【摘要】 用正交试验法研究了等温温度、等温时间、奥氏体化温度和原始组织状态对30CrMnSiNi2A钢组织和性能的影响,提出了可保证该钢在上、中、下限碳量时各项性能均达到技术要求的热处理工艺。对新工艺显著改善钢强韧性的原因作了分析,研究了30CrMnSiNi2A钢在250～280℃温度范围等温淬火后K_IC值出现低谷的现象,并认为在该热处理条件下在马氏体与贝氏体交接面处有大量孪晶马氏体存在以及组织中有许多平行排列的细长等温马氏体板条束出现,是造成K_IC值降低的主要原因。更多还原

【Abstract】 The effect of isothermal temperature, isothermal holding time, austenitizing temperature and original structure on the microstructure and mechanical properties of 30CrMnSiNi2A steel are studied by using orthogonal experimental method. A new heat-treatment process is suggested, which can ensure the carbon content of steel within upper and lower limit to fulfill the technical requirements. The reason for the suggested process of improving the strength and toughness of the steel is discussed. The twin martensite between lath martensite and bainite and the long lath martensite are the main reasons for the decrease of KIC when the steel is isothermally quenched at 240℃-280℃.更多还原