Process for tufftriding amino gas

A soft nitriding and gas technology, which is applied in the field of soft nitriding process, can solve the problems of uneven hardness and permeation layer, small workpiece deformation, and low processing temperature, so as to avoid surface decarburization, ensure uniformity, and reduce deformation Effect

Inactive Publication Date: 2015-04-08
HENGYANG FENGSHUN AXLE CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Soft nitrocarburizing is a surface treatment process that mainly includes N infiltration and C infiltration. Soft nitriding has the advantages of low treatment temperature, short time, The deformation of the workpiece is small, not limited by the steel type, and can significantly improve the fatigue strength, wear resistance and corrosion of the workpiece. It is widely used in the treatment of wear-resistant workpieces such as molds, measuring tools, and knives. The process often has defects such as low workpiece hardness, uneven hardness and infiltrated layer, and shallow infiltrated layer. Therefore, it is necessary to seek an optimized soft nitriding process to avoid the above defects as much as possible.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] A kind of ammonia gas nitrocarburizing process, comprises the following steps:

[0019] (1) Put the steel workpiece into the heating furnace and heat it to 800°C for normalizing, and keep it warm for two hours, and then quench and temper the steel workpiece. The normalizing process and quenching and tempering process ensure a certain CO2 atmosphere in progress;

[0020] (2) Soak the quenched and tempered steel workpiece in a mixed solution of concentrated sulfuric acid and potassium dichromate for surface pretreatment, and the soaking time is 1 hour;

[0021] (3) After the surface pretreated steel workpiece is cleaned with alcohol for simple surface cleaning, it is placed in a nitriding furnace for soft nitriding treatment. The nitriding medium is NH3, N2, CO2, and the volume content of NH3 The volume content of N2 is 51%, the volume content of N2 is 44%, the volume content of CO2 is 5%, the temperature of nitriding treatment is 555°C, the time of nitriding treatment i...

Embodiment 2

[0027] A kind of ammonia gas nitrocarburizing process, comprises the following steps:

[0028] (1) Put the steel workpiece into the heating furnace and heat it to 800°C for normalizing, and keep it warm for two hours, and then quench and temper the steel workpiece. The normalizing process and quenching and tempering process ensure a certain CO2 atmosphere in progress;

[0029] (2) Soak the quenched and tempered steel workpiece in a mixed solution of concentrated sulfuric acid and potassium dichromate for surface pretreatment, and the soaking time is 2 hours;

[0030] (3) After the surface pretreated steel workpiece is cleaned with alcohol for simple surface cleaning, it is placed in a nitriding furnace for soft nitriding treatment. The nitriding medium is NH3, N2, CO2, and the volume content of NH3 The volume content of N2 is 52%, the volume content of N2 is 43%, the volume content of CO2 is 5%, the temperature of nitriding treatment is 600°C, the time of nitriding treatment ...

Embodiment 3

[0036] A kind of ammonia gas soft nitriding process, comprises the following steps:

[0037] (1) Put the steel workpiece into the heating furnace and heat it to 800°C for normalizing, and keep it warm for two hours, and then quench and temper the steel workpiece. The normalizing process and quenching and tempering process ensure a certain CO2 atmosphere in progress;

[0038] (2) Soak the quenched and tempered steel workpiece in a mixed solution of concentrated sulfuric acid and potassium dichromate for surface pretreatment, and the soaking time is 1.5 hours;

[0039] (3) After the surface pretreated steel workpiece is cleaned with alcohol for simple surface cleaning, it is placed in a nitriding furnace for soft nitriding treatment. The nitriding medium is NH3, N2, CO2, and the volume content of NH3 50%, the volume content of N2 is 45%, the volume content of CO2 is 5%, the temperature of nitriding treatment is 650°C, the time of nitriding treatment is 2.5 hours, and the decomp...

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PUM

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Abstract

The invention provides a process for tufftriding amino gas. The process comprises a heating treatment process before steel workpiece tufftriding treatment, a surface pre-treatment process, a tufftriding treatment process and a tufftriding subsequent treatment process, wherein in the heating treatment process, normalizing treatment and tempering and hardening treatment are adopted; in the tufftriding treatment process, ammonia, nitrogen and carbon dioxide are adopted as nitriding mediums, each tufftriding process parameter is reasonably controlled, a relatively low heating and cooling speed is adopted for a nitriding furnace, a certain amount of nitrogen is continuously introduced after the tufftriding process is completed to maintain the positive pressure atmosphere of the nitriding furnace, and the nitriding furnace is instantly cooled with water when the temperature of the nitriding furnace is reduced to 200 DEG C until the surface temperature of the steel workpiece reaches room temperature. By adopting the scheme, the process for tufftriding amino gas has the advantages of improving the hardness of steel workpieces and leading uniformity of hardness and an infiltrated layer to rise and the infiltrated layer to be deep.

Description

technical field [0001] The invention relates to a soft nitriding process, in particular to an amino gas soft nitriding process. Background technique [0002] Soft nitriding is a surface treatment process that is mainly based on nitrogen infiltration and also has C infiltration. Soft nitriding has the advantages of low treatment temperature, short time, small deformation of the workpiece, and is not limited by steel types, so it can significantly improve the hardness of the workpiece. The advantages of fatigue strength, wear resistance and corrosion are widely used in the treatment of wear-resistant workpieces such as molds, measuring tools, and cutting tools. However, the existing soft nitriding process often has low hardness of the workpiece, uneven hardness and infiltration layer, Therefore, it is necessary to find an optimized soft nitriding process to avoid the above defects as much as possible. Contents of the invention [0003] The purpose of the present invention ...

Claims

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Application Information

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IPC IPC(8): C23F17/00C23C8/32
Inventor 刘登发尤华胜
Owner HENGYANG FENGSHUN AXLE CO LTD
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