Steel for ball screws and manufacturing method thereof

Abstract

The invention relates to steel for ball screws. The steel for ball screws comprises, by mass: 0.45%-0.60% of C, 0.15-0.40% of Si, 0.90-1.10% of Mn, 0.70-1.20% of Cr, 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, 0.15-0.40% 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, lessthan or equal to 0.003% of Ti, less than or equal to 0.0010% of O, 0.0050-0.0090% of N, 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, lessthan or equal to 0.002% of Pb, and the balance Fe and inevitable impurities. The delivery state of the steel is as follows: high-temperature quenching and tempering are carried out, and the hardness meets 220-280 HBW, and the microscopic structure is of a sorbite and bainite structure, and is subjected to SEP 1927 water immersion high-frequency flaw detection, so that the defect length is requirednot to exceed 5 mm. The manufacturing process comprises the steps of electric furnace or converter, external refining, VD or RH vacuum degassing, continuous casting, continuous casting blank squaringto form an intermediate billet (a square billet), intermediate billet heating and rolling, finishing, quenched-tempered heat treatment (including high temperature quenching and tempering), surface lathing and warehousing.

Description

technical field [0001] The invention relates to the technical field of bar alloy steel, in particular to steel used in processing ball screws and a manufacturing method thereof. Background technique [0002] The ball screw pair is one of the commonly used transmission devices in transmission machinery that uses the rolling of balls between the screw and the nut to simultaneously realize the functions of power transmission and motion conversion. It has the characteristics of high precision, high efficiency and reversibility at the same time. It has become the key executive component in the driving process of various CNC machine tools, automated machinery and machining centers, and is widely used in machinery, nuclear industry, aviation, aerospace and other fields. The rolling screw pair is usually composed of four parts: screw, ball, nut and ball circulation return device. [0003] Ball screw is the most commonly used transmission element in precision machinery. Its main fun...

AI Technical Summary

Problems solved by technology

However, due to the need for carburizing treatment, the production process is complicated and the production cost is high, which is not conducive to popularization

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