轧制温度对GCr15轴承钢组织性能的影响

Effect of rolling temperature on microstructure and properties of GCr15 bearing steel

在Gleeble-3500热模拟试验机上对GCr15钢试样进行了双道次热压缩,模拟其在预精轧与精轧阶段在不同温度下的组织演变过程。同时设计了特殊GCr15钢试样,可在Gleeble-3500上双道次压缩试验后,再加工成拉伸样,得到相应压缩条件下试样的拉伸性能。采用光学显微镜、扫描电镜(SEM)和拉伸试验机等观察测试了不同压缩温度条件下GCr15钢试样的组织形貌及拉伸性能。结果表明:当精轧温度为800~850℃时,GCr15钢试样可获得珠光体团直径较小、渗碳体片层较细、网状碳化物较少的组织;拉伸试验表明,精轧温度为800℃时,GCr15钢试样的抗拉强度达到最大,温度低于800℃和高于800℃时,抗拉强度逐渐降低。

The GCr15 steel specimens were subjected to double-pass thermal compression on a Gleeble-3500 thermal simulation machine to simulate the process of microstructure evolution at different temperatures in the pre-finish and finish rolling stages. At the same time, a special GCr15 steel specimen was designed, which could be subjected to double-pass compression test on Gleeble-3500, and then processed into a drawing sample to obtain the tensile properties of the sample under the corresponding compression condition. The microstructure and tensile properties of the GCr15 steel specimens under different compression temperatures were measured by means of optical microscope, scanning electron microscopy(SEM) and tensile testing machine. The results show that, when the finish rolling temperature is 800-850 ℃, the GCr15 steel sample can obtain the microstructure of the pearlite group with small diameter, fine layer of cementite and less network carbide. The tensile test shows that the tensile strength of the GCr15 steel specimen is the maximum when the finish rolling temperature is 800 ℃, when the temperature is lower than 800 ℃ and higher than 800 ℃, the tensile strength decreases gradually.