Steel casting of high-pressure cylinder of coal-fired steam turbine

The utility model discloses a coal-fired steam turbine high-pressure cylinder steel casting which comprises a steel casting cylinder body, a stainless steel inner layer is fixedly arranged on the inner surface of the steel casting cylinder body, a hard alloy reinforcing layer is fixedly arranged on the outer surface of the steel casting cylinder body, and a stainless steel outer layer is fixedly arranged on the outer surface of the hard alloy reinforcing layer. A heat preservation sleeve is detachably arranged on the stainless steel outer layer, and a fireproof aluminum layer, a first heat insulation layer, a second heat insulation layer and a stainless steel outer cover are sequentially arranged on the heat preservation sleeve from inside to outside; the fireproof aluminum layer is fixed on the outer surface of the stainless steel outer layer through a first stainless steel screw; the outer surface of the fireproof aluminum layer is bonded and fixed with the inner surface of the first heat insulation layer;