Influence of QPQ Salt Bath Composite Processing on Microstructure and Property of a Certain Type Aviation Piston Engine Ring

2015 ◽  
Vol 751 ◽  
pp. 26-29
Author(s):  
Jun Wen Lu ◽  
Qian Ying Wang ◽  
Bo Zheng
Keyword(s):  
Wear Resistance ◽  
Hardness Test ◽  
Complex Salt ◽  
Compound Layer ◽  
Salt Bath ◽  
Micro Hardness ◽  
Piston Engine ◽  
Untreated Sample ◽  
Modified Surface

QPQ salt bath treatment of a certain type aviation piston engine ring was conducted by nitriding (570°C, 180 min), followed by the post-oxidation process (400°C, 20 min), polishing, the second post-oxidation (370°C, 20 min). Characterization of modified surface layers was made by means of optical microscopy, micro-hardness test, corrosion and wear resistance test. The results showed the formation of a very thin oxide layer during post-oxidation on the top of the black nitrides compound layer formed during nitriding. The maximum micro-hardness value of 592 HV was obtained after nitriding at 570°C for 180 min, which was nearly twice higher than that of the untreated sample. The wear resistance of ring could be significantly improved by QPQ complex salt bath treatment, which is almost 5 times higher than that of the untreated sample.

scholarly journals COMPARISON OF SALT BATH PREOXIDATION AND AIR PREOXIDATION FOR SALT BATH NITRIDING

2019 ◽  
Vol 25 (2) ◽  
pp. 130
Author(s):  
Wenchen Mei ◽  
Jiqiang Wu ◽  
Mingyang Dai ◽  
Kunxia Wei ◽  
Jing Hu
Keyword(s):  
Compound Layer ◽  
Salt Bath ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Modified Surface ◽  
Salt Bath Nitriding ◽  
Modified Surface Layer

<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>

scholarly journals EFFECT OF SALT BATH NITRIDING TIME ON THE PERFORMANCES OF 304 STAINLESS STEEL

2020 ◽  
Vol 26 (1) ◽  
pp. 4-6
Author(s):  
Xiliang LIU ◽  
Changjun MAO ◽  
Meihong WU ◽  
Wei CAI ◽  
Mingyang DAI ◽  
...  
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Salt Bath ◽  
304 Stainless Steel ◽  
Micro Hardness ◽  
Untreated Sample ◽  
Nitriding Time ◽  
Optimal Duration ◽  
Salt Bath Nitriding

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.

Influence of QPQ Treatment on the Corrosion Behavior for Carbon Steel

2012 ◽  
Vol 155-156 ◽  
pp. 922-925
Author(s):  
Fei Sun ◽  
Wei Cai ◽  
Fan Na Meng ◽  
Jing Hu
Keyword(s):  
Corrosion Resistance ◽  
Complex Salt ◽  
Salt Bath ◽  
Hot Water ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
Cross Sectional ◽  
Process Characterization ◽  
Modified Surface

45 steel was selected as the testing material, QPQ salt bath treatment was conducted by nitriding at the same teperature of 565°C for various time, followed by the same post-oxidation process. Characterization of modified surface layers was made by optical microscopy, X-ray diffraction and corrosion test. The results showed that the cross sectional microstructure was consisted of a thin oxide layer of Fe3O4 at the external surface formed during post-oxidation, a bright zone of εnitrides at the subsurface formed during nitriding and a diffusion zone related to the core. The corrosion resistance of 45 steel in hot water can be significantly improved by QPQ complex salt bath treatment, and the suitable duration of nitriding and post-oxidation to improve the corrosion resistance was 90min and 100min, respectively.

