Influence of layer substrate hardening on nitrided carbon steels on their tribological properties

2018 ◽  
Vol 24 (3) ◽  
pp. 50-54
Author(s):  
Jan Senatorski ◽  
Jan Tacikowski ◽  
Janusz Trojanowski ◽  
Paweł Mączyński

Nitriding of carbon steels does not allow for adequate hardening of the substrate of layers and core required in some applications. Such hardening can be achieved by using further heat treatment. As a result of this heat treatment, the zone of nitrides vanishes and a nitro-carbon martensite structure is formed, additionally hardened by ageing. The carried out tribological tests have shown that subjecting nitrided carbon steel to further hardening treatment significantly improves its wear resistance in comparison to nitrided steel, and the zone of good wear resistance goes deeper.

2018 ◽  
Vol 27 (47) ◽  
pp. 101
Author(s):  
Sandra Arias ◽  
Maryory Gómez ◽  
Esteban Correa ◽  
Félix Echeverría-Echeverría ◽  
Juan Guillermo Castaño

Nickel-Boron autocatalytic coatings are widely used in several industries to improve mechanical properties of materials such as hardness and wear resistance. Tribological properties were evaluated in Ni-B autocatalytic coatings deposited on AISI/SAE 1018 carbon steel before and after a heat treatment at 450 °C for one hour. Tribological tests were carried out by dry sliding, using a load of 5 N and a sliding speed of 0.012 m/s, in a homemade ball-on-disk tribometer, which followed ASTM G99 standard. According to the tribological evaluation, the heat treatments applied to Ni-B coatings improved their tribological performance. This research corroborates that by applying an adequate heat treatment, hardness and wear resistance of Ni-B coatings can be improved significantly.


Author(s):  
S. I. Bogodukhov ◽  
E. S. Kozik ◽  
E. V. Svidenko

Hard alloys are popular materials widely used in the toolmaking industry. Refractory carbides included in their composition make carbide tools very hard (80 to 92 HRA) and heat-resistant (800 to 1000 °С) so as they can be used at cutting speeds several times higher than those used for high-speed steels. However, hard alloys differ from the latter by lower strength (1000 to 1500 MPa) and the absence of impact strength, and this constitutes an urgent problem. We studied the influence of thermal cycling modes on the mechanical and tribological properties of VK8 (WC–8Co) hard alloy used in the manufacture of cutters and cutting inserts for metal working on metal-cutting machines. As the object of study, we selected 5×5×35 mm billets made of VK8 (WC–8Co) alloy manufactured by powder metallurgy methods at Dimitrovgrad Tool Plant. The following criteria were selected for heat treatment mode evaluation: Vickers hardness, flexural strength, and mass wear resistance (as compared to the wear of asreceived samples that were not heat treated). Plates in the initial state and after heat treatment were subjected to abrasion tests. Wear results were evaluated by the change in the mass of plates. Regularities of the influence of various time and temperature conditions of heat treatment on the tribological properties of products made of VK group tungsten hard alloys were determined. An increase in the number of thermal cycling cycles improved such mechanical properties of the VK8 hard alloy as strength and hardness. When repeating the cycles five times, an increase in abrasive wear resistance was obtained compared to the initial nonheat-treated sample. The elemental composition of the VK8 hard alloy changed insignificantly after thermal cycling, only a slight increase in oxygen was observed on the surface of plates. The grain size after thermal cycling increased in comparison with the initial VK8 hard alloy. It was found that VK8 hard alloy thermocyclic treatment leads to a change in the phase composition. X-ray phase analysis showed the presence of a large amount of α-Co with an hcp-type lattice on the surface of a hard alloy and a solid solution of WC in α-Co. A change in the cobalt modification ratio causes a decrease in microstresses. An analysis of the carbide phase structure state showed that the size of crystallites and microstresses changed after thermal cycling. The lattice constant of the cobalt cubic solid solution decreased, which may indicate a decrease in the amount of tungsten carbide and carbon dissolved in it. Statistical processing of experimental results included the calculation of the average value of the mechanical property, its dispersion and standard deviation in the selected confidence interval.


