W9Mo3Cr4V/45钢复合轧辊的液 固结合界面

 采用重力铸造液 固结合的方法对高速钢复合轧辊结合界面进行了研究，并对切取的小试样进行了完全退火、高温焠火+3次550 ℃×1 h回火处理。利用金相显微镜、扫描电镜、能谱分析、X射线衍射仪以及显微硬度计对试样进行了金相组织观察、结合面附近合金成分线扫描、组织成分能谱分析、显微硬度测试和X射线衍射相分析。结果表明：在辊芯45号钢表面电磁感应预热到1 270~1 300 ℃，外层W9Mo3Cr4V高速钢钢液浇铸温度为1 550~1 600 ℃的情况下，两者之间以熔合扩散方式形成了牢固的冶金结合；在铸态下结合界面宽度为40~50 μm，碳及合金元素明显向45号钢侧扩散，通过退火及淬回火处理后，高速钢中的碳及合金元素向45号钢侧进一步扩散，结合界面宽度扩大了100 μm左右，45号钢侧得到细片状索氏体组织，高速钢侧为回火马氏体+残余奥氏体+碳化物组织。

Liquid-Solid Bonded Interface of W9Mo3Cr4V/45 Steel Composite Roll

The microstructure of interface of high speed steel composite roll was studied by gravity casting liquid solid bonding method. At the same time, heat treatment such as full annealing, high temperature quenching and triple tempering of 550 ℃×1 h was performed for the small samples. Microstructure observation, composition analysis of transition zone interfaces of transition zone line scanning, composition analysis of carbides and matrix, X ray diffraction analysis and hardness measurement were conducted. The results indicate that the metallurgy combination between core and shell steel is formed under the condition of the preheating temperature ranging from 1 270 to 1 300 ℃ for core surface by electromagnetic induction heating and casting temperature ranging from 1 550 to 1 600 ℃ for shell steel, the combination mechanism is fusion and diffusing action and interface width is about 45-50 μm and 100 μm under casting condition and after heat treatment, respectively. At the same time, C and other alloy elements diffuse from W9Mo3Cr4V to 45# steel. After heat treatment, the microstructure is lamellar sorbite in 45# steel zone and tempered martensite+residual austenite+carbide in high speed steel.