球化工艺对热轧超高碳钢组织性能的影响  

Effect of Spheroidizing Technology on Microstructure and Mechanical Properties of Hot-rolling Ultra-high Carbon Steel

作　　者：樊亚军[1] 蔺卫平[1] 张占领[1] 朱杰武[1] 柳永宁[1] 许雁[2] 

机构地区：[1]西安交通大学金属材料强度国家重点实验室,陕西西安710049 [2]西北第二民族学院材料科学与工程系,宁夏银川750021

出　　处：《热加工工艺》2006年第20期13-15,18,共4页Hot Working Technology

基　　金：国家自然科学基金资助项目(50571077);陕西省科技攻关基金资助项目(2004KD7-G18)

摘　　要：利用离异共析原理,采用不同的热处理工艺球化热轧超高碳钢。组织观察表明:热轧预处理消除了铸态下晶界网状粗大碳化物,并获得颗粒状碳化物与片状珠光体的混合组织。球化热处理时,奥氏体化温度升高、保温时间延长,碳化物颗粒的间距增大,减缓冷却速率增加碳化物的析出。对球化后超高碳钢进行拉伸力学性能试验,850℃球化后的强度很高(σ0.2=688.71MPa,σb=1005.78MPa),屈强比和伸长率分别为0.69、16.7%。拉伸后的断口形貌分析表明,超高碳钢拉伸过程中裂纹易在大颗粒碳化物处萌生、扩展。Different spheroidizing technologies were applied to the hot-rolling ultra-high carbon steel by DET （divorced eutectoid transformation）. The results show that the hot-rolling pretreatment can remove as-cast reticular coarse carbides at grain boundary, and the mixture microstructure of grained carbides and lamellar pearlite is obtained. When spheroidized, higher austenizating temperature or longer holding time will increase particle spacing of carbides in the steel , more carbides precipitate by reducing cooling rate. The tensile properties indicate that the spheroidized ultra-high carbon steel austenitized by 850℃ has high intensity（σ0.2=688.71MPa, σb=1005.78MPa）, σ0.2/σb and extension rate are 0.69 and 16.7%,respectively.The morphology of fracture surface of the steel was analyzed to show that the crack is able to initiate and spread at the big-grained carbides.

关 键 词：热轧超高碳钢 碳化物 球化 拉伸性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]