【摘要】 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。更多还原

【Abstract】 The effect of minor-alloying elements RE,Al on phase transformation kinetics within 700～560℃ and 380～320℃ and structure properties of bainitic steels was studied.The microstructure consists of well distributed fine bainites,tempering martensites,carbides and a small amount of austenite after forging air cooling.Under microscope the needle appearance of bainite (including martensite)is hardly distinguished.It is a hidden-crystal bainite or thin-needle.The addition of minor alloying element RE does not accelerate pearlite transformation,but it is a little delay the pearlite transformation.It fines microstructure,and improves impact toughness,the addition of minor-alloying element Al accelerates the pearlite transformation and it also fines microstructure and improves impact toughness.The addition of RE and Al elements at same time has additive effect.The effect of minor-alloying elements RE,Al on phase transformation kinetics within 700～560℃ and 380～320℃ and structure properties of bainitic steels was studied.The microstructure consists of well distributed fine bainites,tempering martensites,carbides and a small amount of austenite after forging air cooling.Under microscope the needle appearance of bainite (including martensite)is hardly distinguished.It is a hidden-crystal bainite or thin-needle.The addition of minor alloying element RE does not accelerate pearlite transformation,but it is a little delay the pearlite transformation.It fines microstructure,and improves impact toughness,the addition of minor-alloying element Al accelerates the pearlite transformation and it also fines microstructure and improves impact toughness.The addition of RE and Al elements at same time has additive effect.更多还原