Corrosion identification expertise on parts in the laboratory

A corrosion observed on a metal part can have multiple causes: aggressive environment, coating defect, surface contamination, material heterogeneity, galvanic coupling, or process drift. For an industrial company, the challenge is to quickly determine the mechanism involved in order to secure production, address the nonconformity, and avoid recurrence in service. Our laboratory supports manufacturers and users of metal materials in the corrosion identification on parts, from observing the first clues to identifying the root causes.

The expertise may include a fractographic analysis to characterize brittle, ductile, or fatigue fracture, observation of the fracture surface to highlight signs of corrosion, comparison of sound and failed areas by hardness and microstructure, as well as determination of the composition of the metal part. In the event of a surface defect, the examination makes it possible to identify wear, irregularities, cracks, topographic defects, coating nonconformities, or abnormal roughness. These investigations naturally fit within the services of Laboratoire Materiaux.

To anticipate failures before industrialization, the laboratory assesses a part’s corrosion resistance through accelerated aging and tests in simulated environments. Studies may cover bare materials, coatings, paints, surface treatments, or assemblies of dissimilar metals. The objective is to compare solutions, rank risks, and validate the robustness of a technical choice under representative service conditions.

The effectiveness of a corrosion expertise relies on combining several levels of analysis: surface, cross-section, deposit, metal matrix, and environment. The laboratory relies on microscopic observations, elemental analysis, and behavior tests to link visible damage to its physico-chemical mechanism. This approach makes it possible to move from a finding of corrosion on parts to a conclusion that can be used for quality, production, or R&D.

Our corrosion expertise approach combines multi-scale observations, chemical analysis, electrochemical tests, and metallographic examinations. It makes it possible to characterize the corrosion mode, assess the oxidation state, look for corrosive or oxidizing agents, verify material compliance, and check the homogeneity of a surface treatment. This approach applies equally to failure investigations, validation studies before industrialization, coating comparisons, and process quality monitoring.

Depending on the need, the laboratory uses SEM-EDX for morphology and local composition, FEG-SEM and FEB-EDX SEM for detailed surface and deposit observation, optical microscopy for metallographic cross-sections, ICP-AES for trace elements, XPS for surface chemistry, XRD for crystal structure, as well as hardness measurements and C/S, N/O, H elemental analyzers. For surface observations, our Laboratoire Analyse Meb provides a particularly relevant level of insight.

The test methods include measurement of the open-circuit potential OCV, determination of the corrosion rate by LSV, electrochemical impedance spectroscopy EIS, and the study of galvanic coupling. Salt spray tests and simulations of specific media can also be carried out: seawater, chlorides, extreme pH, acidic or basic solutions, inhibiting media. This approach is particularly useful for parts produced by innovative processes, including Fabrication Additive Pieces Metalliques.

The main resources available are the potentiostat, salt spray chambers, optical microscope, hardness tester, SEM-EDX, FEG-SEM, FEB-EDX SEM, ICP, XPS, XRD, and elemental analyzers. These instruments make it possible to characterize deposits, detect precursors such as halogens or contamination, measure coating thickness loss, verify a material grade, and document process compliance. For additional characterization needs, also see Laboratoire Materiaux.

Filab supports manufacturers in the metallurgy sector and users of metallic materials throughout the entire product lifecycle: failure analysis, compliance testing, comparative coating studies, R&D support, design of experiments, simulation of specific environments, and tailor-made training. The laboratory works with a decision-oriented approach: understanding the origin of corrosion, validating the resistance of a material or process, then defining the actions to take to ensure the long-term reliability of parts and assemblies.