New QPQ nitrocarburizing corrosion resistance process for iron casting surface

A technology of cast iron parts and new technology, which is applied in the direction of metal material coating technology, coating, solid-state diffusion coating, etc., can solve the problems of large environmental pollution and unsafety, and achieve improved corrosion resistance, uniformity, and improved The effect of thickness

Inactive Publication Date: 2016-04-20
SICHUAN QUANFENG NEW MATERIALS & TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the CNO in this formula - If the content is too high, it will pollute the environment and be unsafe

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] A new QPQ nitriding co-infiltration anticorrosion process on the surface of cast iron parts, the process steps are as follows:

[0035] 1) cleaning

[0036] Under the action of water-based cleaning agent, at 100A / dm 2 Electrolytic cleaning with a current density of 0.05s;

[0037] 2) Preheat

[0038] At a temperature of 350°C, heat the workpiece in an air furnace for 60 minutes;

[0039] 3) Nitrocarburizing

[0040] Place the preheated workpiece in a 420°C salt bath for 180 minutes;

[0041] 4) cleaning

[0042] Cool in air to less than 150°C, wash residual salt with hot water, rinse with water, and polish;

[0043] 5) Secondary preheating

[0044] At a temperature of 350°C, heat the workpiece in an air furnace for 60 minutes;

[0045] 6) Secondary nitrocarburizing

[0046] Place the preheated workpiece in a 420°C salt bath for 90 minutes;

[0047] 7) Oxidation and polishing

[0048] Rinse and polish the oxidized workpiece with clean water;

[0049] Describe...

Embodiment 2

[0051] A new QPQ nitriding co-infiltration anticorrosion process on the surface of cast iron parts, the process steps are as follows:

[0052] 1) cleaning

[0053] Under the action of water-based cleaning agent, at 150A / dm 2 Electrolytic cleaning with a current density of 0.1s;

[0054] 2) Preheat

[0055] At a temperature of 390°C, heat the workpiece in an air furnace for 30 minutes;

[0056] 3) Nitrocarburizing

[0057] Place the preheated workpiece in a 460°C salt bath for 150 minutes;

[0058] 4) cleaning

[0059] Cool in air to less than 150°C, wash residual salt with hot water, rinse with water, and polish;

[0060] 5) Secondary preheating

[0061] At a temperature of 390°C, heat the workpiece in an air furnace for 60 minutes;

[0062] 6) Secondary nitrocarburizing

[0063] Place the preheated workpiece in a 460°C salt bath for 90 minutes;

[0064] 7) Oxidation and polishing

[0065] Rinse and polish the oxidized workpiece with clean water;

[0066] Described n...

Embodiment 3

[0068] A new QPQ nitriding co-infiltration anticorrosion process on the surface of cast iron parts, the process steps are as follows:

[0069] 1) cleaning

[0070] Under the action of water-based cleaning agent, at 120A / dm 2 Electrolytic cleaning with a current density of 0.06s;

[0071] 2) Preheat

[0072] At a temperature of 360°C, heat the workpiece in an air furnace for 40 minutes;

[0073] 3) Nitrocarburizing

[0074] Place the preheated workpiece in a 430°C salt bath for 155 minutes;

[0075] 4) cleaning

[0076] Cool in air to less than 150°C, wash residual salt with hot water, rinse with water, and polish;

[0077] 5) Secondary preheating

[0078] At a temperature of 360°C, heat the workpiece in an air furnace for 35 minutes;

[0079] 6) Secondary nitrocarburizing

[0080] Place the preheated workpiece in a salt bath at 430°C for 90 minutes;

[0081] 7) Oxidation and polishing

[0082] Rinse and polish the oxidized workpiece with clean water;

[0083] Descr...

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PUM

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Abstract

The invention provides a new QPQ nitrocarburizing corrosion resistance process for an iron casting surface. The process comprises the following steps: 1) under the effect of a water base cleaning agent, the electrolytic cleaning is performed by 0.05-0.1 s with a current density of 100-150 A / dm2; 2) a workpiece is heated by 30-60 min in an air furnace at a temperature of 350-390 DEG C; 3) nitrocarburizing: the preheated workpiece is put in salt bath of 420-460 DEG C for treating by 150-180 min; 4) the workpiece is cooled below 150 DEG C in air; residual salt is cleaned by hot water; clear water is used for rinsing; and the polishing is performed; 5) the workpiece is heated by 30-60 min in the air furnace at a temperature of 350-390 DEG C; 6) the preheated workpiece is put in the salt bath of 420-460 DEG C for treating by 90 min; 7) the oxidized workpiece is rinsed by the clear water is used for rinsing, and is polished; and salt nitride comprises the following components in percentage by mass: 30-50% of urea, 4-8% of Na2CO3, 6-10% of K2CO3, 5-10% of Li2CO3, 12-25% of KCNO, 8-15% of NaCNO, 5-8% of NaCl, 4-8% of Na2S, 6-10% of K2S, and 2-5% of LiOH.

Description

technical field [0001] The invention belongs to the technical field of metal element manufacturing and processing industry, and in particular relates to a new technology of QPQ nitriding co-infiltration and anticorrosion on the surface of cast iron parts. Background technique [0002] The essence of QPQ (Quench-Polish-Quench, quenching-polishing-quenching) technology is low-temperature salt bath nitriding + salt bath oxidation or low-temperature salt bath nitrocarburizing + salt bath oxidation, which is a surface modification technology for metal parts , has the advantages of high corrosion resistance, high wear resistance and micro deformation. The surface of the workpiece treated by QPQ technology is Fe3O4 oxide film, and its corrosion resistance is much higher than the level of surface protection technologies such as chromium plating and nickel plating. Medium carbon steel can replace stainless steel in many fields after QPQ treatment. At the same time, the QPQ process c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C8/58C23C8/54
CPCC23C8/58C23C8/54
Inventor 唐刚全张丰琼
Owner SICHUAN QUANFENG NEW MATERIALS & TECH CO LTD
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