Gear shaft steel manufacturing method capable of achieving direct cold forging

Abstract

The invention relates to a gear shaft steel manufacturing method capable of achieving direct cold forging. The gear shaft steel manufacturing method capable of achieving direct cold forging comprisesthe following steps of (1) smelting: the components of molten steel include 0.15-0.45% of C, 0.35% or less of Si, 0.60-1.40% of Mn, 0.030% or less of P, 0.030% of S, 0.60-1.40% of Cr, and the balanceFe and inevitable impurity elements; (2) pouring into a square blank; (3) rolling: the square blank is heated before rolling to be austenitized, is discharged out of a furnace, and is descaled, the surface layer of the hot blank is cleaned, the cleaning thickness is 0.5-4 mm, then single-phase area rolling is carried out by adopting 14 two-roller rolling mills and 5 three-roller rolling mills, controlled cooling is carried out in the rolling process, water cooling is carried out respectively after intermediate rolling, pre-finish rolling and finish rolling, the final rolling temperature is 770-850 DEG C, after finish roller is completed, the blank is rapidly cooled to the temperature of 750-830 DEG C of a cooling bed, and the stability of austenite before transformation is lowered; and (4)cooling: the blank is cooled in a blowing mode on the cooling bed, the average cooling speed is controlled to be 45-70 DEG C / min, the final cooling temperature is 300-450 DEG C, the material is air-cooled to the room temperature after the final cooling, and the microstructure of ferrite and pearlite is obtained.

Description

technical field [0001] The invention relates to a gear shaft steel that can be directly cold forged and a manufacturing method thereof, that is, to a gear shaft steel rolled material that is free of heat treatment before cold forging and a manufacturing method thereof. Background technique [0002] Gearboxes are widely used in industry, as long as there is power transmission, it will be applied to gearboxes. Taking passenger cars as an example, my country produces more than 25 million passenger car gearboxes every year. One end of the gearbox inputs power through the input shaft, changes the rotational speed through gears of different modulus, and outputs power through the output shaft. Both the input shaft and the output shaft are called pinion shafts. At present, the gear shaft or gear forming methods in the gear industry are divided into hot forging, warm forging and cold forging. Cold forging has become the development trend of the industry because of its advantages s...

AI Technical Summary

Problems solved by technology

Every time the material undergoes a heat treatment, it will increase the processing cycle, increase energy consumption, and increase production costs

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