Welding process of steel plate for ultra-large-thickness hydrogenation reactor

The invention relates to a welding process of a steel plate for an ultra-large-thickness hydrogenation reactor. The welding process comprises the steps of groove manufacturing, preheating, backing welding, filling welding, postweld heat treatment, nondestructive testing and the like. According to the welding method, the PF-500/US-521H type heat-resistant steel submerged arc welding wire and the welding flux are selected for welding, and a welding joint which is excellent in crack resistance and low-temperature impact toughness and low in tempering embrittlement sensitivity can be obtained. The optimized groove design is adopted, and the effects that the amount of weld metal is minimum, deformation generated by a weldment is small, and the proportion of base metal in weld metal is small are achieved. A submerged-arc welding method is adopted, the preheating temperature and the interlayer temperature are strictly controlled, and reasonable hydrogen elimination treatment and postweld heat treatment are matched,