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采用温挤压技术对40Cr钢进行成形试验,考察了不同温度下温挤压试样的摩擦-磨损行为.通过扫描电镜、能谱仪和X射线衍射仪分析了40Cr钢磨损后表面形貌、化学元素分布和物相组成,讨论了40Cr钢温挤压的磨损机理.结果表明,在挤压温度为550℃时试样晶粒尺寸细小,残余奥氏体含量较高,硬度最高,其磨损性能为最佳;而当温度为650℃和750℃时,晶粒尺寸较粗大,残余奥氏体含量降低.在5N载荷作用下,挤压温度为550℃时,摩擦因数为0.7667;当挤压温度达到650℃,摩擦因数为0.8587,提高了12.01%,磨损性能降低;750℃时,摩擦因数为0.8764,相比550℃提高了14.31%,磨损性能进一步变差;在550、650和750℃时,磨损形式主要为磨粒磨损.
The 40Cr steel was subjected to the forming test with warm extrusion technology and the friction-wear behavior of the 40Cr steel at different temperatures was investigated.The surface morphology of the 40Cr steel after wear was analyzed by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction, Chemical element distribution and phase composition of the 40Cr steel were discussed.The results show that the grain size of the 40Cr steel is small and the residual austenite content is high and the hardness is the highest when the extrusion temperature is 550 ℃. The grain size is coarse and the content of retained austenite is decreased when the temperature is 650 ℃ and 750 ℃, the friction coefficient is 0.7667 when the extrusion temperature is 550 ℃ under the load of 5N, When the temperature is 650 ℃, the friction coefficient is 0.8587, which increases by 12.01% and the wear performance is reduced. The friction coefficient is 0.8764 at 750 ℃, which is 14.31% higher than 550 ℃, ℃, the main form of wear abrasive wear.