Plasma Surface Alloying W-Mo Low-Alloy HSS

2005 ◽  
Vol 475-479 ◽  
pp. 3955-3958
Author(s):  
Jin Yong Xu ◽  
Yan Ping Liu ◽  
Yuan Gao ◽  
Zhong Xu
Keyword(s):  
High Speed ◽  
Surface Hardness ◽  
High Speed Steel ◽  
Alloying Elements ◽  
Work Piece ◽  
Test Results ◽  
Surface Alloying ◽  
Plasma Surface ◽  
The Common ◽  
Plasma Surface Alloying

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.

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
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Steel Surface ◽  
High Surface ◽  
Surface Hardness ◽  
High Speed Steel ◽  
Low Alloy Steel ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Plasma Surface Alloying

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.

A New Low Alloy High Speed Power Hack Saw Blades

2005 ◽  
Vol 475-479 ◽  
pp. 3939-3942
Author(s):  
Yuan Gao ◽  
Jin Yong Xu ◽  
Yan Ping Liu ◽  
Zhi Yong He ◽  
Zhong Xu
Keyword(s):  
High Speed ◽  
Bulk Material ◽  
Low Cost ◽  
High Speed Steel ◽  
Low Alloy Steel ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Solid Diffusion ◽  
Primary Carbides ◽  
Plasma Surface Alloying

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.

Plasma Surface Alloying Process of a Fe-W-Mo-Co Surface Age Hardening High Speed Steel

2007 ◽  
Vol 353-358 ◽  
pp. 1741-1744 ◽  
Author(s):  
Zhong Hou Li ◽  
Nai Juan Ren ◽  
Yan Mei Zhang
Keyword(s):  
Diffusion Layer ◽  
High Speed ◽  
High Speed Steel ◽  
Processing Parameters ◽  
Age Hardening ◽  
Surface Alloying ◽  
Plasma Surface ◽  
The Matrix ◽  
Glow Plasma ◽  
Plasma Surface Alloying

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.

Multiple Needle Cathodes Plasma Surface Alloying of Ti6Al4V with W-Mo-C-N

2008 ◽  
Vol 373-374 ◽  
pp. 426-429
Author(s):  
Yue Fei Zhang ◽  
Xin Chao Bian ◽  
Qiang Chen ◽  
Guang Qiu Zhang ◽  
Yuan Gao
Keyword(s):  
Wear Resistance ◽  
Layer Structure ◽  
Surface Hardness ◽  
High Hardness ◽  
Surface Alloying ◽  
Cathode Plasma ◽  
Working Pressure ◽  
Plasma Surface ◽  
Pure Graphite ◽  
Plasma Surface Alloying

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.

Low Temperature Plasma Surface Alloying of Austenitic Stainless Steels

2006 ◽  
Vol 118 ◽  
pp. 85-90 ◽  
Author(s):  
Y. Sun ◽  
E. Haruman
Keyword(s):  
Low Temperature ◽  
Stainless Steels ◽  
Layer Structure ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Low Temperature Plasma ◽  
Surface Alloying ◽  
Temperature Plasma ◽  
Plasma Surface ◽  
Plasma Surface Alloying

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.

Tribological Performance of Ti6Al4V Alloy Treated by Plasma Surface Ni Alloying

2012 ◽  
Vol 509 ◽  
pp. 204-207
Author(s):  
Feng Zhang ◽  
Ze Ying Wang ◽  
Zhen Xia Wang ◽  
Zhi Yong He
Keyword(s):  
Wear Resistance ◽  
Wear Mechanisms ◽  
Tribological Property ◽  
Surface Hardness ◽  
Tribological Performance ◽  
Alloyed Layer ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Phase Constituent ◽  
Plasma Surface Alloying

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.

Analysis of Unit and Binary Diffusion in Glow Plasma Surface Alloying Process

2011 ◽  
Vol 704-705 ◽  
pp. 1141-1145
Author(s):  
Xuan Nan Chen ◽  
Yuan Gao ◽  
Bing Li ◽  
Xue Feng Huang
Keyword(s):  
Solid Solution ◽  
Diffusion Coefficients ◽  
Alloying Elements ◽  
Production Cycle ◽  
Surface Alloying ◽  
Surface Phase ◽  
Binary Diffusion ◽  
Phase Component ◽  
Plasma Surface ◽  
Plasma Surface Alloying

Q195 steel was conducted by plasma chromizing and Cr-Ni surface alloying process to research the relationship between unit diffusion and binary diffusion. After studying the thickness, composition, phase component of the layer and diffusion coefficients of alloying elements, results showed that (1) the thickness of chromizing layer was 150μm; the surface phase component was Fe-Cr solid solution; the surface chromium contents was 21.4%. The thickness of Cr-Ni co-diffusion layer was 40μm; the surface phase component was Fe-Cr-Ni solid solution; the surface contents were: Cr 16.14%, Ni 48.16%. The alloying elements distributed in downward gradient from the outside to the inside. (2) Compared with plain surface alloying technique, using plasma surface alloying technique can get higher diffusing speed and shorten production cycle time. (3) The diffusion coefficients decreased as the diffusion distance increased. (4)Compared with chromizing, Cr-Ni co-diffusion increased the utilization ratio of alloying elements but decreased the diffusion speed of alloying elements, thus the surface alloying content increased and the thickness of alloying layer decreased.

Research on the Carbides of Its Alloying Layer Conducted by W-Mo-Y Surface Alloying and Carburizing Process

2012 ◽  
Vol 472-475 ◽  
pp. 2891-2895
Author(s):  
Hang Wei Cai ◽  
Hong Guan Wu ◽  
Zhi Kang Ma ◽  
Cheng Lei Wang ◽  
Lin Yuan ◽  
...  
Keyword(s):  
High Speed ◽  
Discharge Plasma ◽  
Carbide Particle ◽  
High Speed Steel ◽  
Glow Discharge Plasma ◽  
Surface Alloying ◽  
Eutectic Carbide ◽  
Quenching Process ◽  
Plasma Surface Alloying ◽  
Carburizing Process

Q235 steel was processed by solid carburizing and quenching after conducted by W-Mo-Y double glow-discharge plasma surface alloying process. Finally carbon contents, the morphologies and phases of the samples' surface were analyzed. The results show as follows: Carbon contents of the samples' surface are 1.28 wt%, 1.36 wt%, 1.51 wt% respectively after W-Mo-Y alloying layer (also called co-penetrated layer) was processed by solid carburizing at 960 °C, 980 °C, 1020 °C respectively; The amount of the carbides in W-Mo-Y alloying layer is obviously more than that of the carbides in W-Mo alloying layer; The granular carbides distribute dispersively and uniformly in alloying layer, and the sizes of carbide particle are less than 1 μm; There is no eutectic carbide at the grain boundaries; With temperatures of carburizing and quenching process rising, the carbides increases in number; After W-Mo-Y alloying layer was carburized and quenched at 1020 °C, the phases of alloying layer are Fe2C, W2C, Fe2MoC, MoC, Fe3C, Mo2C and Y2C3; and the types of their carbides are M3C, M2C, and MC, which are different from the types of W-Mo carbides in general metallurgy high-speed steel (HSS). It can be seen from the available, the morphologies, the sizes and the amount of surface HSS's carbides can be adjusted by heat treatment.

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