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
Keyword(s):  
Wear Resistance ◽  
Surface Hardness ◽  
Compound Layer ◽  
Salt Bath ◽  
Optical Microscope ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
H13 Steel ◽  
Nitriding Time ◽  
Hardness Tester

<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>

scholarly journals Fabrication and Mechanical Characterization of Stir Cast AA6063-Borosilicate-Fly Ash Hybrid Metal Matrix Composites

2018 ◽  
Vol 7 (3.6) ◽  
pp. 101 ◽  
Author(s):  
G Jims John Wessley ◽  
A Gaith Franklin ◽  
S J. Vijay
Keyword(s):  
Wear Resistance ◽  
Fly Ash ◽  
Aluminium Alloy ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Wear Test ◽  
Hardness Test ◽  
Structural Applications

This paper presents the development and characterization of aluminium alloy 6063 based metal matrix composite with varying combinations of fly ash and Borosilicate reinforcements.  In the present work, the aluminium alloy 6063 (AA) is taken at a constant 84 vol% while the reinforcements Fly Ash (FA) and Borosilicate (B) are varied in the proportions of 2%, 4% 8%, 125 and 14%. Six samples were fabricated by stir casting and the mechanical properties were analyzed using tensile test, hardness test and wear test while the microstructure is analyzed by obtaining SEM and EDX images of the specimen. It is seen that both the reinforcements used in this study, increased the tensile and wear resistance of the alloy. The desirable mechanical and micro structural properties were found to be in the specimen with 84% AA, 14% FA and 2% B. The tensile strength of the aluminum alloy at this desirable combination is found to increase by 11.97%, ductility by 36.75% and the wear resistance by 62%.  This metal matrix composite of AA6063 with fly ash and Borosilicate reinforcements can be used in automobile, aerospace and structural applications where wear resistance and tensile properties are mainly required.

Influence of Rare Earth on the Properties of H13 Steel by the QPQ Salt-Bath Treatment

2010 ◽  
Vol 97-101 ◽  
pp. 1454-1458 ◽  
Author(s):  
Guang Yao Xiong ◽  
Ming Juan Zhao ◽  
Long Zhi Zhao ◽  
Zhang Jian
Keyword(s):  
Wear Resistance ◽  
Rare Earth ◽  
Sliding Wear ◽  
Salt Bath ◽  
Structure And Properties ◽  
Micro Hardness ◽  
H13 Steel ◽  
Hardness Tester ◽  
Different Content

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.

KINETICS ANALYSIS OF HIGHER TEMPERATURE SALT BATH NITRIDING FOR AISI 1045 STEEL

2016 ◽  
Vol 23 (06) ◽  
pp. 1650049 ◽  
Author(s):  
MINGYANG DAI ◽  
YAO CHEN ◽  
YATING CHAI ◽  
JING HU
Keyword(s):  
Compound Layer ◽  
Salt Bath ◽  
Micro Hardness ◽  
Kinetics Analysis ◽  
Cross Sectional ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
Higher Temperature ◽  
1045 Steel ◽  
Salt Bath Nitriding

Rapid salt bath nitriding was conducted at higher temperature above 600[Formula: see text]C instead of normally used 560[Formula: see text]C for AISI 1045 steel. Optical microscopy (OM), X-ray diffraction (XRD) and micro-hardness tester were employed to characterize the microstructure, phase constituents and micro-hardness of the treated specimens. The results showed that salt bath nitriding at higher temperature could significantly increase the compound layer thickness and higher cross-sectional hardness can be obtained. Kinetics analysis illustrated that the nitrogen atoms diffusion coefficient was obviously increased with temperature, and the activation energy of nitrogen atom diffusion was decreased from 220[Formula: see text]kJ[Formula: see text]mol[Formula: see text] to 142[Formula: see text]kJ[Formula: see text]mol[Formula: see text].

QPQ Salt Bath Nitriding and Corrosion Resistance

2006 ◽  
Vol 118 ◽  
pp. 131-136 ◽  
Author(s):  
Yuan Hui Li ◽  
De Fu Luo ◽  
Shao Xu Wu
Keyword(s):  
Corrosion Resistance ◽  
Water Solution ◽  
Salt Spray ◽  
Complex Salt ◽  
Compound Layer ◽  
Salt Bath ◽  
Nitriding Temperature ◽  
Surface Strengthening ◽  
Higher Temperature ◽  
Salt Bath Nitriding

