等通道角挤压变形中高碳珠光体钢的组织演变  

Microstructure evolution in a pearlitic structured high carbon steel during equal channel angular pressing

作　　者：郭志强[1] 熊毅[1,2] 何红玉[1] 卢艳君[3] 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南省有色金属材料科学与加工技术重点实验室,河南洛阳471003 [3]广州民航职业技术学院飞机维修工程学院,广东广州510403

出　　处：《材料热处理学报》2013年第8期124-128,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(50801021);河南科技大学人才科学研究基金资助项目(07003);河南省高等学校青年骨干教师资助项目(2011GGJS-070)

摘　　要：在650℃对原始组织为层片状珠光体的T8钢进行Bc路径的多道次等通道角挤压(ECAP)变形,借助SEM、TEM和AFM研究了变形过程中渗碳体片层的演变情况。结果表明:渗碳体片层表现出强烈的塑性变形能力,主要以剪切断裂、扭折、弯曲等变形方式来适应剧烈的塑性变形;四道次温变形后得到晶粒尺度均在亚微米量级的超微细复相组织(α+θ);球化完全的渗碳体颗粒粒径呈双峰分布,从三维的角度表征渗碳体的组织演变及其特性与从二维角度观察分析的结果相吻合。A T8 steel with a fully pearlitic structure was studied by equal channel angular pressing （ECAP） via route Bc at 650 ℃. The microstructure evolution of the cementite lamellae after processing was analyzed by SEM,TEM and atomic force microscopy. The results show that the cementite in the pearlite has higher plastic deformation capability. The severe shear deformation of ECAP is accommodated by bending, shearing and shearing fracture etc in the pearlite lamellae. After four passes, an uhrafine microduplex structure （ferrite ＋ cementite） with a grain size at the sub-micrometer level is observed. The cementite particle size distribution is bimodal. The microstructure evolution of the cementite lamellae is observed in three dimensions and is consistent with the results observed in two dimensions.

关 键 词：等通道角挤压 渗碳体 组织演变 球化 

分 类 号：TG142.21[一般工业技术—材料科学与工程]