炉底辊堆焊修复用不锈钢药芯焊丝的研制

摘要

研制了5种用于炉底辊堆焊修复用的不锈钢药芯焊丝，分析了堆焊金属的化学成分，观察了其显微组织，并对堆焊金属表面进行了探伤，着重探讨了高碳铬铁和重稀土硅铁加入量对焊丝热裂敏感性的影响。结果表明：向焊丝药粉中单独加入适量高碳铬铁后，堆焊金属组织由单相奥氏体转变为由奥氏体和碳化物组成的两相组织，阻断了凝固过程中的晶间液膜，可防止热裂纹的产生；而适量添加重稀土硅铁亦可达到防止热裂纹的目的，但过量添加反而会增加热裂纹倾向；较佳的加入量（质量分数）为8％的高碳铬铁或3％的高碳铬铁和0．5%重稀土硅铁。%Five types of stainless steel flux cored wires for surfacing repairing hearth roll were developed. The chemical composition of surfacing metal was analyzed, the microstructure was observed and the surfacing metal was flaw detected. The effect of addition of high carbon chromium iron and heavy rare earth on the hot cracking sensitivity was discussed specially. The results show that by adding high carbon chromium iron to the flux, the microstructure of surfacing metal tranformed from single-phase anstenite to microstructure with austenite and carbide, that interrupting the intergranular liquid film during solidification and preventing the hot cracks. Reasonable content of heavy rare earth silicon iron in the flux could also prevent hot cracks. However, excessive addition could play a oppisite role. The reasonable addition were 8wt% high carbon chromium iron or 3wt% high carbon chromium iron and0. 5wt% heavy rare earth silicon iron.