Phase Composition and Thin Structure of Steel Surface after Plasma Electrolytic Carbonitriding

2020 ◽  
Vol 62 (10) ◽  
pp. 1794-1800
Author(s):  
N. A. Popova ◽  
A. I. Potekaev ◽  
E. L. Nikonenko ◽  
A. A. Klopotov ◽  
L. B. Bayatanova ◽  
...  
2020 ◽  
Author(s):  
M. V. Fedorischeva ◽  
M. P. Kalashnikov ◽  
I. A. Bozhko ◽  
V. P. Sergeev

2021 ◽  
Vol 23 (2) ◽  
pp. 147-162
Author(s):  
Undrakh Mishigdorzhiyn ◽  
◽  
Nikolay Ulakhanov ◽  
Aleksandr Tikhonov ◽  
Pavel Gulyashinov ◽  
...  

Introduction. Control and management of technological residual stresses (TRS) are among the most critical mechanical engineering technology tasks. Boriding can provide high physical and mechanical properties of machine parts and tools with minimal impact on the stress state in the surface layers. The purpose of this work is to determine the temperature modes of diffusion boriding, contributing to a favorable distribution of TRS in the surface layer of die steel 3Kh2V8F. The paper considers the results of studies on the TRS determination by the experimental method on the UDION-2 installation in diffusion layers on the studied steel surface. Boriding was carried out in containers with a powder mixture of boron carbide and sodium fluoride as an activator at a temperature of 950 °C and 1050 °C for 2 hours. The obtained samples of steels with a diffusion layer were examined using an optical microscope and a scanning electron microscope (SEM); determined the layers' microhardness, elemental, and phase composition. The experiments resulted in the following findings: as the boriding temperature rose from 950 °C to 1050 °C, the diffusion layer's thickness increased from 20 to 105 μm. The low-temperature mode of thermal-chemical treatment (TCT) led to the formation of iron boride Fe2B with a maximum boron content of 6 % and a microhardness up to 1250 HV. A high-temperature mode resulted in FeB formation with a top boron content of 11 % and a microhardness up to 1880 HV. Results and Discussions. It is found that boriding at 950 °C led to a more favorable distribution of compression TRS in the diffusion layer. However, significant TRS fluctuations in the diffusion layer and the adjacent (transitional) zone could affect the operational properties after TCT at a given temperature. An increase in the TCT temperature led to tensile TRS's appearance in the layer's upper zone at a depth of up to 50 μm from the surface. Despite tensile stresses on the diffusion layer surface after high-temperature TCT, the distribution of TCT is smoother than low-temperature boriding.


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.


2021 ◽  
Vol 8 (6) ◽  
pp. 974-989
Author(s):  
Jie Sun ◽  
◽  
Tzvetanka Boiadjieva-Scherzer ◽  
Hermann Kronberger ◽  

<abstract> <p>To imitate the superior biocompatibility of Ti–Zr alloys at reduced cost, conventional Ti6Al4V alloy was modified via plasma electrolytic oxidation (PEO). The influence of different additives on the phase composition and topography was investigated in acidic electrolytes containing Zr(SO<sub>4</sub>)<sub>2</sub>·H<sub>2</sub>O with potentiostatically controlled PEO at different pulse frequencies. Apart from the primary intention to generate Zr enriched phases, formation and incorporation in the ceramic layer of potential antibacterial Cu and Zn species was achieved and examined by X-ray diffraction. The thickness of the oxide layer, the adhesion and the layers' composition were evaluated using FIB and SEM-EDX.</p> </abstract>


2012 ◽  
Vol 55 (2) ◽  
pp. 57-59
Author(s):  
C. V. Gorbyunov ◽  
C. V. Vorob’ev ◽  
Yu. F. Ivanov ◽  
Yu. A. Kolubaeva ◽  
A. D. Terecov

2021 ◽  
Vol 871 ◽  
pp. 134-143
Author(s):  
Yin Hua Shi ◽  
Qin Shi

γ-Fe/(Cr, Fe)7C3 lamellar eutectics reinforced the composite coating was deposited onto the 16Mn steel surface to enhance its surface hardness and wear resistance. The microstructure, phase composition, microhardness as well as wear resistance of the cladding coating were explored. Results indicated that the coating showed the dense and defect-free metallurgical bonding with the substrate and mainly consisted of (Cr, Fe)7C3, γ-Fe/(Cr, Fe)7C3 lamellar eutectic, B4C and carbon fibers. (Cr, Fe)7C3, B4C and carbon fibers were tightly embedded in the γ-Fe/(Cr, Fe)7C3 lamellar eutectics matrix. The microhardness and wear resistance of the coating compared with that of the substrate were highly improved by nearly 5 and 3 times, respectively.


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