Study of High Co Superhard High Speed Steel Surface

2009 ◽  
Vol 610-613 ◽  
pp. 253-256
Author(s):  
Zhong Hou Li ◽  
Sha Sha Liu ◽  
Zhi Yong Cheng

Cobalt- superhard high speed steel layer has been formed on the surface of low alloy steel 20Cr2V by tungsten-molybdenum-cobalt plasma surface alloying and following plasma carbonizing. After plasma surface alloying, a homogeneous and dense surface alloying layer was formed, thickness of which is 200μm. Composition, microstructure and properties of the alloying layer were investigated. Contents of W, Mo, Co, Cr, V and C in the surface layer reach 8%,5%, 6% ,4%,1.5% and 1.5% or so respectively. The concentrations of alloy elements basically meet the requirements of high cobalt type superhard high speed steel. Constituent phases of the surface layer were martensite, M7C3 ,M2C and Cr3C2 carbides and μ phase after quenching treatment. The advanced gradient superhard high speed steel possesses not only high surface hardness, high anti-temper softening ability but also enough toughness.

2005 ◽  
Vol 475-479 ◽  
pp. 3955-3958
Author(s):  
Jin Yong Xu ◽  
Yan Ping Liu ◽  
Yuan Gao ◽  
Zhong Xu

The plasma surface alloying low-alloy high speed steel (HSS) is carried out in vacuum chamber where a source electrode (W-Mo) and a work piece are properly placed. By using the sputter of glow-discharge, under the common function of electric field and temperature field, ?????? the desired alloying elements (W- Mo) are sputtered from the source cathode, traveling toward the substrate. Subsequently the alloying elements deposit onto the surface of the substrate, forming alloy diffusion layer which the depth may vary from several micron to several hundreds micron. In the end a surface low-alloy HSS steel would be produced after ultra-saturation ion carbonization. The composition of the alloyed layer is equal or similar with it of low-alloy HSS. The carbonized layer, without coarse eutectic ledeburite structure, possesses high density of finely and dispersed alloy carbides with tungsten equivalent 10% above and a significant improvement in surface hardness and wear resistance. The principle of plasma surface alloying and its test results and commercial products application are introduced in this paper.


2005 ◽  
Vol 475-479 ◽  
pp. 3939-3942
Author(s):  
Yuan Gao ◽  
Jin Yong Xu ◽  
Yan Ping Liu ◽  
Zhi Yong He ◽  
Zhong Xu

Plasma surface alloying for low alloy high speed power hack saw blades was introduced.The bulk material of the blade is made of low alloy steel, while the teeth of which possess a composition of high speed steel like as a result of surface modification by a plasma surface alloying process.It is a solid diffusion process eliminating method avoids the formation of coarse primary carbides which is a major problem encountered in the production of smelting high speed steel. As a result the carbides in the layer of high speed steel are fine and well-distributed.Therefore,it has not only well wear-resistance but also toughness. Besides, the blade also has the advantages of ease manufacturing and low cost.


2007 ◽  
Vol 353-358 ◽  
pp. 1741-1744 ◽  
Author(s):  
Zhong Hou Li ◽  
Nai Juan Ren ◽  
Yan Mei Zhang

The surface age alloy of Fe-Co-W-Mo was formed on 25Cr2Mo2V steel by double glow plasma surface alloying technique. The effects of processing parameters on the depth, composition and constituent phases of surface alloying layer were investigated. Results indicate that the plasma processing parameters influenced significantly the surface alloying process. The composition of the surface layer nears W11Mo7Co23Fe59wt%, the depth of the surface alloying layer is 150μm after processing at 1100°C for 6hr. The microstructure of the cross section was composed of three sub-layers, that is, the deposition layer, the diffusion layer and the matrix. The constituent phases of the deposition layer were Fe7W6 type μ phase Fe2W type laves phase, Fe3Mo and a little amount of M2C type carbide, that of the diffusion layer were α-Fe and some intermetallics.


2014 ◽  
Vol 709 ◽  
pp. 403-409 ◽  
Author(s):  
Bauyrzhan K. Rakhadilov ◽  
Mazhyn Skakov ◽  
Erlan Batyrbekov ◽  
Michael Scheffler

The article investigates the changing in the structure and phase composition of the R6M5 high-speed steel surface layer after electrolytic-plasma nitriding. It is found that after electrolytic-plasma nitriding on the R6M5 steel surface, modified layer is formed, which consist from a diffusion layer. It was showed phase composition of difysion layer is changing depending on the nitriding. It is found that electrolytic-plasma nitriding lead to accelerated formation of the modified layer. It is determined that after electrolytic-plasma nitriding on the high-speed steel surface, modified layer is formed, consisting only of the diffusion layer.


