Method for producing mandrel by utilizing 28NiCrMoV steel as raw material

The invention belongs to the technical field of production of mandrels and relates to a method for producing a mandrel by utilizing 28NiCrMoV steel as a raw material. The mandrel is formed by sorting, refining, forging, rough machining, heat treatment and fine machining. The method comprises the following steps of: when refining, pouring into a steel ingot in an EAF and LF/VD way, demoulding the steel ingot and hot conveying to forge; before forging, controlling heating temperature to 1,150-1,200 DEG C and controlling initial forging temperature to 950-1,150 DEG C and final forging temperature to 750 DEG C in the forging process; and carrying out heat treatment in a normalizing and tempering process way. In the forging process, the feeding amount and the rolling reduction of an oil press are strictly controlled during upsetting; the mandrel is forged and moulded by adopting a precise forging machine of 1,400 tons during moulding; pulling and striking speed and deflection can be strictly controlled in a process of forging of the precise forging machine; and a heat treatment process is carried out in the normalizing and tempering way, thereby achieving the effect of improving strength limit and impact toughness.