Alloy structure steel 42CrMo slab and production method thereof

Abstract

The invention relates to an alloy structure steel 42CrMo slab and a production method thereof. The method comprises the following steps: (1) charging molten iron containing less than or equal to 0.030% of S, less than or equal to 0.120% of P and less than or equal to 0.85% of Si into a furnace; (2) smelting steel rods containing more than or equal to 0.10% of C and less than or equal to 0.008% of P in the converter at the temperature of 1650-1680 DEG C; (3) performing LF (low frequency) refining and adjusting the target values of the components, so that C is 0.41-0.43% of C, Si is 0.23-0.27%, Mn is 0.58-0.62%, S is less than or equal to 0.010%, P is less than or equal to 0.015%, Cr is 0.92-0.98%, Mo is 0.17-0.19%, Cu is less than or equal to 0.20% of Cu and Ni is less than or equal to 0.30%, wherein the discharge temperature of molten steel is 1560+45 DEG C in a first furnace and 1550+45 DEG C in a continuous casting furnace; (4) performing VD (vacuum degassing) refining under the vacuum of less than or equal to 67Pa for 15 minutes, meanwhile, performing weak argon blowing stirring of 0.15-0.20MPa, feeding 140-150m of CaSi wire with the diameter of phi13mm after breaking, and then performing weak argon blowing for more than or equal to 10 minutes, wherein the discharge temperature is 1560+ / -5 DEG C in the first furnace and 1550+ / -5 DEG C in the continuous casting furnace; and (5) performing continuous casting: controlling the water distribution of each secondary cooling zone of a slab caster by adopting a primary water meter, wherein the light pressing interval fs is 0.45-0.95, the distribution coefficients are shown in table 2, and the pressing quantity is 3.8mm. The method meets the production requirements of large-section 42CrMo slabs.

Description

technical field

[0001] The invention belongs to the field of converter metallurgy, and particularly provides an alloy structural steel 42CrMo slab and a production method thereof. Background technique

[0002] 42CrMo alloy structural steel is mainly used to make locomotive traction gears, supercharger transmission gears, rear axles, engine cylinders, oil deep well drill pipe joints and fishing tools and other important parts of machinery, which require high mechanical properties , such as good forging, stamping and cutting performance, but also the ability to withstand the combined effects of various loads such as tension, compression, shear, torsion, bending and forging under service conditions. Therefore, in terms of metallurgical quality, very strict requirements are placed on the chemical composition, internal and surface quality of the steel.

[0003] 42CrMo steel belongs to the Cr-Mo steel series in alloy steel. The GBT3077-1999 alloy structural steel standard specifi...

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