Rapid Quenching and Tempering Treatment Method of Low Carbon and Low Alloy Steel Cast Steering Knuckle

Abstract

The invention relates to a rapid quenching and tempering method of a steering knuckle casted by using low-carbon low-alloy steel. The method comprises the following steps: setting a quenching heating temperature at AC3 + 90-110DEG C, tapping off a casting after the surface temperature of the casting in a measuring furnace of a temperature measurer reaches the quenching heating temperature, quenching, rising a tempering heating temperature to a value 20-30DEG C higher than a present tempering heating temperature, shortening a tempering insulation time to be a value being 1 / 2-1 / 3 of a present tempering insulation time when the surface temperature of the casting reaches the tempering heating temperature, carrying out tempering heat insulation, and cooling. The method has the advantages of high quenching and tempering heating temperatures, short heat insulation time, shortened production period, improved production efficiency and reduced energy consumption.

Description

technical field [0001] The invention belongs to the field of metal heat treatment, in particular to a rapid quenching and tempering treatment method for low-carbon and low-alloy steel cast steering knuckles. Background technique [0002] Steering knuckle is an important component with complex stress on the car. It is generally made of 40Cr or 40MnB steel die forging. For the steering knuckle with complex structure, it can save costs and shorten the production cycle by casting low-carbon and low-alloy steel. Low-carbon and low-alloy casting knuckles have strict requirements on mechanical properties and metallographic structure. On the premise of ensuring the mechanical properties and metallographic structure of the steering knuckle, the quenching and tempering treatment process is very critical to shorten the production cycle. [0003] For low-carbon and low-alloy steel castings, in order to eliminate casting defects such as dendrite segregation, coarse grains, uneven structu...

AI Technical Summary

Problems solved by technology

The traditional process requires annealing pretreatment, quenching and heat preservation takes 3 hours, tempering and heat preservation takes 5 hours, and the quenching and tempering heat preservation time is relatively long, resulting in thick oxide skin of castings, high energy consumption and low production efficiency

Due to the complex structure of low-carbon and low-alloy steel casting steering knuckles and the large difference in wall thickness, the mechanical properties and metallographic structure after heat treatment according to the traditional process often fail to meet the requirements, which is very unfavorable for mass production.

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