Development of Stainless Steel Flux Cored Wire for Surfacing Repairing Hearth Rolls

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 and 0.5wt% heavy rare earth silicon iron.