Sensitivity analysis of the process parameters of the composite process of submerged arc surfacing and laser cladding

In steel industry, the descaling rolls is subject to the long-term high-pressure water erosion, dynamic impact, strong wear, and high temperature, which is prone to wear and corrosion failure affecting the continuous production of rolling steel. Submerged arc surfacing with flux cored wire is an important method for strengthening and repairing the surface of descaling rolls. It is capable of repairing the surface of descaling rolls in large sizes. Laser cladding reinforcement on the basis of submerged arc surfacing layer can realize the complementary advantages of the two reinforcement processes. In turn, the online service life of the descaling roller is improved. This paper establishes a multi-field coupled three-dimensional numerical model of the composite process of submerged arc surfacing and laser cladding of descaling rolls. The transient evolution laws of temperature field, stress field, and phase change field during the composite process were calculated and revealed. Material science microscopic characterization experiments are conducted on the composite reinforced layer of submerged arc surfacing and laser cladding. On this basis, the response surface model between laser power, spot diameter, scanning speed, powder feeding rate, and laser melting temperature and temperature gradient under the composite process was established based on the response surface method. The sensitivity of the process parameters to the effect of temperature and temperature gradient was analyzed by using the Monte Carlo method with multiple sampling calculations. The results show that it is feasible to realize the reinforced repair of the descaling rolls by the combination of submerged arc surfacing and laser cladding process. The maximum temperature of the surfacing process reaches 2100 K, which is lower than the maximum temperature of laser cladding 2500 K. The maximum stress of the two processes is nearly 600 MPa. 97% of the austenite is transformed into martensite during the surfacing process. The spot diameter (C2) has the greatest influence on the laser melting temperature (T) and the melting temperature gradient (TG) under the composite process. This study can provide theoretical guidance for the compounding of the two processes, which has important practical significance and application value.