热变形量对低铬白口铸铁显微组织和冲击性能的影响

Effect of Hot Deformation Reduction on Microstructure and Impact Properties of Low-Chromium White Cast Iron

对低铬白口铸铁进行了不同压下量的980℃热变形,用光学显微镜、X射线衍射仪和扫描电镜等对不同热变形量的白口铸铁进行显微组织和物相分析,用硬度计和冲击试验机测定白口铸铁的力学性能。结果表明:随着变形量的增大,低铬白口铸铁中析出的颗粒状碳化物增多,硬度逐渐减小,冲击韧度逐渐增大;但当变形量为50%时,其组织中会出现显微裂纹。

The low-chromium white cast iron was hot deformed at 980℃with different redutctions.The microstructure and phase of the white cast iron with different hot deformation reductions were studied by using optical microscopy,XRD and SEM.The mechanical properties of the white cast iron were tested by the hardness and impact testing machine.The results show that with the increase of the hot deformation reduction the granular carbides precipitated from the low-chromium white cast iron increased,the hardness decreased and the impact toughness increased.Microcracks occured in the microstructure when the deformation reduction was 50%.