Research on microstructure and properties of 3D plasma spray welding repair layer of continuous casting segmented rollers

In this paper, the Fe-Cr-Ni-Si powder was used in a 3D plasma spray welding machine to perform spray welding repair tests on continuous casting segmented rollers for service life improvement. The phase composition, hardness distribution, abrasion resistance and thermal stability of the spray welding layer were analyzed. Results indicated that the spray welding layer produced by 160 A welding current was more uniform and was with finer organization. The main phase zone was a single gamma-Fe and the fusion zone was metallurgically combined with the base metal in a planar grain manner. The hardness of the spray welding layer was the maximum when the welding current was 160 A. The abrasion resistance for each position of the spray welding layer was uniform. The gamma-Fe phase zone decreased and the alpha-Fe phase zone increased with reduction of average hardness after the thermal stability test. In industrial tests, the optimum spray welding parameters were verified and the service life of the continuous casting segmented rollers with spray welding was 2 longer than rollers using surfacing welding process.