一、前 言 钢材的机械性能中,在强度与塑性之间经常发生矛盾。通常,提高强度势必牺牲塑性,反之亦然。冷成型材料最早采用含碳量很低(0.1～0.2％)的低碳钢。为满足构件对强度日益增长的要求,又采取了低合金高强度钢经固溶强化、沉淀强化、晶粒细化等再 First, the foreword The mechanical properties of steel, strength and ductility often occur between the contradictions. In general, increasing strength is bound to sacrifice plasticity and vice versa. The earliest cold forming materials with low carbon content (0.1 ~ 0.2%) of low carbon steel. In order to meet the increasing requirements of the strength of the components, but also taken low-alloy high-strength steel by solid solution strengthening, precipitation strengthening, such as grain refinement