选取具有中等层错能的316L不锈钢进行表面机械研磨处理 (SMAT),制备出纳米结构表层, 用X射线衍射(XRD)和透射电镜(TEM)研究横截面组织的演变过程.晶粒细化机理如下:奥氏体粗晶内部通过位错湮灭和重组形成位错胞;应变量和应变速率的增加诱发了机械孪生,形成了片层状孪晶;孪晶内部通过位错的运动使显微组织逐渐由片层状向等轴状转变,且晶粒尺寸逐渐减小、取向差逐渐增大;最终形成等轴状、取向呈随机分布的纳米晶组织.同时,对层错能对微观变形方式和纳米化行为的影响进行了讨论.
Nanostructured surface layer was synthesized on 316L stainless steel by means of the surface mechanical attrition treatment (SMAT), the microstructural evolution was examined by using XRD and TEM. A grain refinement mechanism was proposed as follows: the dislocations in the austenite grains annihilate and recombine to form dislocation cells; the increment of strain and strain rate induces mechanical twinning, and lamellar microstructures form; the microstructures translate gradually from lamellar to equiaxed by means of the development of the dislocations in the twins, accompanying by the reduction of grain size and the increment of misorientations; finally, nano--scale grains with equiaxed shape and random crystallographic orientations form. Besides, the effects of staking fault energy on the deformation and grain refinement behaviors were discussed.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%