Magnesium and calcium-containing 45MnVS free machining quenched and tempered steel and manufacturing method thereof

Abstract

The invention provides magnesium and calcium-containing 45MnVS free machining quenched and tempered steel and a manufacturing method thereof. The steel comprises the main components of 0.42% to 0.51% of C, 0.15% to 0.6% of Si, 0.90% to 1.50% of Mn, 0.010% to 0.035% of P, 0.040% to 0.080% of S, 0.06% to 0.13% of V, 0.0005% to 0.008% of Mg, 0.01% to 0.04% of Al, 0.0008% to 0.005% of Ca, and the balance being Fe and unavoidable impurities. According to the magnesium and calcium-containing 45MnVS free machining quenched and tempered steel and the manufacturing method thereof, though adopting converter control smelting, LF+VD magnesium calcium compounded inclusion form treatment modification, M-EMS+F-EMS composite continuous casting and controlled rolling and controlled cooling, and adding a trace amount of magnesium and calcium on the basis of traditional 45MnVS steel, the sulfur-containing inclusion is modified, the material strength index is equivalent to the quenching and tempering condition of No.45 steel, and the calcium-containing 45MnVS free machining quenched and tempered steel has machinability and fatigue resistance better than the 45MnVS steel, and is applicable to parts and structural parts such as automobile connecting rods, crank shafts, knuckle spindles, drive shafts and front axles.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgy, in particular to a non-quenched and tempered steel and a production process thereof, and relates to a free-cutting non-quenched and tempered steel containing Mg-Ca and a manufacturing method thereof. Background technique [0002] Free-cutting non-quenched and tempered steel is a kind of steel that has achieved or approached the mechanical properties of quenched and tempered steel and has easy machinability through microalloying, controlled rolling and controlled cooling, etc. Class high-quality or special quality structural steel. Free-cutting non-quenched and tempered steel is widely used in parts and structural parts such as automotive connecting rods, crankshafts, steering knuckle shafts, drive shafts, front axles, etc., and its consumption is increasing day by day. It is a typical representative of automotive steel and caters to continuous machining The development in the direction o...

AI Technical Summary

Problems solved by technology

The sulfur-containing free-cutting steel produced by traditional electric furnace → LF → continuous casting → controlled rolling and controlled cooling or converter → LF → continuous casting → controlled rolling and controlled cooling and Al deoxidation process has poor purity, uneven composition and temperature, nitrogen and hydrogen High content and Al flocculent oxides are easy to block the nozzle and poor pourability

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