Ultra-high-strength heat-resistant gear bearing steel with ultra-hardened surface layer and preparation method thereof

Abstract

The invention belongs to the technical field of materials, and relates to an ultra-high-strength heat-resistant gear bearing steel with ultra-hardened surface layer and a preparation method thereof. The chemical composition of the steel comprises the following chemical components of, in percentage by mass, 0.08-0.18% of C, 10.0-16.0% of Co, 3.0-8.0% of Ni, 3.0-7.0% of Cr, 3.0-6.0% of Mo, 0.5-2.0%of W, 0.2-1.0% of V, 0-0.1% of Nb, and the balance Fe and impurity elements. According to the method, vacuum induction melting, vacuum induction melting and vacuum arc remelting or vacuum induction melting and electroslag remelting are adopted for smelting. Steel ingots are diffusion annealed and forged into steel products. Steel samples are subjected to preliminary heat treatment, carburization and final heat treatment, the tensile strength of the steel is not less than 1900 MP a, the yield strength is not less than 1600 MP a, and the carburized surface hardness is not less than 850 HV (equivalent to 66 HRC). The method has the advantages that compared with the prior art, the method has higher tensile strength, yield strength and relatively good plasticity, toughness and heat resistance,has excellent surface carburization super-hardening performance and fatigue performance, and achieves good matching of the core super-toughening and surface super-hardening.

Description

technical field [0001] The invention belongs to the technical field of materials, and relates to a super-hardened super-high-strength heat-resistant gear bearing steel on the surface and a preparation method thereof. Background technique [0002] Gears, bearings and transmission shafts are the key components of mechanical transmission systems such as aero-engines, helicopters, high-speed trains, heavy-duty vehicles, and wind power plants. They serve under heavy loads, high speeds, severe state changes, and complex stress conditions. High bearing capacity and good heat and wear resistance, thus ensuring high reliability and durability of transmission components. In order to meet the requirements of heavy-duty, high-speed gears, bearings and drive shafts, the gear bearing steel should have excellent surface superhardening properties, high strength, toughness and heat resistance. [0003] The gear bearing steel of the present invention not only has ultra-high strength and high...

AI Technical Summary

Problems solved by technology

With the development of a new generation of mechanical equipment, higher requirements are put forward for the load-carrying capacity, service life and structural weight reduction of transmission components. The existing gear bearing steel is difficult to meet the requirements due to its low core toughness and surface hardening performance.

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