A kind of 12crni3a carburizing and quenching method

Abstract

The invention discloses a 12CrNi3A carburizing and quenching method. The 12CrNi3A carburizing and quenching method comprises the steps that methyl alcohol is used as carrier gas and acetone is used asa permeating agent, carbon potentials in a carburizing furnace are monitored and controlled by adopting an oxygen probe, firstly, multi-stage heating and heat preservation are carried out above the critical temperature of 12CrNi3A material austenitic transformation and below 880 DEG C, and the carbon potentials of the stages are higher than the saturated carbon concentration of the material underthe temperature; then, warming is carried out to (880-910) DEG C, and the carburized speed is accelerated to obtain a carburized layer with a certain depth; and finally, cooling is carried out to thequenching temperature (810-830) DEG C and quenching is carried out after the heat preservation is carried out for certain time, and cold treatment and low-temperature tempering treatment are carriedout. According to the 12CrNi3A carburizing and quenching method, automatic production is easy to realize, toxicity of a carburizing agent is small, and harm to environment and human body is little; the carburized carbon potentials are low, carbon deposition is not prone to occurring in the furnace, and the production environment is greatly improved; the stability is good, and the quality of products is stable; and direct quenching is carried out after carburizing, energy sources are saved while the carburizing quality is guaranteed, and the production efficiency is high.

Description

technical field [0001] The invention belongs to special processing technology and relates to a new process method of carburizing and quenching of 12CrNi3A material. Background technique [0002] As we all know, during the operation of the engine, the transmission gear is subjected to complex stresses such as severe heavy load, wear, contact fatigue, and impact. The gear teeth need sufficient toughness, hardness, wear resistance, and fatigue resistance to meet special requirements. . Studies have shown that when a certain amount of granular carbides are distributed in the carburized layer, higher hardness, wear resistance and contact fatigue performance can be obtained. This characteristic can be applied to carburizing of engine gears. In fact, some foreign high-performance This is exactly the case with engine gear carburized layers. [0003] 12CrNi3A material is a kind of high-quality carburized steel, which is often used to make gears. However, due to the low chromium (Cr...

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Problems solved by technology

[0003] 12CrNi3A material is a kind of high-quality carburized steel, which is often used to make gears. However, due to the low chromium (Cr) content of 12CrNi3A material, it is difficult to obtain carbides after carburizing the gear parts processed by it. In order to solve this problem, such as figure 1 As shown, at present, the drop volume control penetrating agent method is often used, using benzene (or kerosene) as the penetrating agent and methanol as the carrier gas, and promoting the formation of carbides by increasing the drop volume of benzene (or kerosene). Because the control factor is too large, it is difficult to realize automatic production; benzene is highly toxic and harmful to the environment and human body; benzene (or kerosene) is used as a penetrating agent, easy to deposit carbon in the furnace, and the working environment is poor; the process stability is poor, and the product quality cannot be effectively obtained. control, low productivity

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