【摘要】 对淬火开裂的 5CrMnMo钢大型热锻模进行了金相组织、硬度及断口分析。结果表明 ,淬火加热温度过高 ,加热时间过长 ,导致组织粗大 ;同时淬火冷却终冷温度过低以及未及时回火 ,导致过高的淬火应力 ,使锻模表面出现淬火开裂。建议改进热处理工艺以减小淬火应力更多还原

【Abstract】 The quenching crack of 5CrMnMo steel was investigated through metallograph analysis,hardness test and fracture analysis.The results show that the over-high austenizing temperature and over-long holding time promote growth of the origin austenite grains of the steel,and in the same time the over-low temperature finishing quenching as well as not being tempered in time induces a high quenching stress and bring quenching crack.It was suggested that the heat treatment process be improved through decreasing the austenizing temperature,adding a pre-cooling process, controlling the finishing quenching temperature above 250℃, and tempering in time to decrease quenching stress and prevent the hot working dies from quench-cracking.更多还原