何烜坤
,
刘庆锁
,
陆翠敏
,
姜训勇
机械工程材料
采用光学显微镜及透射电子显微镜研究了Fe-0.88C-1.35Si-1.03Cr-0.43Mn 钢在200℃短时等温获得的下贝氏体的显微形貌及其精细结构.结果表明:试验钢在 200℃短时等温可获得宽度几十纳米,而长度在微米数量级的条状下贝氏体,在下贝氏体针内沿纵向存在大体与贝氏体针侧边界垂直且平行排列的位错列;贝氏体针纵向前沿的母相中存在间断的、层片状应变场衬度;下贝氏体相变早期具有马氏体切变相变的特征.
关键词:
下贝氏体
,
位错列
,
应变场
,
亚单元
H.S. Fang and C. Zhang Departmentof Materials Science and Engineering
,
Tsinghua University
,
Beijing 100084
,
China
金属学报(英文版)
The viewpoints aboutthe formation mechanism of bainite are described asfollowing aspects: ①Ultra finestructureof bainitein ferrous and nonferrousalloysis discovered by scanningtunneling microscopy (STM) .②STMstudies discoveredthatthesurface relief of bainiteissubstantiallycomposed of groupsofsmallrelieves which correspond of ultra fineunits,theirsurfacereliefistent shaped.③The frequency and mobility of 3 dimensionalsuperledgesinferrousand nonferrousareproved by TEMand STM.④Thebainitecarbide nucleateinthe ∪ sideof α/γinterfaceand grow toward austenite,thegrowth of carbide and ferrite arecom petitive.⑤STMstudies on surface relief of grain boundary allotriomorph ( GBA) andWidmansttten ferrite( WF) . They aretent shaped.⑥Theformation of bainiteisthroughsympathetic nucleation ledgewisegrowth mechanism .And both processesarecompetitive.⑦3 dimensional morphology of upper bainitetransformscontinuously to lower bainite, and noabruptlychange.
关键词:
bainite
,
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,
null
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