical relevance: The assessment covers process capability (Cp, Cpk), test planning, validation reports, traceability and compliance with relevant standards (e.g. ISO 9001, IATF 16949). Weaknesses in documentation, parameter settings or test equipment management are systematically identified. The peer review serves to minimise risk before series start-up, certification or investment decisions.

Decision-making perspectives:

• Technical decision-makers: External validation of critical process steps and quality metrics.
• Purchasing/project management: Objective basis for supplier approvals or investment decisions.
• Science: Method-critical evaluation of statistical analyses and process models.
• Insurance/law: Documented evidence of technical due diligence and risk assessment.

Typical testing or verification methods: Document audit, on-site inspection, process capability analysis, sample testing.

FAQ:

• When does a peer review of manufacturing processes make sense?
• Before series start, in the event of quality problems or for the independent evaluation of complex production processes.

Definition: Positive Material Identification (PMI) is the analytical verification of the chemical composition of a material for unambiguous material assignment. The aim is to prevent material mix-ups in safety-relevant applications. The test is carried out with minimal destruction directly on the component.

Practical relevance: PMI is used in particular in plant, pipeline and pressure equipment construction. Typical methods are mobile X-ray fluorescence analysis (XRF) or optical emission spectroscopy (OES). The alloying elements are checked in accordance with the material specification (e.g. EN 10025, ASTM). Incorrect assignments can lead to corrosion or HTHA damage.

Decision-making perspectives:

• Technical decision-makers: Ensuring correct material use in plants critical to media or temperature.
• Purchasing/project management: Requirement for documented PMI test reports at goods receipt or installation.
• Science: Assessment of the analytical accuracy and detection limits of the methods used.
• Insurance/law: Documented material verification to safeguard against liability.

Typical testing or verification methods: Mobile XRF, spark OES, comparison with test certificates in accordance with EN 10204.

FAQ:

• Why is PMI important in plant construction?
• Material mix-ups can lead to serious corrosion or safety problems and must be ruled out.

Definition: Probabilistic safety analyses (PSA) are quantitative methods for assessing the risks of technical systems on the basis of probability models. They analyse the probability of occurrence and the consequences of potential malfunctions or damage events. The aim is the systematic determination and reduction of risk levels.

Practical relevance: PSA are used in particular in nuclear facilities, the process industry, aviation and energy supply. Methods include fault tree analysis (FTA), event tree analysis (ETA) and Monte Carlo simulations. Failure probabilities, frequencies of damage scenarios and risk metrics are assessed. Regulatory requirements arise, among other things, from international safety guidelines and industry-specific regulations.

Decision-making perspectives:

• Technical decision-makers: Identification of critical components and prioritisation of technical measures.
• Purchasing/project management: Risk-based investment decisions and resource planning.
• Science: Model validation, sensitivity analyses and statistical uncertainty assessment.
• Insurance/law: Quantitative proof of systematic risk assessment and duty of care.

Typical testing or verification methods: Fault tree analysis (FTA), event tree analysis (ETA), Monte Carlo simulation, sensitivity analysis.

FAQ:

• What is the advantage of probabilistic over deterministic analyses?
• They take probabilities and uncertainties into account and enable a quantitative risk assessment.

Definition: Procedure qualification tests are qualifying tests to confirm that a technical process reproducibly delivers the required properties under defined conditions. They serve to demonstrate process capability and process stability. The requirements arise from standards or project-specific specifications.

Practical relevance: Examples include welding procedure qualification tests (DIN EN ISO 15614), brazing/soldering procedure qualification tests or qualifications of additive manufacturing processes. Mechanical characteristic values, microstructure, dimensional accuracy or leak-tightness are assessed. The documented range of validity defines the permissible parameters and material groups.

Decision-making perspectives:

• Technical decision-makers: Ensuring that processes achieve the required quality under series production conditions.
• Purchasing/project management: Requiring valid qualification certificates before awarding a contract.
• Science: Analysis of process parameters and their influence on material properties.
• Insurance/law: Proof of standard-compliant process qualification in the event of damage.

Typical testing or verification methods: Mechanical tests, metallographic examinations, NDT, documentation in the test report.

FAQ:

• What is the purpose of a procedure qualification test?
• The formal proof that a defined procedure reproducibly achieves the required quality under specified parameters.

Definition: Process analysis is the systematic examination of technical production or testing processes to assess their performance, stability and reproducibility. It identifies influencing variables, weak points and optimisation potential. It is based on technical metrics and statistical evaluations.

