42CrMo连铸辊堆焊层的组织结构与性能演变规律

Microstructure and Property Evolutions of Welding Layer on 42CrMo Continuous Casting Roller

采用埋弧堆焊工艺对42CrMo连铸辊的表面进行1层430合金和2层414N合金焊材堆焊。通过堆焊层的成分分析、组织观察和维氏硬度测量,计算合金元素的稀释率和烧损率,研究连铸辊堆焊层的组织演变、合金成分分布与硬度之间的关系。结果表明:430合金焊丝堆焊、第1层414N合金焊丝堆焊和第2层414N合金焊丝堆焊的稀释率分别为27.3%,22.3%和12.5%,Cr元素的烧损率分别为1.17%,1.55%和0.82%;堆焊42CrMo连铸辊沿径向由心部到硬面层可分为42CrMo基体、热影响区、过渡层、430堆焊层、414N堆焊内层和414N堆焊外层的结构;42CrMo连铸辊经埋弧堆焊后可获得厚度约3 mm、成分适中、硬度均匀的硬面层,硬面层组织为细小的板条马氏体。

The 42CrMo continuous casting roller was surfacing with one layer of 430 alloy and two layers of 414 N alloy by submerged arc overlay welding process. By composition analysis, microstructure observation and Vickers hardness measurement of the welding layer, the dilution ratio and burning loss rate of the alloy elements were calculated, and the relationship between microstructure evolution, alloy composition distribution and hardness of welding layer on the continuous casting roller was studied. The results show that the dilution ratio of alloy 430, the first layer of 414N alloy wire and the second layer of 414N alloy wire is 27.3%, 22.3% and 12.5% respectively, and the burning loss rate of Cr element is 1.17%, 1.55% and 0.82%, respectively. From the heart to the surface, the structure of overlay welded 42CrMo continuous casting roller can be divided into 42CrMo matrix, heat affected zone, transition layer, 430 welding layer, 414N inner layer and 414N outer layer. After multi-layer surfacing, a hard surface layer with a thickness of about 3 mm, moderate composition and uniform hardness can be obtained,and the microstructure of the hard surface layer is fine lath martensite.