Breaking-preventing knuckle spindle and thermal treatment method thereof

Abstract

The invention discloses a breaking-preventing knuckle spindle which is made of a material 40Cr, and also discloses a thermal treatment method of the breaking-preventing knuckle spindle, which comprises the following steps of: thermal refining: quenching the knuckle spindle firstly, and then tempering at high temperature; and ultrasonic frequency thermal treatment: placing the thermally refined knuckle spindle into an ultrasonic frequency thermal treatment device for ultrasonic frequency thermal treatment to ensure that the surface of the knuckle spindle has a certain hardening layer depth. Through thermal refining, the invention can ensure that the hardness of the knuckle spindle reaches HRC26-31 and the core metallographic structure reaches 1-6 level of a tempered sorbite, thereby ensuring that the comprehensive mechanical property of the knuckle spindle is strengthened, the hardness reaches HRC55-61 after the ultrasonic frequency thermal treatment is carried out, the surface layer metallographic structure reaches 3-7 level of the sorbite, the abrasive resistance and the toughness of the knuckle spindle are improved, the knuckle spindle can bear large impact force and contributes to the strengthening of the use safety, the production period is shortened and the production cost is saved.

Description

technical field [0001] The invention relates to a heat treatment method in the production process of steering knuckle pins. Background technique [0002] The steering knuckle pin is one of the main parts of the front axle of the car. It mainly bears wear and impact during the driving process of the car. Therefore, the steering knuckle pin requires strong anti-wear and fatigue resistance on the surface, and strong anti-fatigue performance on the core. impact toughness. At present, most steering knuckle pins on the market are made of 20CrMnTi carburized material through simple quenching heat treatment method. Martensite, the surface layer of the finished product has high hardness, and the core is low-carbon martensite. If this steering knuckle pin encounters sudden braking under overload and overspeed conditions, it is easy to break due to a strong impact force, so there is a relatively large big security risk. Contents of the invention [0003] The technical problem to b...

AI Technical Summary

Problems solved by technology

At present, most steering knuckle pins on the market are made of 20CrMnTi carburized material through simple quenching heat treatment method. Martensite, the surface layer of the finished product has high hardness, and the core is low-carbon martensite. If this steering knuckle pin encounters sudden braking under overload and overspeed conditions, it is easy to break due to a strong impact force, so there is a relatively large big security risk