scholarly journals Studies on the Carburizing Process of AISI 8620 Steel Obtained by MIM Technology

2018 ◽  
Vol 19 (2) ◽  
pp. 70-76
Author(s):  
Dorin Ioan Feldiorean ◽  
◽  
Mircea Horia Țierean ◽  
Keyword(s):  
Carburizing Process ◽  
Mim Technology

scholarly journals Effects of Pre- and Post-Carburizing Surface Modification on the Tribological and Adhesion Properties of Heat-Resistant KHR 45A Steel for Cracking Tubes

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3658
Author(s):  
Auezhan Amanov ◽  
Joo-Hyun Choi ◽  
Young-Sik Pyun
Keyword(s):  
Surface Modification ◽  
Surface Treatment ◽  
Steel Substrate ◽  
Heat Exposure ◽  
Scratch Resistance ◽  
Adhesion Properties ◽  
Heat Resistant ◽  
Adhesion Behavior ◽  
Steel Substrates ◽  
Carburizing Process

In this study, the effects of ultrasonic nanocrystal surface modification (UNSM) technology on the tribological properties and scratch-induced adhesion behavior of a heat-resistant KHR 45A steel cracking tube, which is used for the pyrolysis process, were investigated. The main objective of this study is to investigate the effects of pre- and post-carburizing UNSM treatment on the tribological and adhesion performances of carburized domestic KHR 45A (A) steel and to compare the results with the existing carburized Kubota-made KHR 45A steel (B). A carburizing process was carried out on the polished and UNSM-treated KHR 45A steel substrates, which were cut out from the cracking tube, at 300 °C heat exposure for 300 h. The thickness of the carburizing layer was about 10 μm. UNSM technology was applied as pre- and post-carburizing surface treatment; both reduced the friction coefficient and wear rate compared to that of the carburized KHR 45A steel substrate. It was also found that the application of UNSM technology increased the critical load, which implies the improvement of adhesion behavior between the carburizing layer and the KHR steel substrate. The application of UNSM technology as pre- and post-carburizing surface treatment could help replace carburized Kubota-made KHR 45A steel (B) thanks to the improved tribological performance, enhanced scratch resistance, load bearing capacity, and adhesion of domestic KHR 45A (A) steel.

scholarly journals Acetylene Flow Rate as a Crucial Parameter of Vacuum Carburizing Process of Modern Tool Steels

2016 ◽  
Vol 61 (4) ◽  
pp. 2009-2012 ◽  
Author(s):  
P. Rokicki ◽  
K. Dychton
Keyword(s):  
Chemical Treatment ◽  
Negative Impact ◽  
Aerospace Industry ◽  
Tool Steels ◽  
Vacuum Carburizing ◽  
Layer Characteristic ◽  
Process Methodology ◽  
Carburized Layer ◽  
Treatment Procedures ◽  
Carburizing Process

Abstract Carburizing is one of the most popular and wide used thermo-chemical treatment methods of surface modification of tool steels. It is a process based on carbon diffusive enrichment of the surface material and is applied for elements that are supposed to present higher hardness and wear resistance sustaining core ductility. Typical elements submitted to carburizing process are gears, shafts, pins and bearing elements. In the last years, more and more popular, especially in highly advanced treatment procedures used in the aerospace industry is vacuum carburizing. It is a process based on chemical treatment of the surface in lower pressure, providing much higher uniformity of carburized layer, lower process cost and much lesser negative impact on environment to compare with conventional carburizing methods, as for example gas carburizing in Endo atmosphere. Unfortunately, aerospace industry requires much more detailed description of the phenomena linked to this process method and the literature background shows lack of tests that could confirm fulfilment of all needed requirements and to understand the process itself in much deeper meaning. In the presented paper, authors focused their research on acetylene flow impact on carburized layer characteristic. This is one of the most crucial parameters concerning homogeneity and uniformity of carburized layer properties. That is why, specific process methodology have been planned based on different acetylene flow values, and the surface layer of the steel gears have been investigated in meaning to impact on any possible change in potential properties of the final product.

Effect of Soaking Time on Paste Carburizing of Carburized Low Carbon Steel

2017 ◽  
Vol 740 ◽  
pp. 93-99
Author(s):  
Muhammad Hafizuddin Jumadin ◽  
Bulan Abdullah ◽  
Muhammad Hussain Ismail ◽  
Siti Khadijah Alias ◽  
Samsiah Ahmad
Keyword(s):  
Carbon Steel ◽  
Carbon Content ◽  
Low Carbon Steel ◽  
Case Depth ◽  
Carbon Steels ◽  
Low Carbon ◽  
Soaking Time ◽  
Low Carbon Steels ◽  
Carburized Steel ◽  
Carburizing Process

Increase of soaking time contributed to the effectiveness of case depth formation, hardness properties and carbon content of carburized steel. This paper investigates the effect of different soaking time (7-9 hours) using powder and paste compound to the carburized steel. Low carbon steels were carburized using powder and paste compound for 7, 8 and 9 hours at temperature 1000°C. The transformation of microstructure and formation carbon rich layer was observed under microscope. The microhardness profiles were analyzed to investigate the length of case depth produced after the carburizing process. The increment of carbon content was considered to find the correlation between types of carburizing compound with time. Results shows that the longer carburized steel was soaked, the higher potential in formation of carbon rich layer, case depth and carbon content, which led to better hardness properties for carburized low carbon steel. Longer soaking time, 9 hours has a higher dispersion of carbon up to 41%-51% compare to 8 hours and 7 hours. By using paste carburizing, it has more potential of carbon atom to merge the microstructure to transform into cementite (1.53 wt% C) compare to powder (0.97 wt% C), which increases the hardness of carburized steel (13% higher).

