Steel for heavy loading gear

Abstract

This invention belongs to the alloy, it especially relates to the steel of gear which is strictly demanded on carburize quenching deformation and can bear on the heavy load. The specific chemical ingredient of the steel is as follows: C 0.17-0.25%, Si 0.05-0.15%, Mn 0.2-0.5%, P<=0.015%, S 0.002%-0.01%, Cr 1.4-2.5%, Ni 1.5-4.0%, Mo 0.1-0.8%, Nb 0.03-0.15%, RE 0.001-0.05%, Al 0.015-0.06%, [N] 0.005-003%, [O]<=0.0015%, the other is Fe and inevitable impurity, it also contains V which is less than 0.2%. This invention is high strength of extension, high ballistic work, low carburize quenching deformation and easy to prepare, contrasting to the existing technology.

Description

technical field [0001] The invention belongs to the field of alloy steels, in particular to steels for gears that have strict requirements on carburizing, quenching and deformation and can bear heavy loads. Background technique [0002] As vehicle engine power increases, the transmission system is required to be able to withstand higher loads. At the same time, in order to increase the power density (output power per unit volume), the volume of the transmission system is required to be reduced, thus putting forward higher requirements for the load-carrying capacity of the gears. In order to improve the bearing capacity of the gear, the gear material often adopts heavy-duty gear steel with high alloy element content, such as 20Cr2Ni4 and 20CrNi2Mo. However, these heavy-duty gear steels have the disadvantages of large carburizing and quenching deformation, which often lead to problems such as difficult subsequent processing of the gears, uneven thickness of the infiltrated la...

AI Technical Summary

Problems solved by technology

However, Nb microalloyed heavy-duty gear steel and its research on carburizing and quenching deformation control have not been reported so far.