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Method for producing gradient nanometer structure on martensitic steel surface

A martensitic steel and nanostructure technology, which is applied in the field of producing gradient nanostructures on the surface of martensitic steel, can solve the problems of peeling, complicated treatment process, scratched surface, etc., and achieves the effect of low cost and simple process

Active Publication Date: 2016-03-02
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

[0006] However, the above methods have some problems in terms of process implementation and treatment quality, which limit their industrial application to a certain extent:
[0007] (1) Since the surface layer material prepared by plasma spraying or surface deposition technology and the base material have different thermal physical properties such as elastic modulus and linear expansion coefficient, the bonding performance between them may affect the performance of the material. Under the harsh service environment, cracks are easy to occur between the surface layer material and the substrate until the peeling of the surface layer occurs
[0008] (2) Although the alloyed surface layer obtained by surface alloying technology has a high bonding strength with the substrate, the treatment process itself is relatively complicated. The surface alloying process usually requires high temperature, long time, and high energy consumption. Coarsening may occur, and the process itself will pollute the environment to a certain extent
[0009] (3) Although methods such as shot peening, supersonic metal particle bombardment, and laser shock strengthening can obtain a certain thickness of residual compressive stress layer on the surface of the material, the grain refinement degree of the surface layer is limited, and the thickness of the surface nano-layer is small or even non-existent. The surface nanostructure is formed, so there is limited room for improvement of the surface properties of the material, and the method of shot peening and supersonic metal particle bombardment has problems such as noise and dust disposal
Therefore, the surface mechanical strengthening treatment method of martensitic steel materials also has certain limitations. If the treatment method and process are not selected properly, the strengthening effect will be poor, the quality of the treatment cannot be guaranteed, and martensitic steel may appear during the treatment process. Defects such as cracks, scratches and surface peeling on the surface of the material seriously affect the surface quality
For example, after the surface of 40CrNiMo7 martensitic steel is treated by two methods of shot peening and Hawker, the thickness of the surface deformation layer (or hardened layer) obtained is small (50 μm and 75 μm respectively), and the surface hardness value ( Respectively 3.0GPa and 3.1GPa) relative to the hardness value of the substrate (2.7GPa), the increase is small, and the surface finish is poor

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  • Method for producing gradient nanometer structure on martensitic steel surface
  • Method for producing gradient nanometer structure on martensitic steel surface
  • Method for producing gradient nanometer structure on martensitic steel surface

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] M3200 martensitic stainless steel cylindrical test bar with a diameter of 80mm, its chemical composition is (wt.%): C0.07%, Si1%, Mn0.75%, S0.025%, P0.03%, Cr16%, Ni5.5%, Mo0.95%, Co0.2%, Fe balance; the initial supply state is quenched + tempered state. The SMGT surface nanometerization method of the present invention is used for processing, and the diameter of the WC-Co cemented carbide ball of the SMGT processing tool is 8mm, and an oily coolant is used for lubrication and cooling during the processing. The main technical parameters are as follows:

[0048] The linear velocity v of the outer circle of the martensitic stainless steel test rod 1 =1.1×10 4 mm / min;

[0049] Feed speed v of SMGT machining tool 2 =6×10 -2 mm / r;

[0050] Processing pass n=6 times;

[0051] The indentation depth of cemented carbide balls on the surface of martensitic stainless steel for each processing pass is: a p(1) = 20 μm, a p(2) = 40 μm, a p(3) = 60 μm, a p(4) = 80 μm, a p(5...

Embodiment 2

[0054] 1Cr13 martensitic stainless steel shaft with a diameter of 100mm, its chemical composition is (wt.%): C0.10~0.15%, Si1%, Mn1%, S0.025%, P0.03%, Cr11.5~13.5% , Ni0.6%, Cu0.3%, Fe balance; the initial supply state is quenched + tempered state. The SMGT surface nanometerization method of the present invention is used for processing, and the diameter of the WC-Co cemented carbide ball (or GCr15 ball) of the SMGT processing tool is 8mm, and an oily coolant is used for lubrication and cooling during the processing. The main technical parameters are as follows:

[0055] The linear velocity v of the outer circle of the martensitic stainless steel shaft 1 =1.4×10 4 mm / min;

[0056] Feed speed v of SMGT machining tool 2 =3×10 -2 mm / r;

[0057] Processing pass n=1 time;

[0058] Indentation depth a of cemented carbide balls on the surface of martensitic stainless steel p = 50 μm.

[0059] The test results show that after SMGT surface nano-processing, the surface of 1Cr13 ...

Embodiment 3

[0061] 40CrNiMo7 martensitic steel shaft with a diameter of 120mm, its chemical composition is (wt.%): C0.37%, Si0.17%, Mn0.8%, S0.025%, P0.025%, Cr0.9% , Ni1.9%, Cu0.025%, Mo0.25%, Fe balance; initial supply state is quenched + tempered state. The SMGT surface nanometerization method of the present invention is used for processing, and the diameter of the WC-Co cemented carbide ball (or GCr15 ball) of the SMGT processing tool is 8mm, and an oily coolant is used for lubrication and cooling during the processing. The main technical parameters are as follows:

[0062] The linear velocity v of the outer circle of the martensitic steel shaft 1 =1.1×10 4 mm / min;

[0063] Feed speed v of SMGT machining tool 2 =3×10 -2 mm / r;

[0064] Processing pass n=2 times;

[0065] The indentation depth of cemented carbide balls on the surface of martensitic steel for each processing pass is: a p(1) = 25 μm, a p(2) = 50 μm.

[0066] The test results show that the surface roughness Ra va...

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Abstract

The present invention discloses a method for producing a gradient nanometer structure on the martensitic steel surface, and belongs to the technical field of metal material surface nanocrystallization. According to the method, a martensitic steel rotation member is treated by using a surface mechanical rolling processing technology (SMGT), the SMGT processing cutter hard ball capable of freely rolling performs high speed rolling and pressing on the martensitic steel rotation member surface, the martensitic steel surface to be treated is subjected to high speed plasticity deformation, and under the conditions of high strain, high strain rate and high strain gradient, the coarse grain structure on the surface layer is converted into the gradient structure sequentially comprising nano-grains, submicron grains and micro-scale grains. According to the present invention, the surface roughness Ra value of the martensitic steel being subjected to the SMGT surface nanocrystallization treatment is less than 0.30 [mu]m, and the surface property is significantly improved.

Description

technical field [0001] The invention relates to the technical field of metal material surface nanometerization, in particular to a method for generating gradient nanostructures on the surface of martensitic steel. Background technique [0002] The damage of engineering metal materials and devices mostly originates from the surface, so the structure and performance of the surface of the material determine the service behavior and life of the overall material and device to a large extent. The main methods and approaches to improve the surface properties of metal materials include: [0003] (1) Using methods such as plasma spraying, physical vapor deposition or chemical vapor deposition to prepare one or more layers of materials with special performance on the surface of the material; [0004] (2) Using surface alloying technologies such as carburizing, nitriding, aluminizing or chromizing to change the composition and phase structure of the material surface, etc., to prepare ...

Claims

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Application Information

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IPC IPC(8): C21D7/04
Inventor 张伟华黄海威王镇波卢柯
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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