ASTM International - ASTM B858-95
Standard Test Method for Ammonia Vapor Test for Determination Susceptibility to Stress Corrosion Cracking in Copper Alloys
|Publication Date:||10 October 2001|
|ICS Code (Copper and copper alloys):||77.120.30|
1.1 This test method describes a procedure to determine the presence of residual stresses in wrought copper alloy products that may lead to stress corrosion cracking. An ammonia vapor atmosphere is used as an accelerated test.
1.2 This test method is only suitable for products fabricated from copper alloys that are known to be susceptible to stress corrosion cracking in ammonia vapor atmospheres. It is intended to create an environmental condition of reproducible severity.
Note 1-It is well known that the critical step in the cracking mechanism is the development of an environment in the condensate film that occurs on the surface of the test specimen, and is rich in copper complex ions.
1.3 The severity of this test method depends upon the pH of the corrosive solution. In are given four different atmospheres to which the product may be exposed, and the appropriate pH of the solution to be used for the test, depending on the risk level associated with the intended application.
1.3.1 The appropriate pH value for the test shall be specified in the product specification, or as per established agreement between the supplier and purchaser, with respect to the alloy and its intended application.
1.4 Units-The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.