The Experts below are selected from a list of 3249 Experts worldwide ranked by ideXlab platform
S Chatterjee - One of the best experts on this subject based on the ideXlab platform.
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wear behaviour of hardfacing deposits on cast iron
Wear, 2003Co-Authors: S ChatterjeeAbstract:The abrasive wear behaviour of different hardfacing electrodes deposited on grey cast iron used for the top bearing plate of a coal crushing unit was studied using the dry sand rubber wheel Abrasion test. The results show that different hardfacing electrodes as well as the weld procedure variation using similar electrodes have large effects on low Stress Abrasion resistance of the deposit. Such effects on the Abrasion resistance are mainly attributed to the variation in deposit chemistry and microstructures. Carbon content is an important factor determining microstructure of such hardfacing electrodes and therefore wear resistance. Furthermore, the wear behaviour also indicated that the abrasive wear resistance is not simply related to the hardness of the deposit but is determined by the carbides and matrix structure of the deposits.
B Venkataraman - One of the best experts on this subject based on the ideXlab platform.
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abrasive wear behaviour of wc cocr and cr3c2 20 nicr deposited by hvof and detonation spray processes
Surface & Coatings Technology, 2006Co-Authors: J K N Murthy, B VenkataramanAbstract:Abstract Thermally sprayed tungsten carbide-based and chromium carbide-based coatings are being widely used for a variety of wear resistance applications. These coatings deposited by high velocity processes like high velocity oxy-fuel (HVOF) and detonation gun spray (DS) techniques are known to provide improved wear performance. In the present study, WC–10Co–4Cr and Cr3C2–20(NiCr) coatings are deposited by HVOF and pulsed DS processes, and low Stress Abrasion wear resistance of these coatings are compared. The Abrasion tests were done using a three-body solid particle rubber wheel test rig using silica grits as the abrasive medium. The results show that the DS coating performs slightly better than the HVOF coating possibly due to the higher residual compressive Stresses induced by the former process and WC-based coating has higher wear resistance in comparison to Cr3C2-based coating. Also, the thermally sprayed carbide-based coatings have excellent wear resistance with respect to the hard chrome coatings.
B K Prasad - One of the best experts on this subject based on the ideXlab platform.
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factors controlling the abrasive wear response of a zinc based alloy silicon carbide particle composite
Composites Part A-applied Science and Manufacturing, 1997Co-Authors: B K Prasad, S Das, A K Jha, O P Modi, R Dasgupta, A H YegneswaranAbstract:Abstract Attention has been focused in this study on the (two-body/high-Stress) Abrasion characteristics of a zinc-based alloy reinforced with hard SiC second phase articles (SPPs) under the influence of varying load, sliding distance and abrasive size. The unreinforced matrix alloy processed similarly was also subjected to identical test conditions. It was observed that the wear response of the specimens is influenced markedly by the applied load, sliding distance and the size of the abrasive particles. Different operative wear mechanisms were found to be responsible for the changing behaviour of the samples. Reinforcement with hard SPPs (SiC) in the zinc-based alloy matrix was beneficial when tests were conducted with fine abrasive particles over the entire range of applied loads and sliding distance. On the contrary, however, this trend reversed when coarser abrasive particles were used. Further, the wear rate reduced with sliding distance, while load affected the wear behaviour of the specimens in the opposite manner. These effects, of course, were more prominent under severe conditions of Abrasion (i.e. higher load or coarser abrasive). The wear characteristics of the samples have been explained on the basis of factors such as degradation of the abrasive, as well as reinforcing SPP and Abrasion-induced work hardening of the subsurface regions. In addition, the predominance of one or more processes such as capping, clogging, shelling and attrition, leading to a deteriorating cutting efficiency of the abrasive and brittle fragmentation of the SPPs, affected the wear response of the specimens markedly under a given set of experimental conditions.
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mechanisms of material removal and subsurface work hardening during low Stress Abrasion of a squeeze cast aluminium alloy al2o3 fibre composite
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 1992Co-Authors: B K Prasad, S V PrasadAbstract:Abstract Low-Stress abrasive wear behaviour of squeeze-cast aluminium alloy (British Standard LM5) and its composite containing 10 vol.% of Al 2 O 3 fibres has been examined in this study using an ASTM standard rubber wheel Abrasion test apparatus. Silica sand particles (size, 212–300 μm) were used as the abrasive. A progressive decrease in wear rate with increasing number of test intervals, until a steady state value was reached, was noticed for the base alloy as well as the composite. Abrasion-induced subsurface work hardening was found to be responsible for the progressive reduction in the wear rate of the base alloy. Factors causing identical behaviour of the composite were noted to be the protusion of the reinforcement, i.e. Al 2 O 3 fibres on the abraded surface offering protection to the softer matrix, as well as the Abrasion-induced subsurface matrix hardening. Scanning electron microscope examination of the abraded and transverse sections suggested the material removal mechanism of the composite to consist of preferential removal of the matrix in the beginning, leading to the protrusion of the dispersoid phase (the latter offered protection to the matrix) and finally the subsequent fracture and partial removal of the dispersoid from the surface.
