Medium-carbon medium-silicon niobium microalloyed high-speed wheel steel and wheel preparation method

Abstract

The invention discloses medium-carbon medium-silicon niobium microalloyed high-speed wheel steel and a wheel preparation method, and belongs to the field of railway wheel preparation. Aiming at the problems that in the prior art, high-speed wheel steel is poor in adaptability and low in strength and hardness, the invention provides medium-carbon medium-silicon niobium microalloyed high-speed wheelsteel. The steel comprises the following components in percentage by weight: 0.50%-0.58% of C, 0.50%-0.80% of Si, 0.50%-0.90% of Mn, 0.02%-0.04% of Nb, no greater than 0.015% of P, no greater than 0.015% of S and the balance of Fe and inevitable impurity elements. The niobium element is added into the components of the wheel steel; niobium and carbon are combined to form niobium carbide, the effect of refining pearlite groups is achieved during steel rolling and heat treatment, meanwhile, it is guaranteed that a certain amount of ferrite is separated out, the strength and toughness matching of the wheel steel is improved, the strength and hardness level is improved by 5% or above compared with an ER8 wheel, and the contact fatigue resistance and wear resistance are also improved. According to the preparation method disclosed by the invention, heat treatment is subjected to process optimization, so that the adaptability of the wheel is further improved, and the wheel has relatively high strength and hardness.

Description

technical field

[0001] The invention belongs to the technical field of railway wheel preparation, and more specifically relates to a niobium microalloyed high-speed wheel steel with medium carbon and silicon and a method for preparing the wheel. Background technique

[0002] my country's high-speed railway development has achieved world-renowned achievements, and the key components of high-speed trains have also achieved independent innovation. At present, my country's high-speed wheels are mainly ER8 wheels in the European standard EN13262, which are made of medium-carbon carbon steel and have high fracture toughness (≥70MPa m 1 / 2 ) to ensure service safety. The structure of ER8 wheel is a small amount of discontinuous reticular ferrite + lamellar pearlite, in which ferrite is a soft phase with good toughness and low yield strength, and pearlite has high strength but poor toughness. The matching relationship determines the final performance of the material. The yield str...

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