The invention provides a
smelting method of steel for a non-quenched and tempered
crankshaft, the steel for the non-quenched and tempered
crankshaft comprises the following chemical components in percentage by weight: 0.25%-0.50% of C, 0.20%-0.80% of Si, 0.80%-1.80% of Mn, 0.020%-0.060% of S, 0.015%-0.060% of Al, 50-200ppm of N, less than or equal to 0.020% of P and the balance of Fe, inevitable impurities and one or more of V, Ti and Nb, and the total content of V, Ti and Nb is less than or equal to 0.20%. The
smelting method comprises the steps of converter
smelting, LF refining, RH vacuum degassing and
continuous casting. Wherein 1-3 kg / t of
silicon ball deoxidizer, 2-4 kg / t of
lime and 4-8 kg / t of
wollastonite are added during converter smelting and tapping; in the LF refining process, a siliceous deoxidizer with the total amount of 0.5-1.5 kg / t steel is added in batches for
diffusion deoxidation during heating, and meanwhile,
lime with the total amount of 2-6 kg / t steel and
wollastonite with the total amount of 4-9 kg / t steel are added; and in the later stage of LF refining,
sulfur-iron
alloy is added, Al alloying is conducted in the RH vacuum degassing process, and
calcium wires are fed after vacuum breaking. The
casting continuity of the steel for the non-quenched and tempered
crankshaft can be improved, and the content of inclusions can be controlled.