Practical relevance: The aspects assessed include process parameters, process capability (Cp, Cpk), reject rates, tolerance compliance and the status of test equipment. Methods such as FMEA, SPC and cause-and-effect analysis support structured assessment. Process analysis is central to series production launch, quality deviations or process changes.

Decision-making perspectives:

• Technical decision-makers: Optimisation of critical parameters and safeguarding of stable series processes.
• Purchasing/project management: Assessment of supplier processes and investment requirements.
• Science: Modelling of process chains and statistical validation.
• Insurance/law: Evidence of proper process monitoring in quality disputes.

Typical testing or verification methods: Process capability analysis, SPC evaluation, auditing, measurement system analysis (MSA).

FAQ:

• What is the difference between process analysis and production monitoring?
• Process analysis assesses processes in a fundamental and optimising way, whereas production monitoring ensures ongoing control.

Definition: Process development is the structured process of designing, testing and optimising technical manufacturing or testing methods. The aim is to achieve defined quality, performance and economic efficiency requirements. It comprises experimental investigations, parameter studies and validation steps.

Practical relevance: Typical steps are laboratory trials, pilot applications, scaling up to series production conditions and process validation. Process stability, reproducibility, characteristic values (e.g. strength, hardness, dimensional accuracy) and economic efficiency are assessed. Methods such as Design of Experiments (DoE) or statistical experimental design support the optimisation.

Decision-making perspectives:

• Technical decision-makers: Development of robust processes with defined tolerance and quality windows.
• Purchasing/project management: Assessment of investment requirements, time-to-market and scalability.
• Science: Investigation of cause-and-effect relationships between process parameters and material properties.
• Insurance/law: Documentation of validated processes as evidence of technical due diligence.

Typical testing or verification methods: Pilot trials, process capability analysis, mechanical materials testing, statistical experimental design (DoE).

FAQ:

• When is structured process development necessary?
• For new products, materials or changed requirements that existing processes do not meet.

Definition: Risk-Based Inspection (RBI) is a risk-based methodology for planning and prioritising inspection measures in technical plants. It combines the probability of occurrence of damage with its potential consequences. The international foundations are API 580 (guideline) and API 581 (calculation methodology).

Practical relevance: RBI is used in particular in the process, oil and gas industries. Corrosion mechanisms, material condition, operating parameters and damage consequences are assessed. The result is a risk-based classification from which inspection intervals, testing methods (e.g. UT, RT) and measures are derived. The aim is to optimise safety, availability and maintenance costs.

Decision-making perspectives:

• Technical decision-makers: Focus on risk-critical components and efficient resource allocation.
• Purchasing/project management: Economic planning of testing and maintenance budgets.
• Science: Modelling of failure probabilities and sensitivity analyses.
• Insurance/law: Demonstration of systematic risk assessment and compliance with technical duties of care.

Typical testing or verification methods: Wall thickness measurement (UT), visual inspection, corrosion monitoring, probabilistic risk analysis.

FAQ:

• What is the advantage of RBI compared to fixed inspection intervals?
• Inspection resources are deployed in a risk-oriented manner, thereby increasing safety and reducing unnecessary inspections.

Definition: RCC-M is a French code for the design and manufacture of mechanical components in nuclear power plants. It defines material requirements, welding qualification and testing methods.

Definition: Rockwell hardness testing is a static indentation method in which the hardness is determined from the permanent indentation depth of an indenter under a defined preliminary and main load. The method is governed by DIN EN ISO 6508. Results are given in scales such as HRC or HRB.

Practical relevance: Rockwell testing is characterised by short testing times and direct readability. Different indenters (diamond cone or steel ball) allow various material ranges to be tested. It is frequently used to check hardened steels (HRC) or softer metals (HRB). Surface condition and specimen thickness influence the accuracy.

Decision-making perspectives:

• Technical decision-makers: Rapid checking of heat treatment results in series production.
• Purchasing/project management: Specification of required Rockwell hardness ranges in material requirements.
• Science: Comparison with Vickers or Brinell hardness values and conversion tables.
• Insurance/law: Documented hardness verification in the event of material deviations.

Typical testing or verification methods: Rockwell testing machine, calibration with reference hardness blocks, conversion tables in accordance with ISO standards.

FAQ:

• When is the HRC scale used?
• The HRC scale is mainly used for hardened or high-strength steels.

