Preparing method of metal material surface nitriding deposition composite antifriction wear-resisting modification layer

A technology of metal materials and modified layers, applied in the direction of metal material coating process, coating, solid diffusion coating, etc. problems, to achieve uniform hardness, improved friction and wear resistance, and avoid edge effect problems.

Active Publication Date: 2017-06-23
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the difference in electric field distribution due to the geometric shape of the workpiece, the degree of ion bombardment is different, which in turn causes the inhomogeneity of the surface temperature of the workpiece, and finally there is a difference in heat and mass transfer on the surface of the workpiece.
AISI316L stainless steel has the problem of "edge effect" caused by the DCPN nitriding process. The hardness of the ring area is significantly higher than that of the center area, but the corrosion resistance is poor. The microstructure shows that the ring area is Cr2N phase, while the center area is S Mutually

Method used

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  • Preparing method of metal material surface nitriding deposition composite antifriction wear-resisting modification layer
  • Preparing method of metal material surface nitriding deposition composite antifriction wear-resisting modification layer
  • Preparing method of metal material surface nitriding deposition composite antifriction wear-resisting modification layer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] AISI304 austenitic stainless steel, its composition is (wt.%): 0.05C; 0.80Si; 1.50Mn; 17.5Cr; 9.50Ni; 0.013Mo; The surface of the sample was smoothed from coarse to fine with SiC sandpaper, and then polished. After cleaning with alcohol, place it on the anode potential platform in the nitriding furnace.

[0026] The furnace is evacuated to 15Pa, filled with ammonia gas and maintained at a working pressure of about 500Pa, the nitriding temperature is 440°C, the heat preservation nitriding treatment is carried out for 8 hours, and the furnace is cooled to below 200°C in an ammonia atmosphere to obtain a composite reduced nitriding deposition. wear-resistant modified layer, the cross-sectional morphology was observed by scanning electron microscope as figure 1 As shown in (a), a nitride layer with uniform thickness (about 6 μm) was prepared on the surface of AISI304 austenitic stainless steel, which has good corrosion resistance.

Embodiment 2

[0028] AISI304 austenitic stainless steel, its composition is (wt.%): 0.05C; 0.80Si; 1.50Mn; 17.5Cr; 9.50Ni; 0.013Mo; The surface of the sample was smoothed from coarse to fine with SiC sandpaper, and then polished. After cleaning with alcohol, place it on the anode potential platform in the nitriding furnace.

[0029] The furnace is evacuated to 15Pa, filled with ammonia gas and maintained at a working pressure of about 500Pa, the nitriding temperature is 480°C, the heat preservation nitriding treatment is carried out for 8 hours, and the furnace is cooled to below 200°C in an ammonia atmosphere to obtain a composite reduced nitriding deposition. wear-resistant modified layer, the cross-sectional morphology was observed by scanning electron microscope as figure 1 As shown in (b), the nitride layer on the surface of AISI304 austenitic stainless steel is thickened but accompanied by the precipitation of black phase.

Embodiment 3

[0031] AISI304 austenitic stainless steel, its composition is (wt.%): 0.05C; 0.80Si; 1.50Mn; 17.5Cr; 9.50Ni; 0.013Mo; The surface of the sample was smoothed from coarse to fine with SiC sandpaper, and then polished. After cleaning with alcohol, place it on the anode potential platform in the nitriding furnace.

[0032] The furnace is evacuated to 15Pa, filled with ammonia gas and maintained at a working pressure of about 500Pa, the nitriding temperature is 520°C, the heat preservation nitriding treatment is carried out for 8 hours, and the furnace is cooled to below 200°C in an ammonia atmosphere to obtain the nitriding deposition composite reduction. wear-resistant modified layer, the cross-sectional morphology was observed by scanning electron microscope as figure 1 As shown in (c), the thickness of the nitride layer on the surface of AISI304 austenitic stainless steel reaches 16 μm, and at the same time, the proportion of black dot phase precipitation continues to expand. ...

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Abstract

The invention discloses a preparing method of a metal material surface nitriding deposition composite antifriction wear-resisting modification layer, and belongs to the technical field of metal material surface treatment. A metal material workpiece surface is rubbed down, polished and cleaned, and is then placed on an anode potential platform in a hollow cathode discharge ion source nitriding furnace, the interior of the furnace is vacuumized to 10 Pa to 15 Pa, ammonia gas is inflated into the furnace, the work pressure is maintained to 100 Pa to 500 Pa, heat preservation nitriding is carried out for 8 h at the temperature of 440 DEG C to 520 DEG C, and after cooling, the nitriding deposition composite antifriction wear-resisting modification layer is obtained. A sample is located at the anode potential, ion bombardment is not needed, nitrogen atoms can permeate into an austenite matrix to form a nitriding reinforcing layer, the problem about the edge effect can be effectively solved, the hardness of the whole surface is uniform, after a metal workpiece is subject to anode nitriding, a nitriding deposition layer is formed on the surface, and the antifriction wear-resisting property is obviously improved.

Description

technical field [0001] The invention belongs to the technical field of metal material surface treatment, and in particular relates to a preparation method of a metal material surface nitriding deposition compound anti-friction and wear-resisting modified layer. Background technique [0002] Due to the dense passivation film on the surface, austenitic stainless steel has excellent corrosion resistance in oxidizing media. However, due to its low surface hardness and poor wear resistance, it will fail due to severe wear in practical applications. Nitriding is widely used as an important engineering technology to improve the surface hardness and wear resistance of austenitic stainless steel. AISI 316 austenitic stainless steel is treated with low-temperature ion nitriding technology, the precipitation of nitrides is completely suppressed, and a single-phase nitrided layer is obtained. XRD shows that the diffraction peaks of the original austenite matrix shift to lower angles, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C8/38
CPCC23C8/38
Inventor 何永勇李杨王伟赵军胡宝国
Owner TSINGHUA UNIV
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