---
type: "WebPage"
title: "Stainless steel analysis laboratory according to ISO 3651-1"
description: "As an industrialist, you wish to carry out analyses of stainless steels according to the ISO 3651-1 standard Why analyze the corrosion resistance of stainless steels according to ISO 3651-1? ISO 3651-1 defines a test method for evaluating the susceptibility..."
resource: "https://filab.fr/en/our-services/our-analysis-services/metallurgical-analysis-laboratory/stainless-steel-analysis-iso-3651-1/"
tags: ["EN", "pll_6916ed76ba49e", "Arnaud JOUDRAIN Meta"]
timestamp: "2026-04-22T08:13:08Z"
published: "2025-11-14T09:35:27Z"
language: "en"
author: "Laure Durieux"
---

# Stainless steel analysis laboratory according to ISO 3651-1

## As an industrialist, you wish to carry out analyses of stainless steels according to the ISO 3651-1 standard

### Why analyze the corrosion resistance of stainless steels according to ISO 3651-1?

**ISO 3651-1** defines a test method for evaluating the susceptibility of [stainless steels](https://filab.fr/en/our-services/our-analysis-services/metallurgical-analysis-laboratory/stainless-steel-laboratory-analysis.md) to **intergranular [corrosion](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/laboratory-expertise-and-analysis-of-corrosion.md)**. This test is essential to ensure the durability, mechanical strength, and regulatory compliance of your materials, particularly in demanding sectors such as [aerospace](https://filab.fr/en/sectors-of-activity/laboratory-analysis-aeronautics-aerospace.md), [medical devices](https://filab.fr/en/sectors-of-activity/laboratory-analysis-medical-devices.md), [energy](https://filab.fr/en/sectors-of-activity/laboratory-analysis-nuclear-energy.md), [chemicals](https://filab.fr/en/our-services/our-analysis-services/chemical-analysis-laboratory.md), [automotive](https://filab.fr/en/sectors-of-activity/laboratory-analysis-automobile.md), and [luxury](https://filab.fr/en/sectors-of-activity/laboratory-analysis-luxury-goods.md) goods.

When your components are exposed to corrosive environments, a lack of resistance can lead to breakage, non-conformities, production stoppages, or in-service failures. It is precisely to avoid these risks that ISO 3651-1 is used as a global standard.

### Our stainless steel analysis services according to ISO 3651-1

**Analysis according to ISO 3651-1**: implementation of the test of exposure to corrosive solutions defined by the standard.

**[Metallographic analysis](https://filab.fr/en/our-services/our-analysis-services/metallurgical-analysis-laboratory/examination-metallographic-section-laboratory.md)**: observation of the [microstructure](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-failures/laboratory-of-microstructure-analysis-of-materials.md) before and after testing to detect precipitation, localized attacks, decarburization, etc.

**R&D support and materials optimization**: development or improvement of alloys, treatments, welding processes or coatings adapted to your constraints.

**Assessment of sensitivity to intergranular corrosion**: observation of affected areas, measurement of the level of metallurgical attack, comparison to normative thresholds.

**Expertise and interpretation of results**: our materials engineers interpret the corrosion mechanisms and identify the causes: [heat treatment](https://filab.fr/en/our-services/our-analysis-services/laboratory-surface-characterization/analysis-of-hardened-heat-treatment-on-steel-in-the-laboratory.md), [welding](https://filab.fr/en/our-services/our-analysis-services/metallurgical-analysis-laboratory/characterization-welding-scrapings.md), environment, composition…

