scholarly journals Effect of QPQ treatment on the performance for H13 die steel

2017 ◽  
Vol 23 (3) ◽  
pp. 251
Author(s):  
Shijing Lu ◽  
Fanna Meng ◽  
Wei Cai ◽  
Wei Wei ◽  
Jing Hu

<p class="AMSmaintext">QPQ salt bath treatment of H13 steel was conducted by nitriding at the same temperature of 565℃ for various times, followed by the same post-oxidation process. Optical microscope, micro-hardness tester, X-ray diffraction and wear resistance tester were employed to characterize the microstructure, phase constituents, micro-hardness and wear resistance of the treated specimens. The results showed a compound layer mainly composed of ε-Fe<sub>2-3</sub>N and diffusion layer were formed during salt bath nitriding and a thin oxide layer composed of Fe<sub>3</sub>O<sub>4</sub> was formed by post-oxidation, and the compound layer thickness increases with the nitriding time. The maximum surface hardness value of 1441HV<sub>0.3</sub>was obtained after nitriding at 565℃ for 150min, which is as three times high as that of untreated sample. Meanwhile the wear resistance of H13 steel is significantly improved by QPQ treatment, 150min is the optimum nitriding time to improve the surface hardness and wear resistance of H13 steel.</p>

2010 ◽  
Vol 97-101 ◽  
pp. 1454-1458 ◽  
Author(s):  
Guang Yao Xiong ◽  
Ming Juan Zhao ◽  
Long Zhi Zhao ◽  
Zhang Jian

The structure and properties of H13 steel treated by the QPQ Salt-bath treatment with different content of Rare Earth (RE) LaCO3 were studied. The surface of H13 steel was treated using this method. The microstructure and depth of the treated surface for the steel were analyzed using SEM. The sliding wear resistance was tested on the M-2000 tester and the micro-hardness was tested using 401MVA microscopy hardness tester. The results showed that the thickness and the wear resistance and the speed of nitriding was highly improved and the performance of nitriding layer and the nitriding structure was improved.


2019 ◽  
Vol 25 (2) ◽  
pp. 130
Author(s):  
Wenchen Mei ◽  
Jiqiang Wu ◽  
Mingyang Dai ◽  
Kunxia Wei ◽  
Jing Hu

<p class="AMSmaintext1">Salt bath preoxidation was primarily conducted prior to salt bath nitriding, and the effect on salt bath nitriding was compared with that of conventional air preoxidation. Characterization of the modified surface layer was made by means of optical microscopy, scanning electron microscope (SEM), micro-hardness tester and x-ray diffraction (XRD). The results showed that the salt bath preoxidation could significantly enhance the nitriding efficiency. The thickness of compound layer was increased from 13.3μm to 20.8μm by salt bath preoxidation, more than 60% higher than that by conventional air preoxidation under the same salt bath nitriding parameters of 560℃ and 120min. Meanwhile, higher cross-section hardness and thicker effective hardening layer were obtained by salt bath preoxidation, and the enhancement mechanism of salt bath preoxidation was discussed.</p>


2014 ◽  
Vol 1030-1032 ◽  
pp. 259-262 ◽  
Author(s):  
Hai Yang ◽  
Ren Bao Jiao ◽  
Shu Yang Wang

To improve the harrow disk made of 65Mn steel working life, an ion implanting metal in order to obtain tungsten carbide treatment was proposed in this work. Microstructure and phase composition of 65Mn steel obtained by ion implanting tungsten carbide process were analyzed by optical microscope and XRD, respectively. The surface hardness was tested by microscopic hardness tester, and the wear resistant performance of the wear layer was tested by abrader abrasor. The results showed that the micro-hardness of ion implanting tungsten carbide layer can be reached 1100 HV0.2, higher than that of 65Mn steel, the thickness of tungsten carbide layer was 400μm, which greatly improve the wear resistance. Harrow disk after the ion implanting tungsten carbide exhibited the excellent wear resistance in the sandy soil, and its working life was more than twice the length of the genera treatment harrow disk.


2020 ◽  
Vol 26 (1) ◽  
pp. 4-6
Author(s):  
Xiliang LIU ◽  
Changjun MAO ◽  
Meihong WU ◽  
Wei CAI ◽  
Mingyang DAI ◽  
...  

In this study, salt bath nitriding was carried out at 565℃ for various times for 304 stainless steel (304SS). The effect of salt bath nitriding time on the microstructure, micro-hardness and wear resistance was investigated systematically. The results showed a nitriding layer was formed during salt bath nitriding, and the thickness of effective hardening layer is duration dependant. The maximum microhardness value of 1200HV0.01 was obtained at optimal duration of 150min, which was five times higher than that of the untreated sample. And the wear resistance could be significantly improved by salt bath nitriding, the lowest weight loss after wear resistance was obtained while nitriding for 150min, which was one tenth of that of untreated sample.


