Metallurgical analysis (structural steel) according to NF EN 10025-2 in the laboratory

Themetallurgical analysis of structural steel products according to NF EN 10025-2 enables the construction sector to verify that the material is suitable for the requirements of use, manufacturing and implementation. This approach applies in particular to sheets, plates, sections and rolled products intended for metal structures, industrial equipment and welded assemblies. In practice, laboratory testing helps confirm consistency between the stated grade, the observed metallurgical condition and the product’s expected performance. It is part of a quality control, material expertise, non-conformity investigation or supplier acceptance support process. To learn more about the available resources, discover our Laboratoire analysis Met.

The NF EN 10025-2 standard sets out the technical delivery conditions for flat and long products in non-alloy structural steels. In the context of laboratory expertise, it serves as a basis for linking the material designation to its expected characteristics. The analysis is not limited to a simple document review: it aims to compare the declared elements with the observations and results obtained on test specimens or representative samples. Depending on the issue, this approach can be supplemented by fracture or low-temperature performance examinations via the Laboratoire analysis Cryo Met.

For a structural steel, the laboratory can carry out complete metallographic preparation followed by optical microscopy examination and, if necessary, higher-magnification observations. The services available include microstructure characterization, grain size measurement, inclusion rating, and the search for local heterogeneities. These analysis are particularly relevant for assessing the impact of a rolling process, heat treatment, welding operation, or manufacturing incident.

The methodology begins with defining the technical need and the applicable reference standard. The laboratory then establishes an analysis plan, including sample selection, section orientation, and preparation conditions. The samples are mounted, polished, and then etched if necessary to reveal the microstructure. Observations are carried out using optical microscopy, with the option of complementary examinations depending on the level of detail required. When thermal investigations are useful to understand material behavior, specialized resources such as Laboratoire analysis Atg can be integrated into the overall expertise.

The NF EN 10025-2 analysis process is based on a structured sequence: defining the need, document review, sampling strategy, metallographic preparation, macro- and micrographic examinations, complementary tests, and interpretation of the results. Depending on the purpose of the file, the laboratory may combine microstructure observation, grain size measurement, assessment of inclusion cleanliness, verification of decarburization depth, or examination of coatings on cross-sections. Surface and cross-section observations can also be taken further via the Laboratoire Analyse Meb when the required resolution justifies it.

The technical requirements investigated concern the metallurgical consistency of the product: structural homogeneity, phase morphology, rolling condition, presence of inclusions, grain size, possible surface decarburization, or microstructural peculiarities. Depending on the need, recognized methods may be used, for example grain size measurement according to ASTM E112 or NF EN ISO 643, inclusion rating according to ISO 4967, ASTM E45-18a or NF A04-106, as well as decarburization depth according to EN ISO 3887.

Depending on the product’s intended use and the risks identified, additional checks may be carried out: decarburization depth measurement, coating examination on a cross-section, analysis of heat-affected zones, or investigation of material defects. For broader characterization needs covering materials and processes, it is also possible to rely on Laboratoire analysis Met and on advanced investigation resources in microscopy and metallographic sectioning.

The results are interpreted in light of the initial request, the material’s expected characteristics, and the methods used. The report may include annotated micrographs, measurements, a description of the observed structure, identification of any deviations, and a technical conclusion that can be used by quality, methods, purchasing, or industrialization teams. This output facilitates decision-making for material acceptance, non-conformity analysis, or the definition of corrective actions.

Within an industrial project, metallurgical analysis supports the material quality justification process. It can be used to complete an incoming inspection file, supplier qualification, process validation, or deviation handling. The typical process includes defining the applicable requirements, selecting the relevant tests, carrying out the examinations using recognized methods, and then issuing a technical report that can be used within the customer’s quality system. Depending on the level of criticality, this approach can be integrated into a broader strategy for materials characterization, surface inspection, or failure investigation.