高铬镍合金白口铸铁热疲劳断裂过程的动态观察

Dynamic Observation of Thermal Fatigue Cracking of High Chromium Nickel Alloyed White Cast Irons

用ＨＭ－１００型高温金相显微镜，通过模拟热疲劳的实验方法，动态观察了高铬镍合金白口铸铁热疲劳裂纹的萌生及扩展过程．实验表明：组织为奥氏体加Ｍ２３Ｃ６型碳化物的高铬镍合金白口铸铁热疲劳裂纹主要沿晶界萌生扩展，热疲劳断口为混合型断口．增加含碳量则降低高铬镍合金白口铸铁的热疲劳抗力．

Using HM 100 high temperature microscope,the initiation and propogation of thermal fatigue cracking of high chromium nickel alloyed white cast irons are viewed by means of simulating experiment The results show that the initiation and propogation of thermal fatigue cracking of this kind of iron with austenite and M 23 C 6 are mainly at the interface,and the fracture of the thermal fatigue is of mixed type The thermal fatigue resistance decreases with the increase of content of carbon