April 7, 2021

Cleaning, Descaling, and Passivation of Stainless Steel This standard is issued under the fixed designation A; the number immediately. Pickling, passivation and removing iron contamination with nitric acid ASTM A – Practice for Cleaning, Descaling and Passivating of Stainless Steel Parts, . Passivation per ASTM A Posted on November 29, Latest News. APT to Exhibit at SHOT Show in Las Vegas, NV. Advanced Plating.

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Article: Passivation of stainless steels

It is the pzssivation of the user of this standard to establish appropriate safety and health practices w380 determine the applicability of regulatory limitations prior to use. Precaution shall always be practiced to minimize iron contamination, in reuse of cleaning and pickling solution, in water rinsing, in circulation of cleaning solutions and rinse water, in protection of cleaned surfaces, for safety, and disposal of used solutions and water.

The treatments are then defined by the process classes.

Tests passiivation acceptance criteria to demonstrate that the passivation procedures have been successful are listed in 7. Although they apply primarily to materials in the composition ranges of the austenitic, ferritic, martensitic, and duplex stainless steels, the practices described may also be useful for cleaning other metals if due consideration is given to corrosion and possible metallurgical effects.

We’ve been in the metal finishing business for over 80 years.

Unless otherwise specified, it is this definition of passivation that is taken as the meaning of a specified requirement for passivation. Having been in the metal finishing industry for nearly a century, Keystone Corporation meets the qualified standards of ASTM A and is well qualified to handle your passivation needs.


Asttm standard notes that the high carbon martensitic stainless steels, such as C, are not suitable for acid passivation as they can be attacked or be subject to hydrogen embrittlement.

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Passivation of stainless steels Introduction Stainless steels are designed to naturally self-passivate whenever a clean surface is exposed to an environment that can provide enough oxygen to form the chromium rich oxide surface layer, on which the corrosion resistance of these alloys depends. The selection of procedures from this practice to be applied to the parts may be specified upon agreement between the supplier and the purchaser.

Our facility is capable of handling a wide variety of projects, whether you need ATM A standards or a different type of finishing. Others, such as food-handling, pharmaceutical, aerospace, a308 certain nuclear applications, may require extremely high levels of cleanness, including removal of all detectable residual chemical films and contaminants that are invisible to ordinary inspection methods. Regards, Ted Mooney, P.

Although cannot see the reason obviously myself?

Some of the various meanings associated with the term passivation that are in common usage include the following:. Specifications for passivation treatments for stainless steels Passivatiln the American a30 have been used. Passivation often follows the process of pickling. It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages.

Unlike ASTM A, the standard does not require specific solutions for particular stainless steel grades or types, although 3 specific treatments are identified.

ASTM A – Stainless Steel Passivation by Keystone Finishing

In some cases, no more than degreasing or removal of gross contamination is necessary. This practice covers the standard recommendations and precautions for cleaning, descaling, and passivating of new stainless steel parts, assemblies, equipment, and installed systems.

In the case of classes C3 and C4, a two step process is defined, with a clean water rinse between the two steps, shown in the table below. Recommended cleaning practices shall be followed for welds and weld-joint areas, specially critical applications, installed systems and post-erections.


All information presented is for general reference and does not represent a professional opinion nor the policy of an author’s employer. Precision inspection shall be performed by solvent-ring test, black light inspection, atomizer test, and ferroxyl test. To my knowledge it is not possible to do a combination pickling and passivation. While the practice provides recommendations and information concerning the use of acids and other cleaning and descaling agents, it cannot encompass detailed cleaning procedures for specific types of equipment or installations.

On the other hand, some of the practices may be applicable for these purposes. The standard also allows any combination of citric acid concentration, temperature and time, provided that the passivation test criteria can be met.

It is also quite out of date and needs to be updated.

It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application.

Visual inspection; wipe tests; residual pattern; water-break test; free iron test such as water-wetting or drying; high-humidity test; and copper sulfate test. This standard covers both nitric and citric acid treatments. Our facilities are capable of handling both large and small parts. In order to avoid ambiguity in the setting of requirements, it may be necessary for the purchaser to define precisely the intended meaning of passivation.