1972 ◽  
Vol 8 (10) ◽  
pp. 938-939
Author(s):  
S. M. Gadzhibeklinskii ◽  
K. T. Aliev ◽  
Ya. B. Shlimak ◽  
D. I. Agamirzoev

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yuh-Ping Chang ◽  
Jin-Chi Wang ◽  
Jeng-Haur Horng ◽  
Li-Ming Chu ◽  
Yih-Chyun Hwang

The technology of composite heat treatment is used popularly for low friction and wear resistance of drive elements. A large number of papers about the heat treatment technology had been proposed. Especially, the nitride treatment has been used widely for the purpose of wear resistance and low friction in the industry. Therefore, the self-developed vertical ball/disk friction tester with the measurement system was used to study the effects of nitride on the tribological properties of the low carbon alloy steel—SCM415— in this study. The experiments were conducted under dry and severe wear conditions. The variations of friction coefficient and surface magnetization were simultaneously recorded during dynamic friction process. After each test, the microstructures of the wear particles were observed and analyzed under a SEM, and the depth of wear track is measured by means of a surface tester. According to the experimental results, the wear resistance of the specimens with carburizing-nitride is significantly larger than the case of nitride-carburizing. Moreover, the surface magnetization was especially larger for the case of nitride-carburizing. As a result, the wear particles always stay in the interfaces and the wear mechanism becomes complex. Therefore, it is necessary to put nitride after carburizing for the composite heat treatments.


Author(s):  
D. Mikołajczak ◽  
M. Kulka ◽  
N. Makuch ◽  
P. Dziarski

Purpose: The aim of the study was to improve the hardness and tribological properties of austenitic 316L steel by laser alloying with boron and nickel. Design/methodology/approach: The relatively low wear resistance of austenitic 316L steel could be improved by an adequate surface treatment. Laser alloying was developed as an alternative for time- and energy-consuming thermo-chemical treatment, e.g. diffusion boriding. In the present study, laser alloying of 316L steel with boron and nickel was carried out as the two-stage process. Firstly, the outer surface of the sample was coated with the paste, consisting of the mixture of boron and nickel powders, blended with a diluted polyvinyl alcohol solution. Second stage consisted in laser re-melting of the paste coating together with the base material. Laser treatment was carried out with the use of the TRUMPF TLF 2600 Turbo CO2 laser. The multiple laser tracks were formed on the surface. The microstructure was observed with the use of an optical microscope (OM) and scanning electron microscope (SEM) Tescan Vega 5135. The phase analysis was carried out by PANalytical EMPYREAN X-ray diffractometer using Cu Ka radiation. Hardness profile was determined along the axis of laser track. Wear resistance was studied using MBT-01 tester. Findings: The use of the adequate laser processing parameters (laser beam power, scanning rate, overlapping) caused that free of cracks and gas pores and the uniform laseralloyed layer in respect of the thickness was produced. In the microstructure, only two zones were observed: laser re-melted zone (MZ) and the substrate. There were no effects of heat treatment below MZ. Heat-affected zone (HAZ) was invisible because the austenitic steel could not be hardened by typical heat treatment (austenitizing and quenching). The produced laser-alloyed layer was characterized by improved hardness and wear resistance compared to the base material. Research limitations/implications: The application of proposed surface treatment in industry will require the appropriate corrosion resistance. In the future research, the corrosion behaviour of the produced layer should be examined and compared to the behaviour of 316L steel without surface layer. Practical implications: The proposed layer could be applied in order to improve the hardness and tribological properties of austenitic steels. Originality/value: This work is related to the new conception of surface treatment of austenitic steels, consisting in laser alloying with boron and some metallic elements.


2014 ◽  
Vol 66 (5) ◽  
pp. 609-617 ◽  
Author(s):  
De-Xing Peng ◽  
Yuan Kang ◽  
Yu-Jun Huang

Purpose – The purpose of this paper is to evaluate the wear performance of carbon steel cladded with TiC powders by gas tungsten arc welding method. Because of poor wear resistance, carbon steels have limited industrial applications as tribological components. Design/methodology/approach – The cladding microstructures were characterized by optical microscope, scanning electron microscope (SEM) and X-ray energy dispersive spectrometer. The wear behavior of the clad layer was studied with a block-on-ring tribometer. Findings – The experimental results revealed that the metallurgical interface provided an excellent bond between the cladding and the carbon steel substrate. The cladding revealed no porosity or cracking, and particles were evenly distributed throughout the cladding layer. Hardness was increased from HRc 6.6 in the substrate to HRc 62 in the cladded layer due to the presence of the hard TiC phase. Originality/value – The experiments confirm that the cladding surfaces of TiC particles reduce wear rate and friction. Increasing TiC contents also improves hardness and wear resistance at room temperature and under dry sliding wear conditions.


