【国外标准】 Standard Specification for Fine Silver Electrical Contact Fabricated Material (Withdrawn 2019)

This specification covers fine silver electrical contact fabricated material. The forms covered are tubing, rod, wire, strip, and sheet for electrical contact applications. The sheet and strip shall conform to the required mechanical properties such as tensile strength, elongation, and hardness. The wire and rod shall conform to the required mechanical properties such as tensile strength and elongation. The material shall be produced by either hot or cold working operations. It should be finished by such cold working and annealing as may be necessary to meet the properties specified. All materials produced to this specification shall be inspected visually. 1.1 This specification covers fine silver grade 99.9 % in fabricated form. The forms covered are tubing, rod, wire, strip, and sheet for electrical contact applications. 1.2 The electrical contact properties may vary dependent upon the method of manufacture (refer to 6.3). 1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.4 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 become familiar with all hazards, including those identified in the appropriate Material Safety Data Sheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use. TABLE 1 Chemical CompositionA ElementWeight % Silver 99.90 min (by difference) Silver and copper 99.95 min Copper 0.10 max Nickel 0.002 max Cadmium 0.005 max Zinc 0.005 max Lead 0.025 max Iron 0.005 max Aluminum 0.002 max Bismuth 0.001 max Total others 0.05 max Total of all impurities 0.10 max A Elements, such as phosphorus, sodium, and lithium are not natural impurities in this grade of silver and thus are not normally found in any appreciable quantities. However, since they may be detrimental for certain electrical contact applications, limits for these and other elements may be established by agreement between the purchaser and manufacturer. Refer to 7.2. TABLE 2 Mechanical Properties of Sheet and Strip Note—These hardness values are listed as “Typical,” because of the difficulty in establishing a range meaningful for all the thicknesses possible. If the purchaser desires hardness specifications, rather than tensile strengths, he shall reach agreement with the supplier as to the proper and suitable hardness scale and range for the particular size and form ordered. TemperReduction in B & S Numbers (Reference)Percent Reduction (Reference)Ultimate Tensile Strength, psi (MPa) Minimum Elongation in 2-in. (51 mm), %Typical (see Note 1) Hardness Rockwell, 15 T MinimumMaximum Annealed0 024 000 (165)30 000 (207) 25 59 max ½ H221 30 000 (207)37 000 (255) 8 72 Hard43737 000 (255)44 000 (303) 3 76 Spring86044 000 (303)51 000 (352) 1 80 TABLE 3 Mechanical Properties of Wire and Rod TemperReduction in B & S Numbers (Reference) Percent Reduction (Reference)Ultimate Tensile Strength, psi (MPa)Minimum Elongation in 2 in. (51 mm), % MinimumMaximum Annealed0 024 000 (165)30 000 (207) 25 1/8H½1126 000 (179)33 000 (228) 15 ¼ H12130 000 (207)37 000 (255) 4 ½ H23739 000 (269)46 000 (317) 4 Hard46042 000 (290)49 000 (338) 2 Spring88446 000 (317)54 000 (372) 1