ASTM B858-06(R2018) pdf free download

ASTM B858-06(R2018) pdf free download.Standard Test Method for Ammonia Vapor Test for Determining Susceptibility to Stress Corrosion Cracking in Copper Alloys
1. Scope
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 in- tended to create an environmental condition of reproducible severity. N OTE 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 Annex A1 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 standard. No other units ofmeasurement 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
5. Significance and Use
5.1 This test method is an accelerated test to determine if a copper alloy product will be susceptible to stress-corrosion cracking when exposed to a particular atmospheric condition during service with the appropriate risk level—see Annex A1. 5.1.1 This test method is generally intended to determine if a copper alloy product will crack because of internal stresses when subjected to the test, and is not intended for testing assemblies under applied stress. Ifused for this purpose, it shall be for information only and not a cause for rejection of the assembly, its component parts, or the original mill product.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such specifications are available. 3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. 7.2 Purity ofWater—Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by Type IV or better, of Specification D1193. 7.3 Ammonium Chloride Solution (4N)—Dissolve 107 g of ammonium chloride (NH 4 Cl) in water and dilute to 500 mL. Store the solution in a closed vessel. 7.4 Hydrogen Peroxide (H 2 O 2 ), 30 to 35 % technical grade. (Warning—Hydrogen peroxide in high concentrations can cause severe skin burns. Use of proper safety equipment is advised.) 7.5 Sodium Hydroxide Solution (300 to 500 g/L)—Dissolve 300 to 500 g of sodium hydroxide (NaOH) into water and dilute to 1 L. (Warning—Sodium hydroxide can cause chemi- cal burns to the skin and eyes. Use of proper safety equipment is advised.) 7.6 A clean organic solvent or hot alkaline solution that contains no ammoniacal-type groups or substituents. 7.7 Sulfuric Acid Solution (50 mL/L)—Slowly add 50 mL of concentrated sulfuric acid (H 2 SO 4 ) into water and dilute to 1 L.