多道次超声纳米表面改性技术对304不锈钢表面完整性的影响研究  

EFFECT OF MULTIPLE ULTRASONIC NANOCRYSTAL SURFACE MODIFICATION ON SURFACE INTEGRITY OF 304 STAINLESS STEEL

作　　者：马云瑞 连阳 李志坤 叶中飞 李阳[2] MA YunRui;LIAN Yang;LI ZhiKun;YE ZhongFei;LI Yang(State Grid Henan Electric Power Research Institute,Zhengzhou 450052,China;School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]国网河南省电力公司电力科学研究院,郑州450052 [2]郑州大学机械与动力工程学院,郑州450001

出　　处：《机械强度》2024年第5期1265-1270,共6页Journal of Mechanical Strength

基　　金：国家自然科学基金项目(51705470);河南省科技厅-河南省重点研发与推广专项(222102220025)资助。

摘　　要：超声纳米表面改性(Ultrasonic Nanocrystal Surface Modification,UNSM)技术可在金属表面制备出表面完整性较好的强化层,该强化层可有效地提高金属材料的力学性能。探讨多道次UNSM技术对304不锈钢表面完整性的影响,同时获得性能优良的表面强化层。利用多道次UNSM技术对304不锈钢试样进行了表面强化处理,在材料表面制备出了不同深度的强化层。利用显微硬度计、X射线残余应力分析仪、三维形貌仪、金相显微镜,测试了试样的硬度梯度、残余应力梯度、组织梯度,以及表面形貌。结果表明,304不锈钢经过多道次UNSM处理后,晶粒尺寸明显细化,强化层的厚度随加工道次的增加而增加;与未处理试样相比较,UNSM处理2次后,试样表面的残余应力从-156 MPa达到-425 MPa,残余压应力深度达到0.7 mm,材料表面显微硬度从185 HV_(0.2)增大到350 HV_(0.2)。研究结果表明,UNSM技术可构筑出较深的强化层,但需要进行工艺优化。The ultrasonic nanocrystal surface modification(UNSM)technique can build a strengthened layer with good surface integrity on the metal surface,and this layer improves the mechanical properties of metals.The effect of multiple UNSM on the surface integrity of 304 stainless steel was investigated,and a good strengthened layer was obtained.The surface of 304 stainless steel sample was strengthened by multiple UNSM technique,and the strengthened layers with different depths were prepared on the surface of the material.The hardness gradient,residual stress gradient,microstructure gradient and surface morphology of the sample were measured by using the microhardness tester,X⁃ray residual stress analyzer,3D morphometer and metallographic microscope.The results show that the grain size of 304 stainless steel is obviously refined after multiple UNSM treatment,and the thickness of the strengthened layer increases with the increase of treatment times.Comparing with the untreated sample,after two times of UNSM treatment,the residual stress on the surface of the sample increased from-156 MPa to-425 MPa,the depth of residual compressive stress reached 0.7 mm,and the surface microhardness increased from 185 HV_(0.2) to 350 HV_(0.2).The results show that the UNSM technology can build a deeper strengthening layer,but it needs to be optimized.

关 键 词：超声纳米表面改性 表面粗糙度 显微硬度 残余应力 强化层 

分 类 号：TG176[金属学及工艺—金属表面处理]