Steel for inner raceway of constant velocity universal joint and production method thereof

Abstract

The invention discloses steel for an inner raceway of a constant velocity universal joint and a production method thereof. The steel comprises, by weight, 0.15-0.25% of C, 0.01-0.15% of Si, 0.25-0.75% of Mn, 0.80-1.30% of Cr, 0.001-0.003% of B, 0.010-0.040% of Ti, less than or equal to 0.015% of S, less than or equal to 0.025% of P, less than or equal to 0.25% of Ni, less than or equal to 0.20% of Mo, less than or equal to 0.30% of Cu, less than or equal to 0.05% of Al, less than or equal to 0.0010% of Ca, less than or equal to 0.0010% of O, less than or equal to 0.04% of As, less than or equal to 0.03% of Sn, less than or equal to 0.005% of Sb, less than or equal to 0.002% of Pb and the balance Fe and inevitable impurities. The production process comprises the steps of carrying out primary smelting, carrying out refining, carrying out vacuum degassing, carrying out continuous casting, carrying out continuous rolling, carrying out annealing and carrying out finishing. The hardness of the steel is less than or equal to 80HRB; the microscopic structure is ferrite and pearlite; the austenite grain size of the steel is greater than or equal to 6 grade; the banded structure of the steel is graded according to GB / T 13299 and does not exceed 2.0 grade. The hardenability of the tail end of the steel is evaluated according to a GB / T 225 method, and the hardenability of the J5 point is 36-44 HRC, and the hardenability of the J13 point is 24-32 HRC. The steel for the inner raceway of the constant velocity universal joint belongs to novel carburized steel for a universal joint inner raceway, and meets the hardenability, wear resistance and cold forging performance of the steel for the universal joint inner raceway.

Description

Technical field [0001] The present invention belongs to the field of special steel smelting technology, and specifically, a carbon steel and production method of a equation universal section (star sleeve). Background technique [0002] The universal joint is an important component of the automobile transmission system. In the automobile transmission system and other system, the universal transmission must be employed in order to achieve the power transfer between the shafts that intersect or relatively locally changed. At present, the isometric universal joint commonly used on the car is a cage of universal joints, and the role of the cage cage is to transfer the power of the engine from the transmission to two front wheels, and drive the car to travel at high speed. It mainly extends the main parts of the outer roller (spherical shell), the inner roller (star sleeve), the holder (cage), and steel balls. Due to the remaining driving force torque, the load is high, the transmissio...

AI Technical Summary

Problems solved by technology

[0006] The current 20CrNiMo steel has high alloy content and high production cost, and because of the high alloy content, the original structure of hot-rolled bars often has bainite structure in addition to ferrite + pearlite, which has high hardness and poor plasticity. for cold forging

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