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Abrasion induced microstructural changes during low Stress Abrasion of a plain carbon 0 5 c steel
Wear, 1991Co-Authors: B K Prasad, Somuri V PrasadAbstract:Abstract A plain carbon (0.5% C) steel was subjected to various heat treatment cycles to produce a variety of microstructures. Low Stress Abrasion tests were conducted using an ASTM standard rubber wheel Abrasion test apparatus. Crushed silica sand particles were used as the abrasive medium. The wear loss decreased progressively with the number of test intervals until a steady state was reached. The steady state Abrasion resistance was found to increase linearly with bulk hardness up to about 350 HV beyond which there was a marginal increase. Abrasion-induced changes were studied via metallographic examinations of transverse sections and hardness vs . depth (below the abraded surface) profiles. Abraded surfaces and wear debris were examined in a scanning electron microscope equipped with a wavelength-dispersive X-ray spectroscope. The hardened steel showed a large number of continuous and parallel grooves, while the annealed specimen revealed a considerable amount of micropitting in addition to the grooves. Wear debris from the annealed specimen was mainly of the flake type, while long micromachining chips of the “card-deck” type were observed in the case of the hardened steel. The results of this study revealed that the material removal mechanisms during Abrasion of steels are controlled by the properties of a layer beneath the abraded surface. The properties of this layer are in turn governed by the bulk microstructure.
Kati Valtonen - One of the best experts on this subject based on the ideXlab platform.
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high Stress Abrasion of wear resistant steels in the cutting edges of loader buckets
Tribology International, 2018Co-Authors: Kati Valtonen, Kimmo Keltamaki, Velitapani KuokkalaAbstract:Abstract To simulate the wear behavior of the cutting edge of the mining load-haul-dumper bucket, high-Stress Abrasion laboratory wear tests were conducted and compared to the in-service tests. The effects of test parameters and different abrasives on the wear rates and wear mechanisms of wear resistant steels were studied using the high-speed slurry-pot with a dry abrasive bed (dry-pot) and in the actual in-service use as a cutting edge. The laboratory wear tests produced results that are well comparable with the in-service case observations. Especially at the higher sample rotation speed with granite as an abrasive, the wear rates were quite similar as determined from the cutting edge of a loader bucket that had been used in a mine.
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the role of microstructure in high Stress Abrasion of white cast irons
Wear, 2017Co-Authors: Vuokko Heino, Kati Valtonen, Marke Kallio, V T KuokkalaAbstract:Abstract The Abrasion wear resistance of white cast irons can be controlled primarily by adjusting the size, size distribution, and volume fraction of the carbide phase. The main physical property of white cast irons correlating with Abrasion resistance is hardness. This study concentrates on the evaluation of hardened and Stress relieved, normalized, self-hardened, and as-cast states of high chromium white cast irons in high Stress Abrasion. The correct size and orientation of the carbides were found to be crucial for the wear resistance of white cast irons in high Stress abrasive conditions. The different annealing procedures affected the formation of the carbide structure and its distribution, as well as the microstructure of the matrix. The austenite-to-martensite ratio together with a beneficial carbide structure was found to have a strong effect on the Abrasion wear resistance of WCI specimens.
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wear behavior and work hardening of high strength steels in high Stress Abrasion
Wear, 2015Co-Authors: M Lindroos, Kati Valtonen, Anu Kemppainen, Anssi Laukkanen, Kenneth Holmberg, Velitapani KuokkalaAbstract:Abstract High strength steels (HSS) used in highly abrasive environments, such as in mining and crushing, must endure high Stress Abrasion. To properly understand the wear behavior of materials under such circumstances, the connection between surface loading, work hardening, and material removal has first to be determined. In this study, wear resistant steels with initial hardness ranging from 400 to 750 HV were investigated in single-grit Abrasion. In the cyclic Abrasion experiments, the Abrasion resistance of the steels was improved noticeably from the initial state due to surface hardening. However, the highest surface hardening rate did not result in the highest wear resistance. Moreover, when the surface loading was sufficiently increased, the transition to a high wear rate mechanism was observed.
Lutz Michael Berger - One of the best experts on this subject based on the ideXlab platform.
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influence of heat treatment on the abrasive wear resistance of a cr3c2nicr coating deposited by an ethene fuelled hvof spray process
Surface & Coatings Technology, 2016Co-Authors: Leo Janka, Jonas Norpoth, Richard Trache, Lutz Michael BergerAbstract:Abstract This work reveals the influence of heat treatments on the microstructure, mechanical properties and abrasive wear behaviour of a Cr 3 C 2 NiCr coating deposited by an ethene-fuelled high-velocity oxygen-fuel spray process using an agglomerated-and-sintered feedstock powder. The wear resistance of an as-sprayed and heat treated (8 h at 800 °C) coating was evaluated in low- and high-Stress Abrasion regimes, the latter in a temperature range up to 800 °C. Precipitation of secondary carbides from the supersaturated as-sprayed binder matrix is at the core of the observed changes in the coatings wear resistance upon heat treating. This aging process renders the binder matrix softer and more ductile, as was probed by means of nanoindentation, and thereby improves its resistance against micro-cracking which is identified as an important wear mechanism in high-Stress Abrasion conditions.
