论文部分内容阅读
利用自制的自约束型热疲劳试验机、光学显微镜及电子扫描显微镜研究了碳化物类型不同的４种合金白口铸铁的热疲劳行为。结果表明：具有Ｍ７Ｃ３型碳化物的１８Ｃｒ２Ｗ及１５Ｃｒ３Ｍｏ合金铸铁的热疲劳抗力最高，而具有Ｍ６Ｃ型碳化物的２５Ｗ４Ｃｒ及具有Ｍ３Ｃ型碳化物的３Ｃｒ合金铸铁的热疲劳抗力均较低；碳化物是热疲劳裂纹扩展的主要通道，热疲劳裂纹长大通过主裂纹与其前沿碳化物中形成的微裂纹之间“桥接”方式进行，热疲劳断口主要为解理断口。
The thermal fatigue behavior of four alloyed white cast irons with different carbide types was studied by self-restraining thermal fatigue tester, optical microscope and scanning electron microscope. The results show that the thermal fatigue resistance of 18Cr2W and 15Cr3Mo alloy cast irons with M7C3 carbides is the highest, while the thermal fatigue resistance of 25W4Cr with M6C carbides and 3Cr alloy cast iron with M3C carbides is low. The carbides are hot The main channel of fatigue crack growth, thermal fatigue crack growth by the main crack and the formation of micro-cracks in the front carbide between the “bridge” way, thermal fatigue fracture mainly cleavage fracture.