Austenitic stainless steel nitriding treatment system and method based on hollow cathode ion source

A technology of austenitic stainless steel and hollow cathode, which is applied in coating, metal material coating process, solid-state diffusion coating, etc., can solve the problem of low nitriding rate of too long, so as to improve nitriding efficiency and accelerate diffusion rate , Improving the effect of nitriding quality

Active Publication Date: 2018-01-23
TSINGHUA UNIV
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Problems solved by technology

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art in the low-temperature nitriding of austenitic stainless steel, which tak

Method used

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  • Austenitic stainless steel nitriding treatment system and method based on hollow cathode ion source
  • Austenitic stainless steel nitriding treatment system and method based on hollow cathode ion source
  • Austenitic stainless steel nitriding treatment system and method based on hollow cathode ion source

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Embodiment 450

[0030] 2) Put multiple parts into the vacuum nitriding furnace between the two metal plates where the hollow cathode device is installed, connect it to the cathode of the power supply, cover the furnace cover, turn on the air pump to vacuum the nitriding furnace, and pass cooling water; Evacuate to 5-15Pa (10Pa in this embodiment, you can see the value from the pressure indicator, pressure, temperature, voltage, current and gas flow, etc. can be displayed on the computer of the control system), adjust the working voltage (700-900V) and duty cycle (70%-80%), then open the ammonia cylinder, adjust the flow meter to maintain the air pressure at 400-450Pa (450Pa in this embodiment);

[0031] 3) Raise the temperature of the parts in the vacuum nitriding furnace, adjust the current and pressure (control the pressure by adjusting the flow meter on the ammonia cylinder, and ensure the stable discharge of the hollow cathode, the temperature rise rate is 15-25 degrees / min, the temperatur...

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Abstract

The invention relates to an austenitic stainless steel nitriding treatment system and method based on a hollow cathode ion source and belongs to the technical field of austenitic stainless steel nitriding treatment. The system comprises a power source system, a vacuum nitriding furnace, a hollow cathode device placed in the furnace, a gas extracting system, a gas supply system, a measuring and controlling system, a connection pipeline and a valve; the structure of the hollow cathode device in the vacuum nitriding furnace is composed of a plurality of metal plates arranged in the furnace in parallel; each metal plate is provided with a plurality of long strip grooves arranged at intervals; and through holes arranged at intervals are formed in each groove. According to the method, after a plurality of parts are cleaned, are placed between every two metal plates of the hollow cathode device installed in the vacuum nitriding furnace and are subjected to nitriding treatment, temperature rises to 500-550 DEG C, the heat preserving time is 0.5 h to 1.5 h, then cooling is performed, and the parts are taken out. By means of the austenitic stainless steel nitriding treatment system and method based on the hollow cathode ion source, the gas ionizing rate is increased, the plasma concentration is increased, the surface hardness and the abrasion resistance of austenitic stainless steel canbe improved, the corrosion resistant performance of the austenitic stainless steel is not affected, and the nitriding efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of nitriding treatment of austenitic stainless steel, and in particular relates to a nitriding treatment system and method of austenitic stainless steel based on a hollow cathode ion source. Background technique [0002] Due to the existence of a passivation film on the surface of austenitic stainless steel (such as Cr 2 o 3 ), so in conventional gas nitriding at relatively low temperatures, nitrogen is difficult to penetrate. During gas nitriding, the depassivation of the workpiece surface becomes an essential step. For example, after pre-heat treatment of pickling and shot blasting, the passivation film on the surface is removed, and its regeneration must be inhibited. In DC ion nitriding, due to the strong cathode sputtering effect, the oxide layer can be effectively removed from the stainless steel surface. Therefore, nitrogen can also be effectively transported below 400 °C. [0003] A large number ...

Claims

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Application Information

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IPC IPC(8): C23C8/38C23C8/26
Inventor 何永勇李杨朱宜杰王伟赵军胡宝国
Owner TSINGHUA UNIV
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