• Title/Summary/Keyword: wear behavior

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Effects of Counterpart Materials on Wear Behavior of Thermally Sprayed Ni-based Self-flux Alloy Coatings (니켈기 자융성 합금 코팅층의 마모거동에 미치는 상대마모재의 영향)

  • Kim, K.T.;Kim, Y.S.
    • Journal of Power System Engineering
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    • v.11 no.4
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    • pp.92-97
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    • 2007
  • This study aims at investigating the wear behavior of thermally sprayed Ni-based self-flux alloy coatings against different counterparts. Ni-based self-flux alloy powders were flame-sprayed onto a carbon steel substrate and then heat-treated at temperature of $1000^{\circ}C$. Dry sliding wear tests were performed using the sliding speeds of 0.2 and 0.8 m/s and the applied loads of 5 and 20 N. AISI 52100, $Al_2O_3$, $Si_3N_4$ and $ZrO_2$ balls were used as counterpart materials. Wear behavior of Ni-based self-flux alloy coatings against different counterparts were studied using a scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy (EDX). It was revealed that wear behavior of Ni-based self-flux alloy coatings were much influenced by counterpart materials.

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Analysis of Sliding Wear Behavior of Mild Steel According to Hardness of Dissimilar Mating Materials (이종 상대재 경도에 따른 철강재료의 미끄럼 마모 특성 해석)

  • Lee, Han-Young
    • Tribology and Lubricants
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    • v.32 no.6
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    • pp.195-200
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    • 2016
  • This study examines the wear behavior of mild steel pins mated against alloyed tool steel discs in a pin-on-disc type sliding test machine and provides specific clarification regarding the effects of disc hardness on the wear behavior of a mating mild steel pin. The analysis confirms these effects through the observation of differences in the wear rates of the mild steel pins at low sliding speed ranges. These differences occur even though the hardness of the mating disc does not affect the wear characteristic curve patterns for the sliding speeds, regardless of the wear regime. In the running-in wear regime, increasing the hardness of the mating disc results in a decrease in the wear rates of the mild steel pins at low sliding speed ranges. However, in the steady-state wear region, the wear rate of a pin mated against the 42DISC is greater than the wear rate of a pin mated against the 30DISC, which has a lower hardness value. This means that the tribochemical reactivity of the mating disc, which is based on hardness value, influences the wear behavior of mild steel at low sliding speed ranges. In particular, oxides with higher oxygen contents, such as $Fe_2O_3$ oxides, form predominantly on the worn surface of the 42DISC. On the contrary, the wear behavior of mild steel pins at high sliding speed ranges is nearly unaffected by the hardness of the mating disc.

Effects of Corrosion Resistance Characteristics of Opponent Materials in relative Motion on Sliding Wear Behavior of Mild Carbon Steel (상대재 내식성이 철강재료의 미끄럼마모 특성에 미치는 영향)

  • Lee, Han-Young
    • Tribology and Lubricants
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    • v.35 no.2
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    • pp.139-147
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    • 2019
  • This study investigates the effects of corrosion resistance characteristics of opponent materials in relative motion on the sliding wear behavior of mild carbon steel. Pin specimens made of mild carbon steel are tested at several sliding speeds against mating discs made of two types of alloyed steels, such as type D2 tool steel (STD11) and type 420 stainless steel (STS420J2), with different corrosion resistance characteristics in a pin-on-disc type sliding wear test machine. The results clearly show that the sliding wear behavior of mild carbon steel is influenced by the corrosion resistance characteristics of the mating disc materials at low sliding speeds. However, the sliding wear behavior at high sliding speeds is irrelevant to the characteristics because of the rising temperature. During the steady state wear period, the sliding wear rate of mild carbon steel against the type 420 stainless steel at a sliding speed of 0.5 m/s increases considerably unlike against the type D2 tool steel. This may be because the better corrosion resistance characteristics achieve a worse tribochemical reactivity. However, during the running-in wear period at low sliding speeds, the wear behavior of mild carbon steel is influenced by the microstructure after heat treatment of the mating disc materials rather than by their corrosion resistance characteristics.

