scholarly journals Influence of Particle Reinforcement and Heat Treatment on the Wear Resistance of Inductively Melted Hardpaint Coatings

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 968
Author(s):  
Patrick Schwarz ◽  
Sebastian Weber ◽  
Friederike Deuerler

Wear-resistant coatings can reduce the high economic damage caused by wear processes. In this study, various protective layers based on the alloy X400CrVMo17-15-2 were investigated. Commonly, the prealloyed metal powder is used for plasma transferred arc powder surfacing. However, in this work, the cost-efficient hardpaint technology was used to produce particle-reinforced (fused tungsten carbides) and non-reinforced coatings. To analyze the wear behavior, the coatings were subjected to abrasion wear and scratch tests. For the abrasion wear test, a grinding pin (Al2O3) is pressed with a defined force against the surface of the rotating sample for 6 h. For the scratch test, a loaded diamond pyramid indenter was employed to create a circular groove on the coatings at a predefined speed. The wear grooves were analyzed with the aid of laser scanning microscopy. In comparison to the coatings in the as-processed condition, the non-reinforced protective layers were investigated after quenching, with and without deep cryogenic treatment, and tempering. The determination of proper heat treatment parameters was supported by computational thermodynamics. It has been confirmed that it is possible to improve the wear resistance of the unreinforced coatings by heat treatment. However, the reinforced layers showed the highest resistance against abrasion.

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Mengjiao Wang ◽  
Yunxia Wang ◽  
Jianzhang Wang ◽  
Na Fan ◽  
Fengyuan Yan

Super duplex stainless steel (SDSS) has excellent mechanical properties and corrosion resistance. However, currently, there are few researches conducted on its fretting wear performance. This paper studies the influence of different heat treatment temperatures and medium environment on the fretting wear performance of SAF 2507 SDSS. Results show that the combined effect of the sigma phase and seawater lubrication can significantly improve the wear resistance of SAF 2507 SDSS. After treated with different heat treatment temperatures, different contents of sigma phases are precipitated out of SAF 2507 SDSS, which improves the wear resistance of the material to different degrees. In addition, the fretting wear performance of SAF 2507 SDSS also relates to the lubrication medium. In air, the friction and wear performance of SAF 2507 SDSS is poor, while in seawater, solution and corrosion products that acted as a lubricant dramatically improve the wear resistance of the material. Under the combined action of heat treatment and seawater lubrication medium, the friction coefficient and wear reduce by 70% and 91%, respectively.


1983 ◽  
Vol 27 ◽  
Author(s):  
K. Kumar ◽  
H. Newborn ◽  
R. Kant

ABSTRACTPin-on-disk tests were performed for comparative friction and wear behavior on flat and graded profile boron implanted beryllium samples. Peak, intended boron concentrations of 10, 20, 30 and 40 atom percent were investigated. Auger Electron Spectroscopy was used to determine the boron concentration as a function of depth. Preliminary work was performed to study the effects of (1) a low temperature (450°C, 1–1/2 hours) heat treatment of the implanted specimens and (2) a change in the pin material. All of the boron implanted beryllium samples showed significant improvement versus unimplanted beryllium and an anodized beryllium surface. Graded samples showed comparable friction coefficients but inferior wear resistance with respect to the flat profile samples.


2019 ◽  
Vol 141 (4) ◽  
Author(s):  
P. Karuppusamy ◽  
K. Lingadurai ◽  
V. Sivananth

The present investigation explores the collective outcome of hard particle reinforcement with deep cryogenic treatment (DCT) on wear responses of magnesium metal matrix nanocomposites (MMNC). A multilevel factorial design of experiments with control factors of applied load (20 and 40 N), sliding speed (1.3, 1.7, 2.2, and 3.3 m/s), reinforcement % (0% and 1.5%), and cryogenic treatment (cryogenic-treated and nontreated) was deployed. Around 1.5 wt % WC-reinforced MMNC were fabricated using stir-casting process. DCT was performed at −190 °C with soaking time of 24 h. The dry sliding wear trials were done on pin-on-disk tribometer with MMNC pin and EN8 steel disk for a constant sliding distance of 2 km. The WC reinforcement contributed toward the improvement in wear rate of MMNC appreciably by absorbing the load and frictional heat at all loads and speeds. During DCT of AZ91, the secondary ß-phase (Mg17Al12) was precipitated that enriched the wear resistance, only for the higher load of 40 N. Scanning electron microscope analyses of the cryogenic-treated MMNC ensured the existence of both ß-phase precipitates and WC in the contact area. As a result, the adhesiveness of this pin was lesser, which attributed to the improved wear resistance (approximately 33%) as compared to base alloy. The coefficient of friction was also less for cryogenic-treated MMNC. A regression analysis was made to correlate the control elements and the responses.


Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1038 ◽  
Author(s):  
Pello Jimbert ◽  
Maider Iturrondobeitia ◽  
Julen Ibarretxe ◽  
Roberto Fernandez-Martinez

The effects of deep cryogenic treatment (DCT) on the wear behavior of different tool steels have been widely reported in the scientific literature with uneven results. Some tool steels show a significant improvement in their wear resistance when they have been cryogenically treated while others exhibit no relevant amelioration or even a reduction in their wear resistance. In this study, the influence of DCT was investigated for a grade that has been barely studied in the scientific literature, the AISI A8 air-hardening medium-alloy cold work tool steel. Several aspects were analyzed in the present work: the wear resistance of the alloy, the internal residual stress, and finally the secondary carbide precipitation in terms of lengths and occupied area and its distribution into the microstructure. The results revealed a reduction in the wear rate of about 14% when the AISI A8 was cryogenically treated before tempering. The number of carbides that precipitated into the microstructure was 6% higher for the cryogenically treated samples, increasing from 0.68% to 0.73% of the total area they covered. Furthermore, the distribution of the carbides into the microstructure was more homogenous for the cryogenically treated samples.


Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2011 ◽  
Author(s):  
Wenhu Li ◽  
Taotao Ai ◽  
Hongfeng Dong ◽  
Guojun Zhang

According to the stoichiometric ratios of Mo-10Si-7B, Mo-12Si-8.5B, Mo-14Si-9.8B, and Mo-25Si-8.5B, some new Mo-Si-B alloys doped with 0.3 wt % lanthanum (III) oxide (La2O3) were prepared via liquid-liquid (L-L) doping, mechanical alloying (MA), and hot-pressing (HP) sintering technology. The phase-composition and microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The worn surfaces of the plate specimens were studied by confocal laser scanning microscopy (CLSM). Then, the tribological properties of Mo-Si-B alloy doped with sliding plate specimens of 0.3 wt % La2O3 were investigated against the Si3N4 ball specimens. The friction coefficients of Mo-Si-B alloys decreased and the wear rates of the alloys increased with test load. The high-temperature friction and wear behavior of Mo-Si-B alloy are related to the surface-oxidation and contact-deformation of the alloy at a high temperature. The low friction coefficients and the reduced wear rates are thought to be due to the formation of low friction MoO3 films. MoO3 changed the contact state of the friction pairs and behaved as lubricating films.


Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1321 ◽  
Author(s):  
Arnoldo Bedolla-Jacuinde ◽  
Francisco Guerra ◽  
Ignacio Mejia ◽  
Uzzi Vera

From the present study, niobium additions of 1.79% and 3.98% were added to a 15% Cr–3% C white iron, and their effects on the microstructure, hardness and abrasive wear were analyzed. The experimental irons were melted in an open induction furnace and cast into sand molds to obtain bars of 45 mm diameter. The alloys were characterized by optical and electron microscopy, and X-ray diffraction. Bulk hardness was measured in the as-cast conditions and after a destabilization heat treatment at 900 °C for 30 min. Abrasive wear resistance tests were undertaken for the different irons according to the ASTM G65 standard in both as-cast and heat-treated conditions under three loads (58, 75 and 93 N). The results show that niobium additions caused a decrease in the carbon content in the alloy and that some carbon is also consumed by forming niobium carbides at the beginning of the solidification process; thus decreasing the eutectic M7C3 carbide volume fraction (CVF) from 30% for the base iron to 24% for the iron with 3.98% Nb. However, the overall carbide content was constant at 30%; bulk hardness changed from 48 to 55 hardness Rockwell C (HRC) and the wear resistance was found to have an interesting behavior. At the lowest load, wear resistance for the base iron was 50% lower than that for the 3.98% Nb iron, which is attributed to the presence of hard NbC. However, at the highest load, the wear behavior was quite similar for all the irons, and it was attributed to a severe carbide cracking phenomenon, particularly in the as-cast alloys. After the destabilization heat treatment, the wear resistance was higher for the 3.98% Nb iron at any load; however, at the highest load, not much difference in wear resistance was observed. Such a behavior is discussed in terms of the carbide volume fraction (CVF), the amount of niobium carbides, the amount of martensite/austenite in matrix and the amount of secondary carbides precipitated during the destabilization heat treatment.


2021 ◽  
Author(s):  
Ville Akujärvi ◽  
Tord Cedell ◽  
Oleksandr Gutnichenko ◽  
Matias Jaskari ◽  
Mats Andersson

Abstract Quality control in heat treatment of steel is often conducted after the treatment. Failure to confine within the specified range of mechanical properties may lead to wasted energy and production resources. Performing quality control in-line in the heat treatment process allows for early detection and possibility to react to changes in the process. The prospects of utilizing the change in the electromagnetic (EM) properties of steel, as means for quality control, is investigated in this paper. The focus is on the tempering process of hardened SS2244 (42CrMoS4) steel. The tempering takes the hardness of the steel from approximately 600 HV down to around 400 HV. The EM signature of the steel is recorded during the tempering process. This is later compared to results from more traditional means of material characterization, such as Laser Scanning Microscopy, X-ray Diffractometry and Vickers microhardness measurement. This initial study shows clear indications of precise detection of the hardness through EM properties during tempering process of selected material.


Author(s):  
Sanjeev Katoch ◽  
Rakesh Sehgal ◽  
Vishal Singh

The effect of different cryogenic treatments on the wear behavior of chromium base die steel under dry condition has been examined at five levels of sliding velocity and normal loads. Parameters chosen for cryogenic treatment cycles are subjected to soaking duration of 6, 21, and 36 h at soaking temperatures of −154 ℃ and −184 ℃. Soaking period of 21 h shows higher wear resistance, whereas 36 h treatment shows the reduction in wear resistance. Worn out surface and wear debris exhibit that mechanisms responsible for wear of samples are rupturing of martensitic matrix and delaminating.


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