## Our technical resources

 To perform corrosion analyses on your stainless steels, the FILAB laboratory uses various cutting-edge analytical techniques: [### SEM FEG-EDX](https://filab.fr/en/our-technical-resources/laboratory-analysis-sem-scanning-electron-microscopy.md) [### ICP-MS ou ICP-AES](https://filab.fr/en/our-technical-resources/laboratory-analysis-icp-icp-ms-icp-aes.md) [### Salt spray](https://filab.fr/en/our-technical-resources/laboratory-salt-spray-corrosion-tests.md) [### Optical Microscope](https://filab.fr/en/our-technical-resources/laboratory-of-analysis-and-observation-by-optical-microscope-mo.md) [### XPS](https://filab.fr/en/our-technical-resources/laboratory-analysis-xps-esca.md) [### XRD](https://filab.fr/en/our-technical-resources/x-ray-crystallography-laboratory-xrd.md)
## The FILAB laboratory assists you in the analysis of stainless steels according to the ISO 3651-1 standard

### Why choose FILAB for stainless steel analysis according to ISO 3651-1

For over 30 years, the FILAB laboratory has been putting its expertise and state-of-the-art [analytical resources](https://filab.fr/en/our-services.md) at the service of businesses, offering comprehensive corrosion expertise.

From analysis to in-depth study of corrosion phenomena, we support you with customized solutions tailored to your industrial challenges.

## Our solutions in steel analysis and expertise

[Metallographic analysis](https://filab.fr/en/our-services/our-analysis-services/metallurgical-analysis-laboratory/examination-metallographic-section-laboratory.md) of a steel

Analysis of welds on steels

Study of fracture surfaces on steels

[Ageing study](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/laboratory-material-testing/filab-accelerated-ageing-test-laboratory/) (corrosion phenomena, surface alteration, etc.) on steels

[Measurement of coating thicknesses](https://filab.fr/en/our-services/our-analysis-services/laboratory-surface-characterization/surface-coating-thickness-measurement.md) on steel metal parts

[Corrosion resistance study](https://filab.fr/en/our-services/our-expertise-services/laboratory-analysis-deposit-contamination/laboratory-expertise-and-analysis-of-corrosion.md) on steels

[Analysis and characterization of surfaces](https://filab.fr/en/our-services/our-analysis-services/laboratory-surface-characterization.md) (roughness, defects, etc.) on steels

### Accreditation

This [Nadcap accreditation](https://filab.fr/en/about-us/accreditations-en/materials-testing-nadcap-laboratory.md) notably covers:
✔️ Chemical analysis (ICP-OES) of critical metallic alloys (Al, Fe, Ni, Ti)
✔️ Metallography

An international recognition that confirms our commitment to quality and reliability for the most demanding applications, particularly in the aerospace sector.

 ![](https://filab.fr/wp-content/uploads/2026/04/PNG-bleu-e1775737225243-1024x446.png) [Explore our accreditations](https://filab.fr/en/about-us/accreditations-en.md)
## FAQ

 What are the common industrial applications of analysis according to ISO 3651-1?
- Stainless steel batch qualification
- Welding process validation
- Conformity testing of components exposed to corrosion
- Investigation of in-service failures or breakages
- Heat treatment optimization

 What is the ISO 3651-1 standard?
This is an international standard that describes an **intergranular corrosion test** applied to stainless steels. It defines the immersion conditions in a corrosive solution to assess the material's susceptibility to intergranular attack.

 Does ISO 3651-1 correspond to an analytical technique?
No. ISO 3651-1 defines a **test protocol** (exposure to a corrosive environment), not an instrumental technique.
The analysis of the resulting corrosion can then be performed using tools such as **metallography, optical microscopy, or scanning electron microscopy (SEM)**.

 What types of stainless steel are involved?
The test is primarily applicable to stainless steels:

- austenitic,
- ferritic,
- stabilized or unstabilized,
- used in corrosive or demanding environments.

 What is the principle of the test?
The material is:

- Prepared in test specimen form,
- Immersed in a corrosive solution defined by the standard,
- Rinsed and examined after exposure for signs of intergranular attack.

 What is the difference between ISO 3651-1 and ISO 3651-2?
- **ISO 3651-1**: Immersion test for austenitic and ferritic stainless steels.
- **ISO 3651-2**: Electrochemical test (DL-EPR method) for detecting corrosion sensitization.