Production method of steel for medium-carbon sulfur-containing crankshaft

The invention discloses a production method of steel for medium-carbon sulfur-containing crankshafts, and relates to the technical field of metallurgy. According to the method, measures are taken for key procedures of the medium-carbon sulfur-containing steel for the crankshaft produced through the technological process of converter-refining-continuous casting of square billets (350 * 430 mm)-bar rolling, and the method is characterized by comprising the procedures of converter smelting, LF furnace refining, RH vacuum treatment, continuous casting pouring, rolling and slow cooling, and chemical components take a medium-carbon alloy structure as the design basis; a proper amount of N element and Al are added to refine grains, a certain content of S element is added to improve the cutting performance of the material, a specific inclusion improvement method is adopted in the refining process to homogenize sulfide, and inclusion in steel and internal defects of a casting blank are reduced by protecting casting an