Definition: Roundness testing is the metrological determination of the deviation of a real circular cross-section from the ideal circular form. It assesses compliance with roundness tolerances in accordance with DIN EN ISO 12181. The analysis is carried out by recording profile points and comparing them with a reference geometry.

Practical relevance: Roundness deviations affect the running behaviour, tightness and wear of rotating components such as shafts, bearings or sealing surfaces. The maximum radial deviation within a defined tolerance zone is assessed. Measurements are carried out with roundness measuring instruments or high-precision coordinate measuring machines. Temperature, clamping condition and storage can influence the measurement result.

Decision-making perspectives:

• Technical decision-makers: Ensuring low-vibration rotation and minimal bearing load.
• Purchasing/project management: Clear definition of permissible roundness tolerances in drawings.
• Science: Analysis of manufacturing deviations and form parameters.
• Insurance/law: Verification of geometric deviations in the event of malfunctions.

Typical testing or verification methods: Roundness measuring instrument with rotary table, polar or Cartesian evaluation, comparison with GPS tolerance specifications.

FAQ:

• What is the difference between roundness and cylindricity?
• Roundness refers to a single cross-section, cylindricity to the entire lateral surface of a cylinder.

Definition: Special tests are individually developed or adapted testing methods for clarifying specific technical questions that are not sufficiently covered by standardised normative tests. They frequently combine several analysis and testing methods. The aim is a robust, problem-oriented assessment.

Practical relevance: Fields of application include complex failure cases, novel materials, atypical loading scenarios or special regulatory requirements. Special tests can comprise modified mechanical tests, combined environmental stresses or special specimen geometries. A traceable documentation of the test set-up, boundary conditions and measurement uncertainty is essential.

Decision-making perspectives:

• Technical decision-makers: Clarification of specific failure mechanisms or suitability verifications beyond standardised tests.
• Purchasing/project management: Definition of individual acceptance criteria for innovative products.
• Science: Development of validatable test designs and comparison with reference methods.
• Insurance/law: Court-proof documentation in exceptional failure or dispute cases.

Typical testing or verification methods: Combined climatic and load tests, modified fatigue tests, special corrosion or media tests.

FAQ:

• When are special tests required?
• When normative standard tests do not sufficiently represent the specific technical question.

Definition: Spectral analysis is an analytical method for determining the chemical composition of a material on the basis of characteristic emission or absorption spectra. It uses the element-specific spectral lines for qualitative and quantitative analysis. In materials engineering, it is used to determine alloying and trace elements.

Practical relevance: Typical methods are optical emission spectroscopy (OES), X-ray fluorescence analysis (XRF) or ICP-OES. Detection limits and accuracy depend on the method and the sample preparation. Applications include incoming goods inspections, PMI testing and failure analyses. Results are compared with normative material specifications.

Decision-making perspectives:

• Technical decision-makers: Ensuring the correct material composition in safety-relevant components.
• Purchasing/project management: Verification of supplier assurances in accordance with material standards.
• Science: Validation of analytical accuracy and comparison of different spectrometry methods.
• Insurance/law: Documented proof of material deviations in liability cases.

Typical testing or verification methods: OES, XRF, ICP-OES, comparison with reference materials.

FAQ:

• What is the difference between OES and XRF?
• OES uses emission lines after spark excitation, whereas XRF measures fluorescent X-rays without removing material.

Definition: The standard tests according to Streicher and Strauss are standardised corrosion testing methods for assessing the resistance of stainless steels to intergranular corrosion. They serve to verify whether sensitisation due to chromium carbide precipitation is present. The methods are governed by DIN EN ISO 3651.

Practical relevance: The Strauss test (copper sulphate-sulphuric acid test) and the Streicher test (ferric sulphate-sulphuric acid test) examine the susceptibility to corrosion along grain boundaries. Mass loss, crack formation or microstructural attack are assessed after a defined exposure time. The tests are relevant after welding or heat treatment processes of austenitic steels.

Decision-making perspectives:

• Technical decision-makers: Ensuring the intergranular corrosion resistance of welded components.
• Purchasing/project management: Requiring standard-compliant test certificates for corrosion-critical applications.
• Science: Analysis of sensitisation mechanisms and carbide precipitation.
• Insurance/law: Verification of specification-compliant corrosion resistance in cases of damage.

Typical testing or verification methods: Strauss test, Streicher test, metallographic microstructure examination after exposure.

