Process for quenching-distribution heat treatment on 60Si2CrVA steel spring for trains

Abstract

The invention discloses a process for quenching-distribution heat treatment on 60Si2CrVA steel spring for trains. The process comprises the following steps: polishing a 60Si2CrVA steel round bar with diameter less than or equal to 50mm, and heating the steel round bar to a temperature of between 960 and 1,060 DEG C through an inductive heating mode; then, wrapping the 60Si2CrVA steel round bar into a spring in the temperature state; cooling the wrapped spring to a temperature of between 810 and 900 DEG C, quenching the spring at a temperature of between 130 and 210 DEG C, and keeping constant temperature for 10 to 60 seconds; quickly placing the spring in a medium at a temperature of between 280 and 350 DEG C, maintaining for 50 to 800 seconds, and placing the spring into water or oil for cooling; and tempering the spring at a temperature of between 250 and 470 DEG C for 60 to 120 minutes. The 60Si2CrVA steel spring product has the advantages of high yield limit and fatigue strength, good quenching harden ability, high tensile strength and yield ratio, high toughness and the like.

Description

technical field

[0001] The invention relates to a quenching-distribution heat treatment process for 60Si2CrVA steel spring products used in trains, belonging 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, the locomotive spring products mainly use spring steel such as 60Si2CrVA, 50CrVA, 52CrMoV4. The main pro...