304不锈钢超声表面纳米化后的表征  

Characterization of SUS304 with Ultrasonic Nanocrystal Surface Modification

作　　者：曹小建[1] 冯磊磊[1] 张宗培[1] 吴豪[1] 陈晨[1] 郭琳娜[1] 

机构地区：[1]南通大学建筑工程学院,江苏南通226019

出　　处：《南通大学学报（自然科学版）》2014年第3期49-53,共5页Journal of Nantong University(Natural Science Edition)　

基　　金：中国博士后科学基金项目(2014M552355);江苏省高校自然科学研究项目(13KJB130002);南通大学大学生创新训练计划项目(2013082)

摘　　要：利用超声表面纳米化技术(ultrasonic nanocrystal surface modification,UNSM),采用4组静态载荷(70 N,90 N,110 N,130 N)分别在304不锈钢表面获得强塑形变形层,利用光学显微镜、扫描电子显微镜、XRD等研究了由表层到基体的显微特征、残余应力、硬度分布及相组成等.利用有限元方法探讨弹性模量及泊松比同时由表层到基体梯度增加时,弯曲试件内的正应力分布.结果表明:随静态载荷增大,304不锈钢表面强塑性变形层深度增加,表面硬度略有增大,表面残余压应力增大,γ相向α相的转变效应增强;随静荷载增大,试样表面粗糙度由于静荷载较大反而有所增加;表面纳米化处理后,弯曲试样截面最大正应力降低,回转弯曲疲劳条件下能有效提高材料寿命.An ultrasonic nanocrystal surface modification（UNSM） technique at 4 different static loads（70 N, 90 N,110 N, 130 N） was employed to modify the surface structure and properties of SUS304. The microstructure and characterization from surface to matrix was examined using optical microscope, scanning electron microscope, and X-ray diffraction. The influence of reducing elastic modulus and the poisson ratio on the stress distribution were discussed with FEM. The results show that UNSM produces severe plastic deformation（SPD） layers on the surface of specimen.Higher static load induces deeper SPD layer, higher surface compressive residual stress. And, martensitic transformation are enhanced as the static load grows. Oppositely, UNSM technique improves the surface roughness because of the high static loads. With decreasing the elastic modulus and poisson ration, the maximum normal stress shall decrease, which contributes to improving the fatigue life of rotating-bending fatigue specimen.

关 键 词：304不锈钢 超声表面纳米化 X射线衍射 表征 

分 类 号：TG176[金属学及工艺—金属表面处理] TG146.2[金属学及工艺—金属学]