2021 ◽  
Vol 2 (1) ◽  
pp. 48-54
Author(s):  
Bahodir Kurbanovich Tilabov ◽  
◽  
Zulkhumor Latipovna Alimbabayeva

The article presents research materials on thestructure and properties of hard-alloy coatings obtained in the process of casting products using gasified models. The composition and properties of steel were studied, as well as the hardness and microhardness of the surface and subsurface layers of castparts. The relative wear resistance of tests performed in laboratory and field conditions is analyzed. The final modes of heat treatment with double phase recrystallization for cast parts are carried out. It is shown that heat treatment with double phase recrystallization increases the wear resistance of hard-alloy coatings and finished products by 3-4 times.Keywords: gasified model Casting, hard-alloy coating, high-carbon steel, hardness and microhardness, microstructure, heat treatment with double phase recrystallization, abrasive wear resistance and durability


2006 ◽  
Vol 129 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Ping Huang ◽  
Rong Liu ◽  
Xijia Wu ◽  
Matthew X. Yao

The chemical composition of Stellite® 21 alloy was modified by doubling the molybdenum (Mo) content for enhanced corrosion and wear resistance. The specimens were fabricated using a casting technique. Half of the specimens experienced a heat treatment at 1050°C for an hour. The microstructure and phase analyses of the specimens were conducted using electron scanning microscopy and X-ray diffraction. The mechanical properties of the specimens were determined in terms of the ASTM Standard Test Method for Tension Testing of Metallic Materials (E8-96). The mechanical behaviors of individual phases in the specimen materials were investigated using a nano-indentation technique. The wear resistance of the specimens was evaluated on a ball-on-disk tribometer. The experimental results revealed that the increased Mo content had significant effects on the mechanical and tribological properties of the low-carbon Stellite® alloy and the heat treatment also influenced these properties.


2019 ◽  
Vol 34 ◽  
pp. 10-17
Author(s):  
Adriana Zara ◽  
Maria Stoicănescu ◽  
I. Giacomelli

Usage of electron beam shows the possibility of using its energy in different thermic processes. Among these, it is found the heating of mechanical products for the surface heat treatment. During the effectuated practical attempts, two types of construction steels were analyzed, namely carbon steel (OLC 45) and a low alloyed steel (41 Cr 4). The electron beam was applied on samples that were previous subjected to the heat treatment of improvement. The working parameters were chosen in order to obtain the heating of the superficial layer without melting. The samples treated as above were subjected to studies regarding the metallographic structures and the resulted hardness; also there were effectuated wear attempts. It was concluded that the use of electron beam in superficial heat treatment may also fit in practical terms.


2013 ◽  
Vol 311 ◽  
pp. 477-481
Author(s):  
Yuh Ping Chang ◽  
Huann Ming Chou ◽  
Jeng Haur Horng ◽  
Li Ming Chu ◽  
Zi Wei Huang

The bad quality of machining surfaces caused by the micro wear of pressing parts has been a very big trouble for the engineers over the past decades. In order to decrease the surface wear, the technology of heat treatment is used popular. Many papers about the heat treatment technology had been proposed. Especially, the deep cryogenic treatment has been used widely for the purpose of wear-resistance in the industry. Moreover, the method of using variations of surface magnetization to monitor the dynamic tribological properties between the metal pairs has been applied successfully by the author. Therefore, this paper is base on the above statements to further investigate the tribological properties of the tool steel by deep cryogenic treatment. It can be clarified for effects of different deep cryogenic treatment temperatures on wear-resistance of the tool steel DC53. Besides, the purpose of better quality and faster product speed of the pressing process can then be obtained.


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