精冲用钢一般采用低、中碳素钢或合金结构钢、低合金高强度钢和一些高碳工具钢。为了使零件经精冲后的冲裁面光洁度达到▽_(6-8)级的要求,同时减少精冲模具磨损,所用钢带须经过适当的球化软化处理。含碳量超过0.35％C的碳素钢和强韧钢,精冲前都必须经过球化处理,而且球化率最好达到100％。但过去机械加工只对 Fine blanking steel generally use low, medium carbon steel or alloy structural steel, low alloy high strength steel and some high-carbon tool steel. In order to make the finished parts after fine blanking surface finish ▽ _ (6-8) level requirements, while reducing the fine blanking die wear, the steel used to be appropriate ball softening treatment. Carbon steel with carbon content over 0.35% C and tough steel must be spheroidized before fine blanking, and the nodulizing rate should preferably reach 100%. But in the past machining only