奥氏体化温度对51CrV4钢淬火组织和性能的影响

为了找出51CrV4钢最佳的奥氏体化温度和最佳的综合力学性能,研究了奥氏体化温度对51CrV4钢淬火组织和性能的影响。试验结果表明,随着奥氏体化温度的升高,奥氏体晶粒逐渐长大,淬火后组织硬度呈先增大后减少的趋势,经460℃回火后的强度先增大后减小;当奥氏体化温度为880℃时,奥氏体晶粒细小均匀,得到的马氏体组织致密,强度和硬度均达到最大值;当奥氏体化温度达到910℃时,奥氏体晶粒粗大,而且试验钢出现明显的脱碳现象,强度、硬度和塑性明显下降。研究表明,在实现完全奥氏体化前提下,为保证晶粒均匀且不出现脱碳现象,51CrV4钢获得良好性能的最佳淬火温度为880℃。

Effect of austenitizing temperature on quenching microstructure and properties of 51CrV4 steel

In order to find out the optimum austenitizing temperature and the best comprehensive mechanical properties of 51CrV4 steel，the effects of austenitizing temperature on the quenching microstructure and properties of 51CrV4 steel were studied. The results show that with the increase of austenitizing temperature，the austenite grains gradually grow and the hardness increases first and then decreases，and the strength after tempering at 460 ℃ increases first and then decreases. When the austenitizing temperature is 880 ℃，the austenite grains are fine and uniform，the martensite structure is dense，the strength and hardness reach maximum. When the austenitizing temperature reaches 910 ℃，the decarburization phenomenon is obvious，and the strength，hardness and plasticity of the test steel decrease obviously. The research shows that in order to ensure uniform grain size and no decarburization under the premise of complete austenitization，the best austenitizing temperature of 51CrV4 steel for good performance is 880 ℃.