FAQ:

• When are Streicher or Strauss tests carried out?
• After welding or heat treatment processes to test for susceptibility to intergranular corrosion.

Definition: The stylus profilometry method is a tactile measurement technique for determining surface roughness, in which a diamond stylus tip traces the surface along a defined measurement length. The height profile is recorded and evaluated mathematically. The normative bases are DIN EN ISO 4287 and ISO 16610.

Practical relevance: Parameters such as Ra, Rz or Rt are calculated from the profile. The choice of cut-off wavelength (λc), filter type and measurement length significantly influences the result. The method is well established for the quality control of sealing faces, bearing locations and tribologically loaded components. The stylus tip radius and force must be matched to the surface.

Decision-making perspectives:

• Technical decision-makers: Ensuring function-appropriate roughness parameters for friction and sealing systems.
• Purchasing/project management: Clear specification of roughness parameters and measurement conditions in drawings.
• Science: Analysis of filtering methods and comparison with optical 3D topography.
• Insurance/law: Traceable verification of surface requirements in the event of functional deviations.

Typical testing or verification methods: Profile acquisition with a stylus instrument, filtering in accordance with ISO 16610, parameter evaluation (Ra, Rz).

FAQ:

• Why is the choice of filter important in the stylus profilometry method?
• It separates roughness from waviness and significantly influences the calculated parameters.

Definition: Surface measurement is the quantitative recording of roughness, waviness and three-dimensional topography of a technical surface. It serves to evaluate functional properties such as friction, tightness or coating adhesion. Normative bases include DIN EN ISO 4287 and ISO 25178.

Practical relevance: Characteristic values such as Ra, Rz or Sa describe height deviations in the micro and macro range. Measurement methods are tactile stylus instruments or optical 3D profilometers. Filter settings (e.g. in accordance with ISO 16610) influence the evaluation. Surface quality is decisive for tribological systems, sealing surfaces and joined connections.

Decision-making perspectives:

• Technical decision-makers: Ensuring functionally appropriate surfaces for wear and tightness requirements.
• Purchasing/project management: Definition of unambiguous roughness characteristic values in drawings and specifications.
• Science: Analysis of topography structures and their influence on friction and wetting.
• Insurance/law: Verification of surface deviations in functional or liability matters.

Typical testing or verification methods: Stylus profiling method, optical white-light interferometry, 3D laser scanning, profile analysis.

FAQ:

• What is the difference between roughness and waviness?
• Roughness describes fine microstructures, waviness larger periodic deviations of the surface.

Definition: Tactile measurement methods are contact-based measuring techniques in which a mechanical stylus traces or makes point contact with the surface of a workpiece. The position data acquired serve to determine geometric or topographical characteristics. They are widely used in industrial metrology.

Practical relevance: Applications include coordinate measuring machines (CMMs), stylus instruments for roughness measurement and form measuring instruments. Their advantages are high accuracy and robust measurement results under defined boundary conditions. Influencing factors are the probing force, the stylus tip radius and the surface condition. Normative bases are found, among others, in ISO 10360 and ISO 4287.

Decision-making perspectives:

• Technical decision-makers: Selection of suitable measurement strategies for function-critical geometries.
• Purchasing/project management: Weighing up tactile against optical metrology in terms of accuracy and component suitability.
• Science: Analysis of measurement uncertainty and comparison with non-contact methods.
• Insurance/law: Reliable geometry verification in quality or liability matters.

Typical testing or verification methods: CMM point measurement, stylus profiling, roundness and form measurement.

FAQ:

• When are tactile measurement methods particularly suitable?
• For high-precision measurement tasks with defined surfaces and when maximum measurement accuracy is required.

Definition: Technical due diligence is the systematic assessment of the technical condition, safety and regulatory conformity of plants, properties or production systems in the context of transactions. It serves to identify technical risks, maintenance backlogs and investment requirements. The analysis is carried out independently and is supported by documentation.

Practical relevance: The assessment covers plant integrity, remaining service life, maintenance history, spare parts availability and compliance with statutory requirements (e.g. BetrSichV, Pressure Equipment Directive 2014/68/EU). Methods include document audits, on-site inspections, material analyses and RBI assessments. The results influence the purchase price, warranties and risk provisions.

Decision-making perspectives:

• Technical decision-makers: Assessment of technical weak points and modernisation requirements.
• Purchasing/project management: Investment decision based on quantified CAPEX/OPEX risks.
• Science: Methodical evaluation of condition and service life models.
• Insurance/law: Documented evidence of risk and compliance review for liability questions.

