摘要
目的揭示深冷处理后磨削加工对变质层特性、服役性能的影响规律。方法以GCr15轴承钢为研究对象,分别进行淬火+回火(QT)、淬火+回火+深冷(QTC)、淬火+深冷+回火(QCT)等3种处理,采用不同磨削深度和工件进给速度对3种试样进行磨削加工,并对磨削加工表面进行表征和服役性能测试。结果在较低磨削深度下,深冷处理试样的表面粗糙度显著低于QT处理试样,3种不同处理试样的白层厚度均随着磨削深度的增加而递增,其中QCT处理试样的白层厚度最大。QTC和QCT处理试样在磨削加工过程中发生残余奥氏体向马氏体的相变,变质层内碳元素呈局部富集。深冷处理试样的黏着磨损程度显著降低,QTC、QCT处理试样的磨损率相较于QT处理试样降低了30%~50%。经深冷处理的磨削加工试样的自腐蚀电流密度显著降低,其耐腐蚀性能显著提高。结论深冷处理通过调控磨削过程中的热-力耦合效应,降低了表面粗糙度。在深冷处理后进行磨削加工,变质层白层组织通过抑制磨粒嵌入和裂纹扩展,可显著提高试样的表面硬度,有效提升了磨削加工表面的耐磨损和耐腐蚀性能。
The work aims to reveal the influence law of grinding processing after cryogenic treatment on the characteristics and service performance of the metamorphic layer.Taking GCr15 bearing steel as the research object,three different process treatments were carried out respectively,namely quenching+tempering(QT),quenching+tempering+cryogenic(QTC),and quenching+cryogenic+tempering(QCT).Different grinding depths and workpiece feed rates were adopted to grind the three specimens.The surface roughness and hardness of the grinding process were measured,and the surface cracks and burn defects were observed.The thickness of the white layer of the grinding metamorphic layer were measured to detect the phase transformation from residual austenite to martensite,and observe the distribution of carbon elements within the metamorphic layer.The wear resistance and corrosion resistance of the grinding surface were evaluated through friction and wear tests and electrochemical corrosion tests.The surface roughness of the cryogenic treated specimens was significantly lower than that of the QT treated specimens at a lower grinding depth.A larger grinding depth was prone to cause surface cracks and burn defects.The thickness of the white layer of the three different treated specimens all increased with the increase of grinding depth,among which the thickness of the white layer of the QCT treated specimens was the largest.During the grinding process of the QTC and QCT treated specimens,a phase transformation from residual austenite to martensite occurred,and the carbon element in the deteriorated layer was locally enriched.Grinding parameters(grinding depth,feed rate)affected the microhardness distribution of the subsurface layer through the thermomechanical coupling effect.The hardness gradient change of the cryogenic treated specimens was more uniform than that of the QT treated specimens,and the surface hardness of the QTC and QCT treated specimens was significantly higher than that of the QT treated specimens.The results of the friction and wear test show that the average friction coefficient of the cryogenic treated specimens is lower than that of the QT treated specimens,the degree of adhesive wear is significantly reduced,and the wear volume and wear depth of the QTC and QCT treated specimens are 30%to 50%lower than those of the QT treated specimens.Electrochemical tests show that the self-corrosion current density of the grinding processing specimens treated by deep cryogenic therapy is significantly reduced,and the corrosion resistance is significantly improved.Deep cryogenic treatment reduces surface roughness and inhibits crack and burn defects by regulating the thermo-force coupling effect during the grinding process.The QCT treated specimens have the maximum thickness of the white layer due to the microstructure adjustment after tempering after deep cryogenic treatment.The residual austenite transformation and carbon element enrichment in the QTC and QCT treated specimens can significantly improve the microhardness of the processed surface.After deep cryogenic treatment and grinding processing,the white layer structure within the deteriorated layer effectively enhances the wear resistance and corrosion resistance of the ground surface by inhibiting the embedding of abrasive grains and crack propagation.
作者
王利虎
冯硕
蔡圣阳
李娜
乔阳
刘国梁
王相宇
WANG Lihu;FENG Shuo;CAI Shengyang;LI Na;QIAO Yang;LIU Guoliang;WANG Xiangyu(School of Mechanical Engineering,University of Jinan,Jinan 250022,China;Shandong UXG Bearing Manufacturing Co.,Ltd.,Shandong Liaocheng 252665,China;School of Intelligent Manufacturing and Control Engineering,Qilu Institute of Technology,Jinan 250200,China;School of Mechanical and Automotive Engineering,Qingdao University of Technology,Shandong Qingdao 266520,China)
出处
《表面技术》
北大核心
2025年第23期238-252,共15页
Surface Technology
基金
国家自然科学基金(52375446)
山东省重点研发计划(2024JMRH0307)
山东省高等学校“青创团队计划”(2023KJ110)。
关键词
深冷处理
磨削加工
变质层
服役性能
白层
cryogenic treatment
grinding processing
metamorphic layer
service performance
white layer
