高强韧性冷作模具钢SDC55的Q-P-T工艺及性能  

Q-P-T process and properties of high strength and toughness cold work die steel SDC55

作　　者：邓黎辉[1] 汪宏斌[1] 李绍宏[1] 梁洋杰[1] 闵娜[1] 吴晓春[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《金属热处理》2010年第9期16-19,共4页Heat Treatment of Metals

基　　金：国家"十一五"科技支撑计划项目(2007BAE51B04);上海市重点学科建设项目(S30107)

摘　　要：研究了高强韧冷作模具钢SDC55不同淬火-碳分配-回火(Q-P-T)工艺处理后的组织和性能。使用J-Mat Pro软件辅助计算SDC55的Ms温度。利用相变仪测量材料在碳分配阶段相变情况。对Q-P-T处理之后SDC55的组织进行金相显微镜、扫描电镜研究。利用X射线衍射仪对Q-P-T处理过后的试样进行残留奥氏体测量。结果表明,试验钢经过Q-P-T处理之后与常规的淬火回火的硬度相当,韧性有所提高。经过Q-P-T处理后韧性提高的原因是由于残留奥氏体的稳定性提高。由于SDC55中含有较多的碳化物形成元素,在碳分配阶段有碳化物析出,并且由于马氏体/奥氏体的界面迁移和残留奥氏体的分解,导致经过Q-P-T处理之后残留奥氏体含量有所降低。Quenching-Partitioning-Tempering（Q-P-T）process and mechanical properties of a high strength and toughness cold work die steel SDC55 were investigated.The temperature of Ms was calculated by J-Mat Pro software.The phase change in carbon partitioning stage was studied by the phase-change instrument.The microstructure after Q-P-T process was examined by optical microscopy（OM）,scanning electron microscopy（SEM）.Furthermore,the content of retained austenite in the steel was characterized by means of X-ray diffraction（XRD）.The results show that,comparing with quenching and tempering process,the impact toughness of SDC55 steel treated by Q-P-T is improved and the hardness is not changed,because the stability of retained austenite is increased.The carbide precipitation because of the carbide-forming elements in SDC55 steel,the interfaces migration of martensite/austenite and decomposition of unstable austenite resulted to the content of retained austenite decreased through the partitioning stage.

关 键 词：冷作模具钢 淬火-碳分配-回火(Q-P-T)工艺 微观组织 性能 

分 类 号：TG162.4[金属学及工艺—热处理]