2019 ◽  
Vol 26 (07) ◽  
pp. 1850217 ◽  
Author(s):  
O. ÇOMAKLI ◽  
A. F. YETIM ◽  
B. KARACA ◽  
A. ÇELIK

The 31CrMoV9 steels were plasma nitrided under different gas mixture ratios to investigate an influence of nitrogen amount on wear behavior. The structure, mechanical and tribological behavior of untreated and nitrided 31CrMoV9 steels were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), microhardness device, 3D profilometer and pin-on-disk wear tester. The analysis outcomes displayed that the compound layer consists of nitride phases (Fe2N, Fe3N, Fe4N and CrN). Additionally, the thickness of the compound layers, surface hardness and roughness increased with increasing nitrogen amount in the gas mixture. The highest friction coefficient value was obtained at nitrogen amount of 50%, but the lowest value was seen at nitrogen amount of 6%. It was observed that wear resistance of 31CrMoV9 steel improved after plasma nitriding, and the best wear resistance was also obtained from plasma nitrided sample at the gas mixture of 94% H[Formula: see text]% N2.


2016 ◽  
Vol 840 ◽  
pp. 331-335
Author(s):  
Nur Amira Mohd Rabani ◽  
Zakiah Kamdi

Cemented tungsten carbides have been paid much attention due its better mechanical properties with excellent combination of hardness and toughness characteristics. The hard WC particles in the coating provide hardness and wear resistance, while the ductile binder such as Co and Ni contribute to toughness and strength. WC-17wt.% Co and WC-9wt.% Ni powders have been sprayed by the HVOF method to form coatings approximately 300μm and 150μm thick onto AISI 1018 steel substrate. Both coatings have been prepared and supplied by an external vendor. The coatings were examined using optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The hardness of both coatings were also measured using Vickers micro-hardness tester. The microstructure of the coatings has been analyzed and found to consist of WC, brittle W2C phase, metallic W phase, and amorphous binder phase of Co and Ni. It is found that WC-Ni has a higher hardness value compared to WC-Co due to high porosity distribution.


2011 ◽  
Vol 69 ◽  
pp. 93-98
Author(s):  
Xiao Dong Zhang ◽  
Bin Shi Xu ◽  
Shi Yun Dong ◽  
Zhi Jian Wang ◽  
Han Shan Dong ◽  
...  

In order to enhance the performances of laser remanufacturing part, we combined laser cladding with active screen plasma nitriding duplex treatment to repair metal part. The microstructure, phase structure and micro-hardness of duplex treated coating were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and micro-hardness tester. Wear tests were carried out on reciprocating wear tester under dry sliding condition. The results show that the white layer and the nitrogen diffusion layer were formed after nitriding treatment. The duplex treated coating consists mainly of γ-Fe, CrN, Fe4N and Fe3N. The duplex treated coating improved not only surface hardness but also wear resistance.


2018 ◽  
Vol 24 (3) ◽  
pp. 229
Author(s):  
Lu Song ◽  
Tiantian Peng ◽  
Xiaobin Zhao ◽  
Jing Hu

<p class="AMSmaintext">Critical nitrogen hydrogen ratio in plasma nitriding was primarily investigated to get enhanced performance for 38CrMoAl steel. The modified surface layer was characterized by optical microscopy (OM), X-ray diffraction (XRD) and micro-hardness tester. The results showed that the critical nitrogen hydrogen ratio was 1: 5 while plasma nitriding at 540℃ for 6 h. Under this condition, no compound layer was formed, and accompanied with high surface hardness, while the compound layer was formed accompanied with lower surface hardness with nitrogen hydrogen ratio higher than the critical value.</p>


2012 ◽  
Vol 538-541 ◽  
pp. 235-238 ◽  
Author(s):  
Ren Guo Song ◽  
Pu Hong Tang ◽  
Chao Wang ◽  
Guo Lu

Al2O3 and Al2O3-40wt.%TiO2 ceramic coatings on H13 hot-worked die steel have been prepared by plasma spraying, and then the microstructure, micro-hardness as well as wear resistance of the prepared coatings have been investigated by means of x-ray diffraction (XRD), scanning electron microscope (SEM), Vickers hardness tester and ball-on-disk high temperature tribometer. The results showed that the plasma sprayed ceramic coatings are of higher hardness and wear resistance than H13 hot-worked die steel.


2017 ◽  
Vol 893 ◽  
pp. 340-344
Author(s):  
Sheng Dai ◽  
Dun Wen Zuo ◽  
Xian Rui Zhao ◽  
Jin Fang Wang

To improve the surface hardness and wear resistance of metal parts. Ni-based chromic carbidecomposite coating was prepared on the carbon steel (0.45 mass% C) substrates by laser cladding. Microstructure and wear properties of composite coatings were investigated by SEM, EDS, XRD, Vickers micro-hardness tester and wear machine. The results show that good metallurgical bonding between the Ni-based chromic carbidecomposite coating and carbon steel substrate. Micro-hardness of Ni-based Cr3C2 composite coating along the layer depth presents an evident stepladder distribution. The average micro-hardness of the laser clad coating is about 950 HV. The result of wear experiment shows that Ni-based Cr3C2 composite coating processes good wear resistance.


Sign in / Sign up

Export Citation Format

Share Document