Identifying the cause of corrosion or rupture in metal piping
A leak, cracking, or rupture in pipework cannot be reliably explained by simple visual inspection.
The metal retains the trace of the thermal, mechanical, and chemical stresses it has undergone: local work hardening, changes in the steel grain structure, carbide precipitation, the presence of inclusions, localized corrosion, or intergranular attack.
In practice, only a Pipework Metallographic Inspection makes it possible to distinguish a grade defect, a heat-treatment nonconformity, chemical contamination of the fluid, galvanic coupling, corrosion fatigue, or accidental overload. The fracture surface never lies: it contains the history of the stresses endured by your installation.
Reading the metal’s memory at the microstructural level
Metallographic examination reveals what no macroscopic inspection can demonstrate on its own: grain size, heterogeneities, phase transformations, work-hardened zones, decarburization, precipitation, segregation, and the morphology of corrosion attack. In austenitic stainless steel, for example, sensitization linked to carbide precipitation at grain boundaries can point to an intergranular corrosion diagnosis.
In carbon or alloy steel, observing the microstructure makes it possible to identify a heat-treatment anomaly, overheating, or a grade mismatch with the intended service.
Combining observations, mechanical measurements, and analytical chemistry
The laboratory uses a coherent set of techniques depending on the case under study: optical microscope for micrographic examination, a hardness tester to compare local hardness values, ICP and elemental analyzers to verify composition and grade, as well as C/S, N/O, or H contents when the context requires it. These data make it possible to compare the part with its specifications, look for material nonconformity, and assess the effect of service on local properties.
Establishing technical responsibility based on measurable facts
A properly conducted metallurgical inspection makes it possible to answer decisive questions for maintenance managers, design offices, court experts, and manufacturers: is the grade compliant? Is the microstructure compatible with the service? Is the fracture prior to or subsequent to corrosion? Is there embrittlement due to the environment, corrosion fatigue, intergranular corrosion, attack under deposits, or external chemical contamination?
By providing microstructural and analytical evidence, the inspection helps distinguish a material defect from an operational error or an uncontrolled environment.
Carrying out a complete metallurgical investigation to determine the failure
The approach is based on a multi-scale reading of the failed part and, if possible, of a sound reference area for comparison.
We combine metal failure analysis, fractographic examination, micrographic cross-sections, hardness measurements, chemical composition verification, and identification of corrosive species. This methodology makes it possible to establish a well-supported technical scenario: brittle fracture, ductile fracture, fatigue, corrosion-assisted failure, intergranular corrosion, or interaction between the environment and the microstructure.
👉The goal is to remove uncertainty about liability for the loss and to guide robust corrective actions.
Clearly identifying the fracture mode
Fractographic analysis under the optical microscope, then under a stereomicroscope and through SEM-EDX inspection, makes it possible to recognize the markers of ductile, brittle, transgranular, intergranular, or fatigue fracture.
Initiation points, striations, dimples, cleavage facets, corrosion products, and foreign deposits tell the real failure scenario.
Comparing the fractured zone with the unbroken zone strengthens the interpretation and makes it possible to highlight any material nonconformity, progressive damage, or the action of foreign agents.
Deploying a multi-scale inspection from the surface to the core of the metal
For surfaces, deposits, and corrosion products, the investigation relies on SEM-EDX, ICP-AES, XPS, and, as needed, electrochemical tests such as OCV, LSV, EIS, or galvanic coupling.
This approach makes it possible to semi-quantitatively identify oxidizing or corrosive agents, characterize surface chemistry, assess coating performance, track thickness loss, or reproduce behavior under accelerated aging.
👉The issue is not only to observe the corrosion, but to characterize its origin and mechanism.
Recommending lasting corrective actions
Beyond the findings, the laboratory issues operational recommendations: selection of a substitute alloy, adjustment of a heat treatment, improvement of a coating, modification of a fluid or cleaning process, reduction of critical roughness, control of galvanic coupling, or adjustment of process conditions.
This solution-oriented guidance aims to secure recommissioning and prevent recurrence of the damage on the installation or on similar equipment.
Act quickly to preserve evidence and ensure a reliable diagnosis
The investigation should be initiated as soon as a crack, leak, abnormal corrosion, suspicious deposit, or any in-service rupture appears. The earlier the sample is taken and preserved without alteration, the more reliable the interpretation of the fracture surface and corrosion products will be.
Rapid response also makes it possible to compare sound and failed areas, secure similar equipment still in operation, and immediately guide maintenance, insurance, or legal decisions.
Frequently asked questions
How can the true origin of a pipe rupture be determined between material defect, corrosion, and operational error?
Why is metallographic examination essential in a pipework inspection?
What analytical methods should be used to investigate corrosion or a pipe rupture?
What can a metallurgical inspection conclude in the event of an industrial loss?
When should a metallographic investigation be launched on a failed pipeline?