scholarly journals Development of feedstock of tungsten-nickel-iron- polyformaldehyde for MIM technology

2016 ◽  
Vol 156 ◽  
pp. 012033 ◽  
Author(s):  
D V Kostin ◽  
A V Parkhomenko ◽  
A P Amosov ◽  
A R Samboruk ◽  
A V Chemashkin
Keyword(s):  
Nickel Iron ◽  
Mim Technology

Studies on the Influence of Sintering Parameters on the Hardness and Impact Energy of Some Sintered Steels Alloyed with Copper Powders

2015 ◽  
Vol 1128 ◽  
pp. 80-87
Author(s):  
Claudiu Nicolicescu ◽  
Iulian Ştefan ◽  
Victor Horia Nicoară
Keyword(s):  
Experimental Research ◽  
Impact Energy ◽  
Copper Content ◽  
Argon Atmosphere ◽  
Experimental Results ◽  
Sintered Steels ◽  
Copper Powders ◽  
Carburizing Process

The paper presents experimental results regarding the evolution of hardness and impact energy of some sintered steels alloyed with 1.5% respective 3% (weight) copper powders. For the experimental research were used 3 mixtures: Fe+0.2C as reference, Fe+0.2C+1.5Cu, Fe+0.2C+3Cu. All the samples were die pressed at three pressures 400, 500 and 600 MPa and were subjected at three types of treatments as following: SINT, SINTCARB and CARBSINT. For the sintering treatments was used argon atmosphere and for carburizing process was used methane. After each treatment the hardness and impact energy for all the samples were measured and were made correlations between these properties and the type of treatment and copper content.

Numerical Solution of the Differential Diffusion Equation for a Steel Carburizing Process

2018 ◽  
Vol 284 ◽  
pp. 1230-1234
Author(s):  
Mikhail V. Maisuradze ◽  
Alexandra A. Kuklina
Keyword(s):  
Diffusion Equation ◽  
Numerical Solution ◽  
Differential Diffusion ◽  
One Dimensional ◽  
The Third ◽  
Dimensional Diffusion ◽  
Simplified Algorithm ◽  
The One ◽  
Carburizing Process ◽  
Precise Assessment

The simplified algorithm of the numerical solution of the differential diffusion equation is presented. The solution is based on the one-dimensional diffusion model with the third kind boundary conditions and the finite difference method. The proposed approach allows for the quick and precise assessment of the carburizing process parameters – temperature and time.

Process of Shaped Metal Billets Production from Compositions Based on Iron Powder, Iron Oxide, and Binder

2017 ◽  
Vol 265 ◽  
pp. 250-258
Author(s):  
V.A. Dovydenkov ◽  
O.S. Zvereva ◽  
S.Ya. Alibekov
Keyword(s):  
Iron Oxide ◽  
Thermal Treatment ◽  
Solid Phase ◽  
New Technology ◽  
Physical And Mechanical Properties ◽  
Dimensional Accuracy ◽  
Uniform Density ◽  
Protective Medium ◽  
Experimental And Theoretical Studies ◽  
Mim Technology

A new technology of metal billets production by molding and thermal treatment of compositions based on iron powders of medium dispersion, fine powders of iron oxide, and the thermosetting binder, which provides for the required physical and mechanical properties of the material, is proposed. It is found that, at a certain concentration and dispersion of the components of the solid phase, the injection and direct compression molding of parts of complex shape (similar to the MIM-technology) is possible at pressures from 70 MPa to 100 MPa ensuring uniform density over the cross section. The established stages of thermal treatment of compositions, thermal behavior and protective medium ensuring uniformity of products, and chemical composition of the product material are presented in the paper. The experimental and theoretical studies of the dimensional accuracy of steel products obtained by the developed technology were carried out, and it was discovered that the produced parts were of the precision of steel parts produced by MIM-technology.

Hardness Distribution and Effective Case Depth of Low Carbon Steel after Pack Carburizing Process under Different Carburizer

2015 ◽  
Vol 776 ◽  
pp. 201-207 ◽  
Author(s):  
Dewa Ngakan Ketut Putra Negara ◽  
I. Dewa Made Krisnha Muku ◽  
I. Ketut Gede Sugita ◽  
I. Made Astika ◽  
I. Wayan Mustika ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Case Depth ◽  
Bamboo Charcoal ◽  
Hardness Distribution ◽  
Low Carbon ◽  
Bone Charcoal ◽  
Carburizing Process ◽  
Effective Case Depth ◽  
Effective Case

This research is concerned with the effect of different carburizers on hardness distribution, effective case depth and microstructure of low carbon steel after pack carburizing process. Carburizers to be used were combination of energizer (BaCO3), goat bone charcoal and bamboo charcoal with five different compositions. The specimens were heated to temperature of 950°C, soaked at the temperature for 4 hours and quenched in the water. After the process, microstructures of specimen were observed, the hardness was measured using Vikers method and effective case depths were calculated. The results obtained showed that for all types of carburizer used, the hardness were scattered from surface to the core with lower hardness level. Carburizer composition of 20% BaCO3 + 80% goat bone charcoal produced the highest hardness ( 789.273 HV1) at 0.2 mm from the surface, however, it yielded the lowest effective case depth (0.52 mm). The highest effective case depth of 1 mm was obtained using carburizer composition of 20% BaCO3 + 60% goat bone charcoal + 20% bamboo charcoal. Meanwhile, the original structures of raw material which consist of ferrite and pearlite transformed to hard martensite constituent in the surface after pack carburizing.

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