Standard Specification for Electrodeposited Coatings of Tin
标准状态
基本信息
标准简介
Designation: B545-13 Standard Specification for Electrodeposited Coatings of Tin11. Scope1.l This specification covers the requirements for electrode-posited (electroplated) coatings of tin applied to metallicarticles. Tin coatings are used to provide a ow contact-resistance surface.to protect against corrosion (see 1.2).tofacilitate soldering, to provide anti-galling properties,and to bea stopoff coating in thc nitriding of high-strength stecls.1.2 Some corrosion can be expected from tin coatingsexposed outdoors. In normal indoor exposurc, tin is protectiveon iron, steel, nickel, copper. and their alloys. Corrosion can beexpected at discontinuities in the coating (such as pores) due togalvanic couples formed bctween the tin and the underlyingmetal through the discontinuities.especially in humid atmo-spheres.Porosity increases as the coating thickness decreases.so that minimum thicknesses must be specified for cachapplication. Parts coated with tin can be assembled safely incontacr with iron and steel, tin-coated aluminum. yellowchromated zinc. cadmium, and solder coatings. (See Xs.1 foroxidation and corrosion propertics.)1.3 This specification applies to electroplated coatings ofn