超声滚压18CrNiMo7-6齿轮钢表面变质层性能分析

Performance Analysis of Surface Modification Layer of 18CrNiMo7-6 Gear Steel Treated by Ultrasonic Rolling

研究了18CrNiMo7-6齿轮钢超声滚压后表面变质层的性能和加工工艺。分别运用三维表面形貌测量系统、显微硬度计、超景深三维显微系统和高速大功率X射线残余应力分析仪等工具观察试样加工前后的表面变质层变化,并采用单因素试验分析试验数据,研究超声滚压工艺参数对试样表面变质层的影响。结果表明:经过超声滚压加工,表面粗糙度由未经超声滚压处理的3.003μm减少到0.468μm,显著的加工硬化在该材料表面形成,表面显微硬度从最开始的360.9 HV升高到442.9 HV,升高了22.7%,高硬度层达到了300μm;平整的表面在超声滚压加工后出现;在距离表面40μm处残余压应力形成峰值,其值约为-790.97 MPa。超声滚压技术显著提高了材料的变质层性能。

The performance and processing technology of surface modification layer of 18CrNiMo7-6 gear steel after ultrasonic rolling were studied.The measurement instructions,such as 3D surface topography measurement system,microhardness instrument,super depth of field 3D microscopy system and high power X-ray diffractometer were used respectively,to observe the variation of surface modification layer of the sample.The effects of ultrasonic rolling process parameters on surface modification layer were studied by single factor test.The results showed that after ultrasonic rolling,the surface roughness of the specimen is decreased from the untreated 3.003μm to 0.468μm.Significant work hardening formed on the surface of the material after ultrasonic rolling.Surface microhardness increased by 22.7%from 360.9 HV to 442.9 HV,and the high hardness layer reached 300μm.Flat surface appeared after ultrasonic rolling.The maximum residual compressive stress occured at a distance of 40μm from the surface,which was about-790.97 MPa.Ultrasonic rolling technology significantly improveed the properties of the modification layer.