Steel alloy

Abstract

A steel alloy comprising:from 0.05 to 0.25 wt.% carbon,from 10 to 14 wt.% chromium,from 1.5 to 4 wt.% molybdenum,from 0.3 to 1.2 wt.% vanadium,from 0.3 to 3 wt.% nickel,from 6 to 11 wt.% cobaltfrom 0.05 to 0.4 wt.% silicon,from 0.1 to 1 wt.% manganese,from 0.02 to 0.06 wt.% niobium,optionally one or more of the following elementsfrom 0 to 2.5 wt.% copperfrom 0 to 0.1 wt.% aluminium,from 0 to 250 ppm nitrogen,from 0 to 30 ppm boron, andthe balance iron, together with any unavoidable impurities,wherein the alloy has a Nieqof greater than 11.5, the Nieqbeing defined by the formula Nieq= Ni + Co +(0.5 * Mn) + (30 * C), in wt.%.

Description

technical field [0001] The invention relates to the fields of steel and bearings. More specifically, the present invention relates to a novel steel alloy, method of forming bearing components, and bearings including such components. Background technique [0002] Bearings are devices that allow constrained relative motion between two components. Rolling element bearings include inner and outer raceways and a plurality of rolling elements (balls or rollers) disposed therebetween. For long-term reliability and performance, it is important that the individual components have a high resistance to rolling fatigue, wear and creep. Bearings used in aerospace applications often need to operate under high loads and extreme temperatures in environments where they may be exposed to moisture. Therefore, these parts need to have an optimal combination of toughness, high temperature performance and corrosion resistance, in addition to excellent surface hardness and core ductility. [0...

AI Technical Summary

Problems solved by technology

This is because an excess of delta-ferrite will impair the toughness of the core microstructure, thereby compromising the toughness and crack resistance of the bearing ring

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