热处理状态对沉淀硬化模具钢动态断裂韧度的影响  

Effect of Heat Treatment Condition on the Dynamic Fracture Toughness of a Precipitation Hardening Steel

作　　者：李明[1] 王永瑞[1] 戎咏华[1] 胡赓祥[1] 陆明炯[1] 杨豪[1] 

机构地区：[1]上海交通大学,上海材料研究所

出　　处：《金属热处理学报》1996年第A00期42-46,共5页

基　　金：上海市青年科技启明星计划;机械工业部共性技术基金

摘　　要：测定了１０Ｎｉ３ＭｎＣｕＡｌ马氏体沉淀硬化型塑料模具用钢在固溶淬火态及不同时间时效后的动态断裂韧度Ｋ＿（１ｄ）。组织为板条状低碳马氏体且条间分布有少量残余奥氏体的固溶态钢，Ｋ＿（１ｄ）值明显高于时效后的Ｋ＿（１ｄ）值，这是由于时效过程中脱溶析出细小弥散的Ａｌ＿３Ｎｉ型沉淀相并对基体产生强烈的应力场所致。试验还表明，此钢的Ｋ＿（１ｄ）冲击速度很敏感，不论是固溶态或时效态，Ｋ＿（１ｄ）都随冲击速度的提高而下降，应用位错动力学理论可对此现象作出解释。The dynamic fracture toughness K_(1d) of a precipitation hardening martensitic steel 10Ni3MnCuAl was tested in the solution-treated state and after agenig for different times. The K_(1d) value of the solution-treated steel having the lath martensite structure with some retained austenite distributed along the lath boundaries is much higher than the K_(1d) of aged steel. This is due to the precipitation of highly dispersed Al_3Ni fine particles and the strong stress field induced by the precipitation process. The tests also showed that the K_(1d) value of this steel is sensitive to the impact velocity. For both solutiontreated and aged specimens, the K_(1d) value decreased rapidly with increasing impact velocity. This phenomenon can be explained by the dynamical dislocation theory.

关 键 词：动态断裂韧度 沉淀 硬化 时效处理 模具钢 

分 类 号：TG161.92[金属学及工艺—热处理]