Carbon steel high-speed rail axle with speed of not less than 400 kilometers per hour, and modification method thereof

Abstract

The invention provides a carbon steel high-speed rail axle with a speed of not less than 400 kilometers per hour, and a modification method thereof. The carbon steel high-speed rail axle comprises thefollowing components: not less than 0.30% and not greater than 0.40% of C, not less than 0.15% and not greater than 0.50% of Si, not less than 0.90% and not greater than 1.20% of Mn, trace-0.015% ofP, trace-0.010% of S, not greater than 0.30% of Cr, not greater than 0.08% of Mo, not greater than 0.30% of Cu, not greater than 0.30% of Ni, not greater than 0.06% of V, and the balance Fe and otherinevitable impurities. Modification is carried out via normalizing treatment and laser quenching. Compared with the prior art, the surface hardness of the axle is not less than 620 HV, the surface residual pressure stress exceeds -800 MPa, and the fatigue strength exceeds 480 MPa and is increased by 83% compared with the fatigue strength (263 MPa) of an axle sample which is not subjected to laserquenching.

Description

technical field [0001] The invention belongs to the technical field of high-speed rail axles, in particular to a carbon steel high-speed rail axle with a speed ≥ 400 kilometers per hour and a modification method thereof. Background technique [0002] The axle is a super-large stepped axisymmetric part with a maximum diameter of more than 200mm and a length of up to 2320mm. It forms a wheel set through an interference connection with the wheel and bears the full weight of the rolling stock. It is one of the three key parts of the railway vehicle. . Heavy-duty and high-speed trains are the key development directions of high-speed trains. The axle is the heaviest key moving part of a single body. Improving fatigue performance is the eternal theme of axle steel research and development. [0003] Due to the different national conditions and technical viewpoints of different countries, the axle materials selected are not the same. From the practice of foreign high-speed railway ...

AI Technical Summary

Problems solved by technology

The disadvantage is that the key indicators such as residual stress and fatigue strength on the surface of the axle after laser quenching are not characterized. From the test results of the Rockwell hardness (70-85HR15N, converted into Vickers hardness of about 237-492HV) on the surface of the axle after laser quenching It is estimated that its fatigue performance is low and cannot meet the application requirements of high-speed rail axles with a speed of ≥400 kilometers per hour

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