Passivation is a chemical treatment applied to stainless steel parts to provide resistance to oxidation, rusting and mild chemical attack. The Passivation process. A - 05 Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts Format, Pages, Price. PDF ASTM License Agreement. Sep 1, This standard is issued under the fixed designation A ; the number immediately following the designation indicates the year of This specification is under the jurisdiction of ASTM Committee A01 on Steel, . A - 05€.
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This standard is issued under the fixed designacion A the number ittimediately 1 This specification is under the jurisdiction of ASTM Comites m Steel. Nov 1, ASTM A - Designation: A – 05 Standard Speci?cation for Chemical Passivation Treatment. Designation: A 05e1. Standard Specification for. Chemical Passivation Treatments for Stainless Steel Parts1 This standard is issued under the fixed.
Originally approved in Last previous edition approved in as A — 01e1. Such treatments, also sometimes called passivation in common usage, are designated as post-cleaning treatments in this speci? The surface of stainless steel that has been pickled is free of scale, free iron, and exogenous foreign matter, and does not require a separate treatment for passivation as de? The passivation process de? The surface of stainless steel resulting from these treatments is free of scale, free iron, and exogenous foreign matter, and does not require a separate treatment for passivation as de?
Statements regarding chemical treatments, unless otherwise speci?
Ordering Information 4. Determination of the suitability of this speci? Materials and Preparation for Passivation Treatments 5. The effectiveness of a particular treatment for a particular grade of stainless steel in a particular application is demonstrated by meeting the speci?
Attention shall be given to maintaining adequate volume, concentration, purity, and temperature control appropriate to the size and amount of stainless steel to be treated.
Such records shall be available for inspection when speci? The processor is not required to reveal the precise composition of proprietary chemical mixtures but shall maintain a unique identi? When electrochemical cleaning is required, it shall be performed in accordance with Practice B Treatments in Nitric Acid Solutions 6.
Treatments in Citric Acid 7. Immersion bath to be controlled at a pH of 1. Such treatments may include externally applying an electrical potential on the stainless steel parts, as in the case of electropolishing.
The suitability of such passivation treatments for use in 3 meeting the requirements of this speci? Neutralization 9. NOTE 1—The selection of medium and procedures for a neutralization depends of the chemistry of the passivation and on economic considerations. Post-Cleaning Treatments An example of a medium that serves to accelerate the formation of the passive?
The parts shall then be thoroughly dried. Finish Testing Agency Lot, Frequency of Testing, and Selection of Test Not all of the following tests are suitable for all grades of stainless steel.
See Note 2. NOTE 2—Some of the tests may produce positive indications not associated with the presence of free iron on the stainless steel surface.
An example would be application of Practice C on some lesser-alloyed martensitic or ferritic stainless steels. Practice D—Copper Sulfate Test This test shall not be applied to parts to be used in food processing. At the end of this period, the surface shall be carefully rinsed and dried with care taken not to disturb copper deposits if present. It is recommended for detection of free iron on austenitic and series stainless steels.
This test is not recommended for detection of free iron on ferritic or martensitic series stainless steels, because these steels will give a positive indication irrespective of the presence or absence of anodic surface contaminants. The test solution shall be mixed fresh on the day of the test. The formation of a dark blue color within 30 s denotes the presence of metallic iron.
Practice A—Water Immersion Test This cycle shall be repeated a minimum of twelve times. Practice B—High Humidity Test Practice C—Salt Spray Test Practice F—Free Iron Test It is especially useful for large parts that have been uniformly cleaned but that are inconvenient for reasons of size of equipment or ease of handling of the part to place in the environments de? Passivation is a process of making stainless steel more stainless than it would be if left alone. It is based on using an acid nitric or citric under highly controlled conditions to remove free iron particles from the surface and to help form a metal oxide layer that increases its ability to resist rusting.
It is important to understand that passivation is not a coating applied to the surface; it is a process that makes the surface itself more resistant to staining or rusting. The current and previous versions describe the process and the specific parameters when using nitric acid or citric acid.
Each acid has several specific combinations of concentration, temperature, and required time as well as other specific requirements. Both versions also describe a number of different tests which can be used to determine the effectiveness of the process. The first difference is the addition of a new test which can be used instead of any of the current tests which are continued. The new test is a boiling water immersion test.
In addition to this new test, there are slight modifications to several of the existing tests. The second difference is that the copper sulfate test can now be applied to parts used in food processing.
The third important difference is in appendix X1 which states that restrictions on certain high-strength grades such as C that is subject to hydrogen embrittlement are limited to nitric acid and these restrictions do not apply to citric acid passivation. The fourth significant difference is the addition of appendix X2 which serves as a general guide for the selection of a passivation treatment for different grades of stainless steel.
The new version clarifies a number of specific details, adds an additional new test, removes restrictions on testing parts used in food processing, clarifies restrictions applying to high-strength steels subject to hydrogen embrittlement and adds clarifying information in the new addendum X2.
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