Standard practice for determining the susceptibility of stainless steels and related nickel - chromium - iron alloys to stress - corrosion cracking in polythionic acids 不锈钢及有关镍铬铁合金在连多硫酸中应力腐蚀断裂灵敏性测定的标准实施规程
百科解释
Polythionic acid is an oxoacid which has a straight chain of sulfur atoms and has the chemical formula H2SnO6 (n > 2). Trithionic acid (H2S3O6), tetrathionic acid (H2S4O6) are simple examples.