CrMnTi narrow hardenability strip pinion steels and method of manufacture

Abstract

The invention relates to CrMnTi narrow-hardenability gear steel and a method for manufacturing the same, belonging to the gear steel material and the production process thereof technical field. The chemical composition in percentage by weight of the gear steel is: 0.13-0.23 percent of C, 0.17-0.30 percent of Si, 0.80-1.25 percent of Mn, 0.04-0.10 percent of Ti, 0.90-1.35 percent of Cr, less than or equal to 0.20 percent of Cu, less than or equal to 0.050 percent of S, less than or equal to 0.030 percent of P, less than or equal to 0.05 percent of Mo, less than or equal to 0.25 percent of Ni, [O] less than or equal to 20x10<-6>, [H] less than or equal to 2.5x10<-6>, and the balance being Fe and inevitable impurities. The manufacturing method comprises the following process steps of smelting, continuous casting, rolling and hot rolling, wherein in the step of continuous casting, the superheat degree of a tundish is controlled between 10 and 30 DEG C, and the casting speed is between 0.50 and 0.85 m / min; in the step of rolling, the heating temperature is between 1130 and 1280 DEG C, the start rolling temperature is more than or equal to 1100 DEG C, and the finish rolling temperature is between 850 and 980 DEG C. The gear steel and round steel in the specification between phi 30 and 160 mm can be produced by adopting the manufacturing method. By adopting narrow-composition steel grade design, electric furnace burden structure optimization, electric furnace end point control, grain-refining and banded structure control and other reasonable technological measures, the method effectively realizes hardenability narrowing and other objectives.

Description

technical field [0001] The invention relates to the technical field of metallurgy, belongs to the category of gear steels, and relates to a CrMnTi series narrow hardenability belt gear steel used for manufacturing vehicles, engineering machinery, ships and other traffic and transportation tools, engines, drive axles and its manufacture method. Background technique [0002] Gears are one of the key components in the automobile manufacturing industry. During the operation of transmitting power and changing speed, there are both rolling and sliding between the meshing tooth surfaces, and the roots of the gear teeth are also subjected to pulsating and alternating bending stresses. effect. Affected by overloading and poor road conditions, automotive gears are subjected to large bending loads and instantaneous impact loads. They must not only have good strength, toughness, wear resistance, and be able to withstand impact, bending, and contact stress well, but also require Small ...

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Problems solved by technology

[0012] The present invention aims at the deficiencies of the existing technology and the processing and use requirements of users in the gear production industry, develops and produces high-performance narrow hardenability CrMnTi series gear steels, and mainly solves the problems of uniform steel composition, compact structure, fine grains, narrow end hardenability bands, High purity, good surface quality, and provide a full range of CrMnTi series gear steel grades and manufacturing methods that can meet the individual and differentiated needs of users

This patent solves the problem of gear manufacturing and cost reduction applicable to different working conditions by upgrading and improving the performance and quality of the traditional 20CrMnTiH gear steel

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