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2.改变部分牌号的表示方法 (1)一些用代号标记的材料 这些材料用力学性能或化学成分标记。 ①“普通碳素结构钢”(GB700—79)改名为“碳素结构钢”(GB700—88)。原标准中将钢分为甲、乙、特
2. To change the way some of the grades (1) Some of the material marked with the code These materials are marked with mechanical properties or chemical composition. ① “ordinary carbon structural steel” (GB700-79) renamed “carbon structural steel” (GB700-88). The original standard will be divided into A, B, special