ASTM A967 analysis laboratory
As a manufacturer, you want to carry out an ASTM A967 analysis of your stainless steels
What is ASTM A967?
The ASTM A967 specification specifies the requirements for chemical finishes for stainless steels. It covers several passivation methods designed to improve the corrosion resistance of stainless steel.
The ASTM A967 standard defines several passivation methods for stainless steels, including those based on nitric or citric acid. It provides various validation tests to ensure the effectiveness of the treatment, such as the water test, the salt spray test, and the detection of free iron.
Among these tests, it includes copper sulfate (CuSO₄) analysis, which involves applying a solution to the part: the appearance of a coppery deposit indicates the presence of unpassivated iron.
What is passivation treatment?
Passivation treatment is a technique used to prevent corrosion on certain metals, such as stainless steel, aluminum and titanium. Passivation is the process of removing impurities from the metal surface, such as iron particles, oils and greases, which can cause corrosion.
Passivation treatment can be carried out in a number of different ways. However, the most common process involves immersing the metal part in a solution of nitric or citric acid. This solution dissolves impurities from the metal surface and creates a protective oxide layer that prevents corrosion.
Why have a laboratory validate a passivation treatment?
Passivation treatment is often used by the pharmaceutical industry, in medical applications and surgical implants, where corrosion can lead to health risks. It is also used in the petrochemical and shipbuilding industries to prevent corrosion of metal equipment and structures exposed to corrosive environments.
The FILAB laboratory can help you analyze your stainless steels to ASTM A967 standards
Thanks to its dual skills in chemistry and materials, the FILAB laboratory has the expertise and analytical tools needed to validate passivation treatments on stainless steel and analyze the associated treatments.
FILAB can provide a range of services related to material passivation:
Studying passivation
Study of surface evolution over time
Salt spray test to assess part degradation time
Copper sulfate analysis according to ASTM A967
Analysis of surface failures (corrosion, breakage, impurities, etc.)
Analysis according to ASTM A967/967M
Analysis of surface treatment baths
For this purpose, FILAB has a 5200m² analytical park equipped with state-of-the-art tools such as Scanning Electron Microscopes (SEM-FEG EDX) for surface studies, and several AES or CI ICPs for bath composition analysis.
FAQ
The standard provides for several validation tests after passivation, including:
- Water test (corrosion detection),
- Salt spray test,
- Free iron detection test,
- Copper sulfate test (CuSO₄).
This test involves applying a CuSO₄ solution to the stainless steel surface: the appearance of a copper deposit indicates the presence of free iron. This is a quick and qualitative method for verifying the effectiveness of the passivation treatment.
No. The standard describes several passivation methods (nitric acid, citric acid, etc.) but leaves the choice of method to the customer's requirements, the material or the end use.
Yes. It is possible to carry out post-testing to monitor the effectiveness of a passivation treatment carried out internally or by a subcontractor.
All stainless steels can be affected (austenitic, martensitic, ferritic, duplex, etc.), with particular attention to the grades and surface condition, which influence the choice of treatment and tests.
316L stainless steel is a versatile alloy widely used in many industrial sectors due to its excellent properties. Here are some of the industrial sectors that use this alloy:
- The chemical industry uses it primarily for its high corrosion resistance.
- The pharmaceutical industry uses it for the manufacture of laboratory equipment and other equipment useful for pharmaceutical production.
- The automotive industry uses it for the manufacture of engine parts, exhausts, and components.
The properties of 316L steel make it suitable for a wide range of applications. What are they?
- High resistance to corrosion
- Resistance to acids and bases
- Resistance to fatigue and wear
- Biocompatibility, making it suitable for use in the manufacture of medical devices