The QPQ complex salt bath treatment is a type of surface strengthening technology which contains mainly salt bath nitriding and salt bath post-oxidizing processes. The effect of nitriding temperature and duration on the corrosion resistance of QPQ treated specimens is explored by immersion tests and salt spray tests in this paper. The material used in this study was 1020 annealed steel. In the immersion tests, the specimens were immersed in 3‰H2O2 and 10% NaCl water solution. In the salt spray tests, specimens were salt spray tested using a 5% NaCl neutral solution. The data indicate that, when the nitriding duration is less than 2 hours at temperature below 590(phase change will exist when the nitriding temperature is above 590 according to Fe-N phase diagram) , the higher temperature of the salt bath nitriding , the specimens will have the higher corrosion resistance. In addition we have found that nitriding for too short a time generates a thin compound layer, and nitriding for too long generates too much porosity. Both will deteriorate the corrosion resistance.

Research of Microstructure and Properties of the 4Cr14Ni14W2Mo Steel with QPQ Salt-Bath Nitriding

2008 ◽  
Vol 373-374 ◽  
pp. 260-263 ◽  
Author(s):  
Guang Yao Xiong ◽  
Bo Lin He ◽  
Rui Zou
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Low Temperature ◽  
White Layer ◽  
Surface Hardness ◽  
Complex Salt ◽  
Salt Bath ◽  
Experimental Results ◽  
Process Time ◽  
High Production Rate

The wear-resistance, corrosion resistance, hardness can be greatly increased by using low temperature QPQ complex salt-bath treatment. And it is a new strengthening method without distortion in the treating process. The surface of 4Cr14Ni14W2Mo 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 corrosion resistance was tested in the 5%NaCl water by using spraying method. The experimental results indicate that a certain depth of white layer and diffusion layer of the steel can be obtained by using low temperature QPQ complex salt-bath treatment. The nitriding compound layer with high hardness, superior wear resistance and stable microstructure, can also be obtained on the surface of the parts. The highest hardness in the surface is HV0.11012. The surface hardness is 2.8 times higher than that of inner part. The depth of white layer is from 10 to 12μm. The experimental results and applied results show that the low temperature QPQ complex salt-bath treatment has many advantages, such as fast nitriding speed, uniform heating, short process time, low treating temperature, small distortion, high production rate, low cost, stable nitriding quality no pollution and so on.

Effects of Y2O3 on the microstructure and wear resistance of WC/Ni composite coatings fabricated by plasma transferred arc

2020 ◽  
Vol 10 (5) ◽  
pp. 634-639
Author(s):  
Yue Hou ◽  
Haiyan Chen ◽  
Qian Cheng ◽  
Li Fan ◽  
Lihua Dong
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Hardness Test ◽  
Micro Hardness ◽  
Plasma Transferred Arc ◽  
Transferred Arc ◽  
Microscopic Morphology

The present study envisaged the WC-reinforced nickel composite coatings prepared on the surface of 4145H steel using the plasma transferred arc (PTA) method. The effects of different content of Y2O3 on the microscopic morphology, phase composition, micro-hardness and wear behavior were investigated by scanning electron microscopy (SEM) with an energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), micro-hardness test and wear experiments. The deposited coatings consisted of WC-reinforced Ni59 composite coatings with the addition of 0 wt%, 0.5 wt% and 1 wt% Y2O3. Microstructural observation showed that the addition of 0.5 wt% Y2O3 had a better improvement on the coarse dendrites and the grain refinement. The main phase composition of the composite coatings was γ-Ni, FeNi3 solid solution, γ(Fe, Ni) eutectic phase, and the hard phase of WC, W2C. The cladding layer added with 0.5 wt% Y2 O3 was preferable over the Y2O3-free coating, as the microhardness was improved from 500 HV to 800 HV with a slight fluctuation of values. The coating with 0.5 wt% Y2O3 offered an excellent wear resistance to the extrusion and cracks for the uniformity of organizational structure compared with the substrate and the other two coatings. Furthermore, the results of weightlessness and coefficient of friction proved the positive effect of the rare earth Y2O3 on the wear resistance.

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