Q&P钢配分过程中的组织演变  

Microstructural evolution in quenching & partitioning steel during partitioning process

作　　者：庄宝潼[1,2] 唐荻[1] 江海涛[1] 米振莉[1] 

机构地区：[1]北京科技大学高效轧制国家工程研究中心,北京100083 [2]北京航空制造工程研究所,北京100024

出　　处：《北京科技大学学报》2012年第11期1288-1293,共6页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(50804005);中央高校基本科研业务费专项(FRF-TP-11-005B)

摘　　要：利用扫描电镜、透射电镜、X射线衍射和电子探针等研究了0.2C--1.51Si--1.84Mn钢在配分阶段组织的演变情况.配分温度为400℃时,碳在10 s时就可以完成配分,得到残余奥氏体最大体积分数为13.4%.随着配分时间的增长,钢中马氏体发生回火现象,奥氏体发生分解,强度、延伸率降低.当配分时间达到1000 s时,屈服强度、延伸率突然升高.分析认为马氏体回火带来的塑性提高抵消了残余奥氏体量减少引起的塑性降低,并且由于渗碳体和碳化物的析出,变形时阻碍位错的运动,从而提高了屈服强度.通过电子探针分析说明配分阶段发生了碳的扩散,随着配分时间的增长,发生了渗碳体和碳化物的析出,降低了残余奥氏体中碳的含量.Microstructural evolution in 0. 2C-1.51Si-1.84Mn steel during partitioning process was studied by scanning electron microscopy （SEM） , transmission electron microscopy （TEM） , X-ray diffraction （XRD） and electron microprobe analysis （EMPA）. When partitioning at 400 ℃, carbon atoms have redistributed within 10 s, and the volume fraction of retained austenite is 13.4%. When the partitioning time increases, martensite is tempered and austenite decomposes, leading to the decrease of strength and elongation. However, when the partitioning time is 1 000 s, the tensile strength and elongation suddenly increase. The reason is that the elongation loss caused by decomposition of retained austenite is offset by tempered martensite, the precipitation of carbides and cementite impedes dislocation movement, and thus its tensile strength increases. EPMA results show that carbon atoms diffuse during partitio- ning process, and carbides and cementite precipitate when the partitioning time increases, which decreases the content of carbon in retained austenite.

关 键 词：钢热处理 组织演变 奥氏体 马氏体 电子探针分析 

分 类 号：TG142.2[一般工业技术—材料科学与工程]