Research on Microstructures of Alloyed Layer by Plasma Surface Alloying with Tungsten and Molybdenum

2005 ◽  
Vol 297-300 ◽  
pp. 1108-1112
Author(s):  
Gao Yuan ◽  
Jin Yong Xu ◽  
Yan Ping Liu ◽  
Jian Zhong Wang ◽  
Xiaoyun Kui ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Composition ◽  
Surface Hardness ◽  
High Hardness ◽  
Carbon Steels ◽  
Alloying Elements ◽  
Low Carbon ◽  
Surface Alloying ◽  
Operating Life ◽  
Resistance To Wear

The alloying elements W-Mo cementation is carried out on the surfaces of low carbon steels by the technique of plasma metallurgy. Then by using the plasma-supersaturated carbonization, the composition of surface alloying layer reaches or approaches that of low-alloy HSS. In the end the surface alloying layer possesses high hardness, favorable red hardness and a significant improvement in properties after high temperature quenching and high temperature tempering. The surface cementation structure and phase structure of alloying layer were analyzed using metallographic microscope and X-ray diffraction (XRD), respectively; the distribution of surface composition and hardness of the layer were investigated by Glow Discharge Analytical Instrument (GDA) and micro hardness instrument, respectively; the resistance to wear was tested by a abrasion machine. The experimental results indicated that the layer consisted of W-Mo solid solution in Fe, the depth of the layer could reach 100µm and the content of tungsten exceeded 10% after ion W-Mo cementation. The carbon content of carburized layer was 1.3% above, which was composed of M6C carbide containing a lot of elements of W-Mo. The surface hardness of the alloying layer attained the HV1000 or so and appeared graded distribution after quenching and tempering. The application study showed that alloying elements W-Mo cementation was an appropriate technique to enhance surface resistance to wear and prolong operating life of accessories.

Increasing Hardness of Surface Layer of Low-Carbon Steel by Account of Plasma Treatment of Coating Modification

2021 ◽  
Vol 316 ◽  
pp. 794-802
Author(s):  
Andrey E. Balanovsky ◽  
Van Trieu Nguyen
Keyword(s):  
Surface Layer ◽  
Thermal Treatment ◽  
Plasma Treatment ◽  
Plasma Heating ◽  
High Surface ◽  
Surface Hardness ◽  
High Hardness ◽  
Diffusion Region ◽  
Low Carbon ◽  
Wide Range

The Purpose of paper is to conduct studies to assess the possibility of increasing the hardness of the surface layer of steel St3 grade by plasma heating of the applied surface coating containing powder alloy PR-N80X13S2R. Mixtures of pasta were divided into 2 groups: for furnace chemical-thermal treatment and plasma surface melting. The study of the microstructure showed a difference in the depth of the saturated layer, depending on the processing method, during chemical-thermal treatment-1 mm, plasma fusion - 2 mm. The results of measuring the surface micro-hardness showed that, the obtained coating from a mixture of PR-N80X13S2R + Cr2O3 + NH4Cl has a uniform high surface hardness (31-64 HRC), from a mixture of only PR-N80X13S2R - the surface hardness varies in a wide range (15-60 HRC). The study of the microhardness of the cross section of the surface layer showed that, the diffusion region: from a mixture of powder PR-N80X13S2R + Cr2O3 + NH4Cl has uniform hardness (450-490 HV); from a mixture of PR-N80X13S2R - hardness increases in the depth of the molten region (from 300 to 600 HV), and sharply decreases in the heat affected zone (210-170 HV). The use of PR-N80X13S2R alloy powder as the main component in the composition of the paste deposited on the St3 surface during plasma treatment leads to the formation of a doped surface layer with high hardness.

scholarly journals The Effect of S and Mn on the High-temperature Oxidation and Scale Spallation Behavior of Low-carbon Steels

2009 ◽  
Vol 49 (12) ◽  
pp. 1938-1944 ◽  
Author(s):  
Shigenari Hayashi ◽  
Takeshi Sekimoto ◽  
Kazuhiko Honda ◽  
Takeshi Kinoshita ◽  
Kazuaki Tanaka ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Carbon Steels ◽  
Low Carbon ◽  
Scale Spallation ◽  
Temperature Oxidation ◽  
Low Carbon Steels

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.

High Temperature Corrosion of Al Hot-Dipped Low Carbon Steels in N2/H2S-Mixed Gases

2016 ◽  
Vol 369 ◽  
pp. 59-64
Author(s):  
Muhammad Ali Abro ◽  
Dong Bok Lee
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Alloy Layer ◽  
High Temperature Corrosion ◽  
Carbon Steels ◽  
Low Carbon ◽  
Mixed Gas ◽  
Low Carbon Steels ◽  
Mixed Gases

A low carbon steel was hot-dip aluminized, and corroded in the N2/0.4%H2S-mixed gas at 650-850°C for 20-50 h in order to find the effect of aluminizing on the high-temperature corrosion of the low carbon steel in the H2S environment. A thin Al topcoat and a thick Al-Fe alloy layer that consisted primarily of Al5Fe2 and some FeAl and Al3Fe formed on the surface after aluminizing. The corrosion rate increased with an increase in temperature. Hot-dip aluminizing increased the corrosion resistance of the carbon steel through forming a thin protective α-Al2O3 scale on the surface. The α-Al2O3 scale was susceptible to spallation. During corrosion, internal voids formed in the Al-Fe alloy layer, where the Al5Fe2, AlFe, and Al3Fe compounds gradually transformed through interdiffusion.

Experimental Study of Laser Surface Treatment of Low-Carbon Ductile Iron

2012 ◽  
Vol 155-156 ◽  
pp. 965-968
Author(s):  
Yu Zhong Li ◽  
Jing Ping Liu
Keyword(s):  
Surface Treatment ◽  
Ductile Iron ◽  
Surface Hardness ◽  
Laser Surface ◽  
Low Carbon ◽  
Surface Alloying ◽  
Laser Surface Treatment ◽  
Iron Matrix ◽  
Laser Surface Alloying ◽  
Surface Laser

In the essay, the Low carbon ductile iron by laser surface alloying processing has been experimentally studied. Results indicate that on low carbon ductile iron matrix coated with different alloy powder, structure of laser surface alloying processing is very small, the combination quality between alloying layer and matrix is good. Low carbon ductile iron after laser surface treatment, maternal surface hardness are greatly enhanced, maternal surface hardness increasing from HV250~330 to the highest about HV1400, surface laser hardening effect of Low carbon ductile iron is very obvious.

scholarly journals Boron Steel: An Alternative for Costlier Nickel and Molybdenum Alloyed Steel for Transmission Gears

2010 ◽  
Vol 8 (1) ◽  
pp. 12 ◽  
Author(s):  
A. Verma ◽  
K. Gopinath ◽  
B. Sarkar
Keyword(s):  
Mechanical Properties ◽  
Precipitation Hardening ◽  
Carbon Steels ◽  
Alloyed Steel ◽  
Alloying Elements ◽  
Boron Steel ◽  
Low Carbon ◽  
Low Carbon Steels

 Case Carburized (CC) low carbon steels containing Ni, Cr and Mo alloying elements are widely used for transmission gears in automobile, as it possesses desired mechanical properties. In order to cut cost and save scarce materials like Ni and Mo for strategic applications, steel alloyed with Boron has been developed, which gives properties comparable to Ni-Cr-Mo alloyed steel. In the process of steel development, care was taken to ensure precipitation of boron which results in precipitation hardening. The characterization of the developed boron steel had exhibited properties comparable to Ni-Cr-Mo alloyed steel and superior to conventional boron steel. 

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