High-speed axle steel material and heat treatment method thereof

Abstract

The invention discloses a high-speed axle steel material and a heat treatment method thereof. The high-speed axle steel material comprises 0.22 wt%-0.29 wt% of C, 0.17 wt%-0.38 wt% of Si, 0.53 wt%-0.77 wt% of Mn, 0-0.015 wt% of P, 0-0.010 wt% of S, 0.20 wt%-0.27 wt% of Ni, 0.95 wt%-1.15 wt% of Cr, 0-0.15 wt% of Cu, 0.20 wt%-0.29 wt% of Mo, 0.02 wt%-0.05 wt% of V, 0.015 wt%-0.045 wt% of Al, 0.01 wt%-0.03 wt% of Nb, 0-15 PPm of O, 0-1.5 PPm of H and the balance Fe and other inevitable elements. The heat treatment method comprises the following heat treatment requirements that the normalizing heating temperature is 880 DEG C-920 DEG C; the quenching heating temperature is 870 DEG C-900 DEG C; the heat preservation time is 4-9 h; and the tempering heating temperature is 630 DEG C-660 DEG C. According to the high-speed axle steel material, the yield strength, the tensile strength and the impact toughness are higher than those of an ordinary axle LZ50, the grain size grade is higher, the inclusion size is smaller, the component segregation index is lower, and the fatigue limit is 403 MPa or above and is 103 MPa higher than that of the LZ50.

Description

Technical field [0001] The invention relates to a new material for high-speed rail axles and a heat treatment method thereof. Background technique [0002] The development of new materials for high-speed rail axles is proposed in response to the monopoly of foreign axle technology and the continuous increase in demand for domestic and foreign axles. According to my country's "Medium and Long-term Railway Network Planning", high-speed railways have become the main artery of my country's economic operation. At the same time, the country has promoted high-speed railways to overseas markets as one of its industrial development strategies, and its industrialization prospects are broad. However, the domestic high-speed rail axle steel has always been dependent on imports. In order to meet supporting production and realize localization as soon as possible, the research and development of high-speed rail axle steel technology is imminent. [0003] The axle is one of the three key basic pa...

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Problems solved by technology

[0008] 3) Larger component segregation

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