2013 ◽  
Vol 594-595 ◽  
pp. 1117-1121
Author(s):  
Мazhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Merey Rakhadilov

In this work the influence of electrolytic-plasma nitriding on the abrasive wear-resistance of R6M5 high-speed steel were under research. We registered that after electrolytic-plasma nitriding on R6M5 steel surface modified layer is formed with 20-40 μm thickness and with increased microhardness of 9000-12200 MPa. Testing mode for the nitrided samples high-speed steel on abrasive wear developed. It is established, that electrolyte-plasma nitriding allows to increase wear-resistance of R6M5 steel surface layer comparing to original. It was determined that abrasive wear-resistance of R6M5 steel surface layer is increased to 25% as a result of electrolytic plasma nitriding. Thus, studies have demonstrated the feasibility and applicability of electrolytic-plasma nitriding in order to improve cutting tools work resource, working under friction and wear conditions.


2008 ◽  
Vol 373-374 ◽  
pp. 426-429
Author(s):  
Yue Fei Zhang ◽  
Xin Chao Bian ◽  
Qiang Chen ◽  
Guang Qiu Zhang ◽  
Yuan Gao

A multiple-needle-cathode plasma surface alloying process has been developed for improving the properties of surface hardness, wear resistance and corrosion resistance of Ti6Al4V. The process is carried out at temperatures below 800 °C and facilitates the simultaneous introduction of W, Mo,nitrogen and carbon into the surfaces of Ti6Al4V forming gradient alloying layer structure with an extremely high hardness. The process is performed at working pressure of 30Pa-80Pa with 9-needle-cathode of W80Mo20 alloy rods array and a high pure graphite plate cathode as target electrode. A maximum microhardness is 4-6 times much harder than the substrate. The results show the presence of carbide and nitride ceramics phases contribute to high microhardness and wear resistance. The multiple-needle-cathode discharge plasma treatment is an effective method for improvement of the mechanical and tribological properties of titanium-base alloys by formation of graded diffusion hard surface layers. The present paper describes this novel process and properties characteristics.


2014 ◽  
Vol 1040 ◽  
pp. 753-758 ◽  
Author(s):  
Mazhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Erlan Batyrbekov ◽  
Michael Scheffler

In the article changes in the structure and mechanical properties of R6M5 steel surface layer after electrolytic-plasma nitriding are shown. The optimal mode of electrolytic-plasma nitriding of R6M5 high-speed steel in electrolyte based on carbamide, which allows saturation of the surface with nitrogen from low-temperature plasma and get the modified layer of high hardness and wear-resistance. It is established, that after electrolytic-plasma nitriding reduced R6M5 steel wear rate and increases its resistance to abrasive wear. Perspectivity of use an electrolytic-plasma nitriding method to improve performance cutting tools made from R6M5 steel is shown.


2006 ◽  
Vol 118 ◽  
pp. 85-90 ◽  
Author(s):  
Y. Sun ◽  
E. Haruman

This paper gives a brief review on the three low temperature plasma surface alloying processes that have been developed in recent years to engineer the surfaces of austenitic stainless steels to achieve much enhanced surface hardness and wear resistance, without compromising their corrosion resistance. These include low temperature plasma nitriding, low temperature plasma carburizing and the newly developed hybrid process involving the simultaneous incorporation of nitrogen and carbon to form a dual layer structure. The processing, structural and property characteristics of each process are discussed briefly in this paper.


2012 ◽  
Vol 509 ◽  
pp. 204-207
Author(s):  
Feng Zhang ◽  
Ze Ying Wang ◽  
Zhen Xia Wang ◽  
Zhi Yong He

Plasma surface alloying technology was applied to introduce Ni element into Ti6Al4V to improve its tribological property. The microstructure, composition, phase constituent and hardness of the alloyed layer were examined. Wear mechanisms were discussed on the basis of wear scar observations. The tribological performance of the alloyed layer was investigated by ball-on-disk sliding tests in different environments. The results showed that the Ti-Ni alloyed layer was about 12μm in thickness and the content of Ni element reached to 28% on the surface. The surface hardness of the layer was 677HV, nearly twice as the untreated Ti6Al4V. The wear resistance of the modified Ti6Al4V substrate was improved obviously in different environments.


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