Process for heat-treatment on spring steel product for high-speed heavy-load trains

Abstract

The invention discloses a process for heat-treatment on a spring steel product for high-speed heavy-load trains. The process comprises the following steps: heating spring steel to a temperature of between 960 and 1,100 DEG C; wrapping the steel into a spring; cooling the wrapped spring to a temperature 5 to 50 DEG C lower than Ar1; insulating the spring for 0 to 1 hour, and reheating the wrapped spring to a temperature 5 to 50 DEG C higher than Ac3; and quenching and tempering the spring to produce the spring steel product for the high-speed heavy-load trains. Compared with the prior art, the process has the advantages of high fatigue resistance, tensile strength and yield ratio, enough plasticity and toughness, easily wrapped forming under heat state, good hardenability and the like.

Description

technical field [0001] The invention relates to a heat treatment process for spring steel products used in high-speed and heavy-duty trains, and belongs to the technical field of metal heat treatment. Background technique [0002] Springs for locomotives and trains are very important mechanical parts, which play various functions such as shock absorption, energy storage, connection, and support. Locomotive springs work under alternating stresses such as periodic bending and torsion, and are subjected to dynamic load conditions such as tension, compression, torsion, and impact, and sometimes extremely high short-term sudden loads. Therefore, spring steel must have High fatigue strength, high tensile strength and yield strength ratio, sufficient plasticity and toughness, good surface quality, easy rolling and forming in hot state, good hardenability, etc. At present, spring steel products for locomotives mainly use spring steels such as 60Si2CrVA and 50CrVA. The main heat tr...

AI Technical Summary

Problems solved by technology

After austempering, under the same hardness conditions, compared with ordinary quenching and tempering, it has high toughness and small notch sensitivity, but the yield limit and ...