电渣熔铸模具钢/低合金钢双金属平板件组织与性能的研究

Investigation of the structures and properties of the bimetal composite by the Electro-slag Melting and Casting Steel

采用电渣熔铸方法制备Cr12MoV模具钢/40Cr结构钢双金属复合材料,研究了热处理工艺参数对双金属组织和性能的影响。结果表明:采用适当的熔铸工艺可获得界面结合牢固、均匀平整且过渡层适当的双金属平板件。双金属Cr12MoV钢一侧的淬火和回火组织为回火马氏体+网状共晶碳化物+细小粒状二次碳化物+少量残余奥氏体。双金属的最佳热处理工艺为980 ℃淬火+230 ℃回火,其冲击韧度αk 值可达25 J/cm2 以上,工作层硬度HRC≥62。

The bimetal composite consisting of Cr12MoV steel/40Cr steel was fabricated by the electro-slag Melting and casting. The effects of cast and heat treatment technological parameters on the microstructures and properties of the bimetal composite were investigated. The results indicated that the bulk flat plates with the interfaces with firm combining strength and proper thickness of transitional layer were obtained by some technological measures such as the relative moving between electrodes and a crystallizer. The microstructures of Cr12MoV steel in the bimetal composite consists of martensite + network carbide + fine second carbide + austenite after quenching and tempering. The optimizing heat treatment technologies are that the bimetal composite is quenched at 980°C and tempered at 230°C, which impact toughness αx of the bimetal composite can reach more than 25 J/cm2 and hardness (HRC) of the Cr12MoV steel in the bimetal composite is more than 62.