Typical testing or verification methods: Document review, NDT (UT, VT), materials analysis, remaining service life analysis, RBI.

FAQ:

• When is a technical due diligence required?
• For company acquisitions, investments or refinancing to assess technical risks and obligations.

Definition: Transmission electron microscopy (TEM) is a high-resolution analysis method in which an electron beam passes through an extremely thin specimen. Interactions generate imaging and diffraction information with atomic or nanometric resolution. The method allows the investigation of crystal structure and defects.

Practical relevance: TEM is used to analyse precipitates, dislocations, phase boundaries and nanostructures. Complementary techniques such as electron diffraction (SAED) or STEM-EDX enable detailed structural and chemical analyses. Specimen preparation (e.g. FIB lamellae) is demanding and requires great care.

Decision-making perspectives:

• Technical decision-makers: Investigation of nanoscale defects or failure mechanisms in high-performance materials.
• Purchasing/project management: Commissioning specialised analyses for complex development or failure questions.
• Science: Analysis of atomic lattice structures, phase identification and defect characterisation.
• Insurance/law: High-resolution verification of material defects in disputed damage cases.

Typical testing or verification methods: TEM imaging, SAED diffraction, STEM-EDX analysis, FIB specimen preparation.

FAQ:

• What is the advantage of TEM compared to SEM?
• TEM achieves significantly higher resolutions and enables the analysis of crystal structures at the atomic level.

Definition: The tensile test is a destructive mechanical testing method for determining the deformation and strength behaviour of a material under uniaxial tensile loading. A standardised specimen is elongated until fracture while force and change in length are recorded continuously. For metallic materials, the method is governed by DIN EN ISO 6892-1.

Practical relevance: The characteristic values determined include yield strength (ReH or Rp0.2), tensile strength (Rm), elongation at fracture (A) and modulus of elasticity (E). The stress-strain curve provides information on elastic and plastic behaviour. The tensile test is the basis for material approvals, procedure qualifications (e.g. welding procedure qualification) and static component design.

Decision-making perspectives:

• Technical decision-makers: Assessment of the load-bearing capacity and safety margins of a material.
• Purchasing/project management: Definition of minimum characteristic values in material specifications.
• Science: Analysis of the plastic deformation behaviour and material model.
• Insurance/law: Verification of mechanical properties in cases of failure or liability.

Typical testing or verification methods: Tensile test on a universal testing machine, extensometer measurement, evaluation of the stress-strain curve.

FAQ:

• Why is the tensile test so important?
• It provides key mechanical characteristic values that are required for design, standard compliance and safety assessment.

Definition: Test equipment management refers to the systematic administration, monitoring and calibration of measuring and testing equipment within a quality management system. The aim is to ensure correct and traceable measurement results. Requirements arise, among others, from ISO 9001 and DIN EN ISO/IEC 17025.

Practical relevance: Among the items recorded and assessed are test equipment identification, calibration status, intervals, relevant measurement uncertainties and areas of use. Complete and up-to-date documentation makes it possible to avoid the use of unsuitable or overdue measuring instruments. Faulty test equipment can lead to systematic wrong decisions, complaints or liability cases.

Decision-making perspectives:

• Technical decision-makers: Ensuring reliable and traceable measurement data in production and testing.
• Purchasing/project management: Selection of suitable test equipment as well as competent calibration and testing service providers.
• Science: Assessment of measurement uncertainties, comparative measurements and measurement methods.
• Insurance/law: Proof of standard-compliant test equipment monitoring in the context of liability and damage cases.

Typical testing or verification methods: Calibration, test equipment monitoring systems, auditing, measurement systems analysis (MSA).

FAQ:

• Why is test equipment management legally relevant?
• It documents compliance with duties of care and the validity of quality-relevant measurements.

Definition: VDI 3822 is a guideline for the structured execution of failure analyses of technical products. It describes the procedure, documentation and root-cause assessment. The aim is a reproducible and traceable analysis.

Practical relevance: The guideline defines systematic steps from securing the evidence through analysis to the report. It increases the quality and comparability of failure assessment reports.

Definition: Vickers hardness testing is a static indentation method for determining the hardness of metallic materials using a pyramid-shaped diamond tip. The hardness is calculated from the test force and the indentation diagonal. The method is standardised in DIN EN ISO 6507.

