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研究了微量稀土 (RE)和Al对贝氏体钢在 70 0～ 560℃和 380～ 32 0℃区域相变动力学及其组织性能的影响。研制的贝氏体钢锻后正火回火获得以贝氏体 /马氏体为主、含碳化物和少量残留奥氏体的组织。在光学显微镜下难以区分贝氏体 (包括马氏体 )的针状组织形貌 ,它是隐晶的或细针状。加入RE元素并不加速珠光体转变 ,而是少许推迟珠光体转变 ,有利于提高钢的淬透性。加入RE使贝氏体钢组织细化 ,冲击韧度提高 ;加入Al加速珠光体转变 ,也使显微组织细化 ,冲击韧度提高。两元素同时加入具有叠加效果。
The effects of rare earth (RE) and Al on the phase transformation kinetics and microstructure of bainitic steel at 70 0-560 ℃ and 380-320 ℃ were studied. Developed bainite steel forging after normalizing tempering to bainite / martensite-based, carbide and a small amount of retained austenite organizations. It is difficult to distinguish the acicular morphology of bainite (including martensite) under an optical microscope, which is cryptocrystalline or fine needle-like. Addition of RE elements does not accelerate the pearlite transformation, but a little delayed pearlite transformation is conducive to improving the hardenability of steel. Addition of RE makes the microstructure of bainitic steel refined and the impact toughness increases. Adding Al accelerates the transformation of pearlite, the microstructure is refined and the impact toughness is improved. Two elements added at the same time with a superposition.