高钒高速钢/35CrMo复合轧辊界面组织和性能研究

Study on the Microstructure and Property of Roller Interface of High Vanadium High Speed Steel 35CrMo

采用电磁半连续复合铸造法制成高钒高速钢35CrMo复合轧辊,研究了复合界面组织形貌特征和微区成分分布,测试了结合界面的力学性能。结果表明:界面上有厚度为40μm左右扩散层,层内显微组织为珠光体;邻接扩散层的合金钢侧组织为铁素体和珠光体,高速钢侧为马氏体基体上分布着VC颗粒。高速钢和合金钢的显微硬度值分别为700 HV和250 HV,扩散层介于两者之间硬度值为350 HV;冲击韧度值可达到100 J/cm2。该方法制备的复合轧辊界面具有良好的组织特征和力学性能,是冶金结合和扩散结合共同作用的结果。高钒高速钢35CrMo复合界面存在明显扩散层,且界面两侧发生成分扩散。结合区两侧显微硬度差别很大,但在界面处无突变。界面冲击韧度随高钒高速钢面积比的增加快速下降。

The high vanadium high speed steel/35CrMo compound roller was produced by the electromagnetic hemicontinuous compound casting. The composition and structure morphology of bonding interface were analysed, and mechanical property of bonding interface was tested The results show that there is a diffusion layer around interface with thickness of about 40pro. Microstructure in the diffusion layer is perlite, the bordering area is ferrite and perlite, VC particles distribute in the martensitic matrix near the high-speed steel. The microhardness of high-speed steel and 35CrMo are about 700 HV and 250 HV respectively, The microhardness of diffusion layer is 350 HV between high-speed steel and 35CrMo. The impact toughness is 100 J/cm^2. The compound roller interface prepared by this method has good microstructure and mechanical property, which is the combined contribution of metallurgical bonding and diffusion bonding. There is a significant diffusion layer at the interface of high vanadium high speed steel/35CrMo, and composition diffusion on the two sides of the interface. The difference of microhardness is very large at the two sides of bonding area, but there is no sharp change at the interface. The impact toughness at the interface decreases quickly with increase of area ratio of high vanadium high speed steel.