双辊薄带连铸高速钢铸带中碳化物的形成及演变  

Formation and Evolution of Carbides in High Speed Steel Cast-strip Produced by Twin-roll Strip Casting

作　　者：张彩东[1] 丁培道[1] 蒋斌[1] 周守则[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400030

出　　处：《机械工程材料》2008年第11期31-33,52,共4页Materials For Mechanical Engineering

基　　金：高校博士基金资助项目(教技发中心函[2001]156号);重庆市科委重点资助项目(2000-6539)

摘　　要：采用光学显微镜观察了在工业双辊薄带连铸机上制备的M2高速钢铸带中的碳化物,利用二次枝晶间距计算了铸带的凝固速率;并用扫描电镜和透射电镜研究了高温热处理后铸带中亚稳相M2C碳化物的演变情况。结果表明:双辊薄带连铸高速钢工业铸带的凝固速率为1.7×103K.s-1,比实验室铸带的5.4×102K.s-1高一个数量级,远远高于工业铸锭的2×10-1K.s-1;双辊薄带连铸工艺可以细化高速钢铸带中的共晶碳化物,并获得较多的亚稳相M2C碳化物,在高温热处理过程中M2C碳化物与部分奥氏体反应生成稳定相M6C和MC碳化物,使碳化物分布更加均匀弥散。The carbides in M2 high speed steel cast-strip produced by industrial twin-roll castor was studied by means of optical microscopy. The cooling rate of M2 industrial cast-strip was calculated according to the secondary dendrites space. The evolution of metastable phase M2C carbides in M2 cast-strip after heat-treatment was investigated by means of SEM and TEM. The results showed that the cooling rate in industrial twin-roll casting was 1.7 × 10^-3 K·s^-1, faster than that in laboratorial twin-roll casting （5. 4 × 10^-2 K·s^-1） and in industrial casting （2× 10^-1 K·s^-1）. The twirrroll strip casting technology could refine the eutectic carbides in cast-strip and more metastable phase of M2C carbides could be obtained by this technology. The carbides in M2 Cast-strip could be refined and homogenized by the decomposing of metastable phase M2C carbides during heat-treatment.

关 键 词：双辊薄带连铸 高速钢 碳化物 亚稳相 

分 类 号：TG142.4[一般工业技术—材料科学与工程]