| 引用本文: | 许全军,刘秀国,龚宝明,邓彩艳,王东坡,刘永.USRP处理45钢微观梯度力学性能演变及残余应力分布∗[J].中国表面工程,2021,34(6):151~159 |
| XU Quanjun,LIU Xiuguo,GONG Baoming,DENG Caiyan,WANG Dongpo,LIU Yong.Evolution of Micro-gradient Mechanical Properties and Residual Stress Distribution of 45 Steel by USRP[J].China Surface Engineering,2021,34(6):151~159 |
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| 摘要: |
| 针对材料表层梯度结构力学性能及残余应力分布研究不够深入的问题,对正火态 45 钢进行超声表面滚压加工 (USRP) 处理,在材料表层制备出微观梯度结构,并进行金相、SEM 和 EBSD 分析。 结果表明,根据形变程度将表层微结构分为 3 个区域:强变形区、微变形区和未影响区,厚度最高可达 680 μm。 接着采用应变梯度理论(MSG)修正的仪器化压痕法对试样表层力学性能进行分析,发现试样表层的显微硬度、弹性和塑性变形性能均呈现明显的梯度变化。 最后,采用轮廓法和 X 射线衍射法相结合的方式测量试样表面及内部残余应力分布。 测试结果表明,处理后试样表面形成一定深度的残余压应力场,在距离表面约 700 μm 处压应力峰值仍可达 809. 6 MPa,并且两种测试方法具有较好的一致性。 系统分析了试样表层在微观组织、屈服强度、残余应力分布和塑性流变性能方面出现的明显梯度变化。 |
| 关键词: 表层微结构 超声表面滚压处理 纳米压痕法 轮廓法 残余应力 |
| DOI：10.11933/j.issn.1007-9289.20210825002 |
| 分类号:TG159 |
| 基金项目:国家自然科学基金资助项目(51771135) |
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| Evolution of Micro-gradient Mechanical Properties and Residual Stress Distribution of 45 Steel by USRP |
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XU Quanjun, LIU Xiuguo, GONG Baoming, DENG Caiyan, WANG Dongpo, LIU Yong
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School of Materials Science and Engineering, Tianjin University, Tianjin 300350 , China
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| Abstract: |
| To address the lack of in-depth study on the mechanical properties and residual stress distribution of the gradient structure of the material surface, optical microscope (OM), scanning electron microscope (SEM) and electron back scattering diffraction (EBSD) analyses are carried out on the surface gradient structure of normalized 45 steel obtained by ultrasonic surface rolling process (USRP). The structure is analyzed by optical microscope (OM), scanning electron microscope( SEM) and electron back scattering diffraction (EBSD). Several distinct zones can be identified by the plastic deformation, i. e. strongly plastic distorted, plastic deformed and undeformed areas. The thickness of the plastically deformed area increases with the increase of treatment time, and the maximum thickness of the plastic deformation layer can reach 680 μm. Moreover, the instrumental indentation method based on the strain gradient theory (MSG) is used to determine the gradient mechanical properties of the surface. It is found that the microhardness, elasticity and plastic deformation properties show obvious gradient changes along the surface depth. Finally, the residual distribution along the depth is determined by the contour method and X-ray diffraction, respectively, and very good agreement can be obtained by the two methods. The results show that residual compressive stress field is formed on the surface of the sample after treatment, and the compressive stress peak value can reach 809. 6 MPa at a depth of about 700 μm from the surface. Systematic analysis of the obvious gradient changes in the surface layer of the sample in terms of microstructure, yield strength, residual stress distribution and plastic rheological properties. |
| Key words: surface microstructure USRP nanoindentation method contour method residual stress |
