Large-specification long-service-life high-carbon bearing steel bar and preparation method thereof

Abstract

The invention provides a large-specification long-service-life high-carbon bearing steel bar and a preparation method thereof, and belongs to the field of bearing steel. The large-specification long-service-life high-carbon bearing steel bar comprises the following chemical components: 0.93 to 1.05 wt% of C, 1.20 to 1.80 wt% of Cr, 0.02 to 0.15 wt% of Mo, 0.02 to 0.15 wt% of Nb, 0.02 to 0.15 wt% of V, 0.02 to 0.15 wt% of Zr, and the balance of iron and other inevitable impurities, wherein the total amount of Nb, V, Mo and Zr is required to be greater than or equal to 0.05 wt% and less than or equal to 0.30 wt%. The bearing steel is subjected to Nb, V, Mo and Zr microalloying addition, an original austenite structure and the carbide size are greatly refined, the contact fatigue life of the large-specification bearing steel is greatly prolonged, and the requirements of a large bearing for the quality and the life of a large-specification bearing steel bar are met.

Description

technical field [0001] The invention relates to the technical field of bearing steel, in particular to a large-scale long-life high-carbon bearing steel bar and a preparation method thereof. Background technique [0002] High-carbon bearing steel is the main material for manufacturing bearings, accounting for more than 80% of the production and sales of bearing steel, and is an indispensable key basic material for manufacturing bearings. However, due to the fact that the fatigue life of traditional bearing steel decreases significantly with the increase in the size and specification of the bearing steel, especially when the specification of the bearing steel bar exceeds 60mm, the contact fatigue life of the bearing steel decreases exponentially. In order to ensure the improvement of bearing life and high reliability, domestic and foreign countries only put forward metallurgical quality requirements for small and medium-sized bars, but for bearing steel bars with a diameter o...

AI Technical Summary

Problems solved by technology

However, due to the fact that the fatigue life of traditional bearing steel is greatly reduced with the increase of the size of the bearing steel, especially when the size of the bearing steel bar exceeds 60mm, the contact fatigue life of the bearing steel is doubled.

In order to ensure the improvement of bearing life and high reliability, the metallurgical quality requirements are only put forward for small and medium-sized bars at home and abroad, but the quality and life requirements cannot be guaranteed for bearing steel bars with a diameter of more than 60mm.

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