一、前言文献指出,含碳量超过1.1％的过共析钢,由于组织中过剩碳化物多,颗粒粗大,且分布往往不很均匀。在供应状态下的金相组织中,过剩碳化物多呈断续网状的特征,致使钢的韧性变坏。因而对于T12A钢,往往不用于承受冲击载荷作用下的模具中。但是,高碳钢中过剩碳化物的存在,对提高冷冲模具的硬度、强度与耐磨性,使钢的韧性变坏程度方面有着密切的关系。 I. Preface The literature points out that hypereutectoid steels with a carbon content of more than 1.1% due to excess carbide in the structure and coarse particles, are often not uniformly distributed. Metallography in the supply state, the excess carbide mostly intermittent mesh characteristics, resulting in deterioration of the toughness of steel. Therefore, for T12A steel, often not used to withstand the impact load of the mold. However, the presence of excess carbides in high-carbon steel, to improve the die hardness, strength and wear resistance, so that the degree of deterioration of toughness of steel has a close relationship.