Practical relevance: The Vickers method can be used universally – from soft metals to high-hardness steels – and is also suitable for thin coatings or surface layers. Results are given as HV values together with the test force and dwell time (e.g. HV10). Precise specimen preparation and optical evaluation are decisive for reproducible results.

Decision-making perspectives:

• Technical decision-makers: Control of heat treatment, surface hardening and weld seams.
• Purchasing/project management: Specification of permissible hardness ranges in accordance with material standards.
• Science: Correlation of hardness with microstructure and tensile strength.
• Insurance/law: Documented verification of mechanical properties in the event of quality deviations.

Typical testing or verification methods: Vickers hardness testing (macro and micro hardness), calibration with reference hardness blocks, hardness profile testing.

FAQ:

• When is Vickers hardness testing preferred?
• For thin coatings, small specimens or when a universally comparable hardness value is required.

Definition: Weld seam testing comprises all testing measures for assessing the quality and integrity of welded joints. It serves to verify that the joint meets the specified requirements. The selection of testing methods is governed by DIN EN ISO 17635.

Practical relevance: Non-destructive testing methods (NDT) such as ultrasonic testing (UT), radiography (RT), magnetic particle testing (MT) or penetrant testing (PT) identify internal and external defects. In addition, destructive tests such as tensile, bend or notched-bar impact tests can be carried out. Assessment criteria are derived from DIN EN ISO 5817 (quality levels for imperfections).

Decision-making perspectives:

• Technical decision-makers: Selection of suitable testing methods according to component requirements and safety class.
• Purchasing/project management: Definition of test classes, acceptance criteria and scope of documentation.
• Science: Analysis of weld seam microstructure, residual stresses and defect types.
• Insurance/law: Verification of standard-compliant testing and quality assurance in the event of damage.

Typical testing or verification methods: UT, RT, MT, PT, visual testing (VT), metallographic sections.

FAQ:

• Which standard governs the assessment of weld seam defects?
• DIN EN ISO 5817 defines quality levels and assessment groups for imperfections.

Definition: Welding engineering consulting is the technical advisory service for the planning, qualification and monitoring of welding processes. It covers material selection, weld seam design, procedure qualification and compliance with normative requirements. The aim is to ensure technical integrity and regulatory conformity.

Practical relevance: Consulting topics include, among others, the preparation and review of welding procedure specifications (WPS), procedure qualifications (WPQR), material combinations and heat treatment. Relevant standards are DIN EN ISO 15614 (procedure qualification), DIN EN ISO 9606 (welder qualification) and DIN EN ISO 3834 (quality requirements). Errors in welding planning can lead to cracking, distortion or susceptibility to corrosion.

Decision-making perspectives:

• Technical decision-makers: Selection of suitable welding procedures and safeguarding of safety-critical joints.
• Purchasing/project management: Assessment of supplier qualification and normative conformity.
• Science: Analysis of microstructural changes, residual stresses and heat-affected zones.
• Insurance/law: Verification of proper planning and execution in the event of damage.

Typical testing or verification methods: Document review (WPS/WPQR), weld seam testing (UT, RT), metallographic analysis, hardness testing.

FAQ:

• When is welding engineering consulting required?
• For safety-relevant constructions, new material combinations or increased regulatory requirements.

Definition: The welding procedure qualification test is the qualifying proof that a defined welding procedure, under specified parameters, reproducibly achieves the required quality. The result is documented in a welding procedure qualification record (WPQR). The requirements are governed by DIN EN ISO 15614.

Practical relevance: The test comprises welding a test piece under realistic conditions as well as subsequent destructive and non-destructive testing. Typical tests are the tensile test, bend test, notched-bar impact test, hardness testing and macroscopic examination. The qualified parameters (e.g. current, heat input, material group) define the validity range of the WPS.

Decision-making perspectives:

• Technical decision-makers: Ensuring the process stability and mechanical performance of the welded joint.
• Purchasing/project management: Requiring valid WPQR documents as a prerequisite for awarding contracts.
• Science: Analysis of heat-affected zones, microstructural transformations and residual stresses.
• Insurance/law: Proof of standard-compliant procedure qualification in cases of damage.

Typical testing or verification methods: Tensile test, bend test, notched-bar impact test, hardness testing, macroscopic section examination, NDT.

FAQ:

• What is the difference between WPS and WPQR?
• The WPS describes the welding procedure, while the WPQR documents its successfully tested qualification.