Wear Behavior of Al/SiC Composites Fabricated by Thermal Spray Process (1) - Effect of Sliding Speed on Wear Behavior - (용사법에 의해 제조된 Al/SiC 복합재료의 마모거동 (1) - 미끄럼 속도의 영향 -)

  • Lee, Kwang-Jin;Kim, Kyun-Tak;Kim, Yeong-Sik
    • Tribology and Lubricants
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    • v.27 no.6
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    • pp.351-355
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    • 2011
  • Al/SiC composites were fabricated by thermal spray process, and the dry sliding wear tests were performed using the various sliding speed of 10, 30, 60 and 90 RPM through 1000 cycles. The applied load was 10 N and radius of wear track was 15 mm. Wear tracks on the Al/SiC composites were investigated using scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy (EDS). In the case of sliding speed of 10 RPM, adhesive wear behavior caused by plastic deformation of composits surface was observed. In the cases of sliding speed of 30, 60, 90 RPM, abrasive wear behavior on the adhered layer formed by debris were observed. Through this study, it was found that the wear behavior of Al/SiC composites was mainly influenced by the sliding speed.

Effects of Counterpart Materials on Wear Behavior of Thermally Sprayed STS316 Coatings (STS316 용사코팅층의 마모거동에 미치는 상대마모재의 영향)

  • Lee, Jae-Hong;Kim, Yeong-Sik
    • Journal of Power System Engineering
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    • v.18 no.6
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    • pp.58-63
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    • 2014
  • This paper deals with the effects of counterpart materials on the wear behavior of thermally sprayed STS316 coatings. STS316 powders were flame-sprayed onto a carbon steel substrate. Dry sliding wear tests were performed using the applied loads of 15 N. AISI52100, $Al_2O_3$, $ZrO_2$ and $Si_3N_4$ balls were used as counterpart materials. Wear behavior of STS316 coatings against different counterpart materials were studied using a scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy (EDS). The results show that the wear behavior of thermally sprayed STS316 coatings strongly depends on the type of counterpart material. Dominant wear mechanism was similar for all studied materials as failure of adhesion film except for Si3N4 used as counterpart material. In the case of Si3N4 used as counterpart material, dominant wear mechanism was abrasion.

A Study on the Rail Materials Technology for Subway Based on its Sliding Wear Behavior (지하철 레일의 미끄럼 마모거동을 고려한 재료설계에 대한 고찰)

  • Lee, Han-Young
    • Tribology and Lubricants
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    • v.30 no.6
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    • pp.364-369
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    • 2014
  • To assess the wear behavior of rails against subway rail car wheels, we investigate the sliding wear behavior of pins derived from two types of rails (normal rails and heat-treated rails) against a disc derived from a subway rail car wheel, using a pin-on-disc-type tribometer. We base the sliding wear test conditions on the sliding conditions for wheel flange-rail gauge corner contact. We demonstrate the remarkable transition in the wear behavior of the pins derived from the rails, from severe wear to mild wear, as a function of the sliding distance. The wear rate of the heat-treated rail material in the running-in wear region is much lower than that of the normal rail material. Furthermore, the wear rates of the pins in the running-in wear region decrease with increasing hardness and with decreasing sliding speed. However, there is little difference between the heat-treated rail pin and the normal rail pin in the wear rate in the steady-state wear region. Stricter controls on the decarburized layer beneath the surface of rails are required to reduce the wear rate in the running-in wear region.

Review on the Wear behavior of the Hot Stamping Process with Respect to Friction Testing Methods (마찰 방법에 따른 핫스탬핑 마모 거동의 연구 동향)

  • Ji, Min-Ki;Jun, Tea-Sung
    • Tribology and Lubricants
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    • v.36 no.6
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    • pp.350-358
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    • 2020
  • Hot stamping is an effective and suitable process widely used in automotive applications, though critical issues such as the transfer of the coating materials and build-up of these materials on tool surfaces have been encountered. Past researches figured out the resultant wear phenomenon using pin-on-disc and drawing (for example, strip drawing and deep drawing) methods to mimic the process and analyzed the wear behavior with respect to the influencing factors such as surface coating, load, and roughness. Although the pin-on-disc is a conventional and widely-used method, it presented a methodological limitation when simulating the hot stamping process by forming a new blank each time, and hence, a drawing-based friction method has been proposed and developed. Each drawing method applies loads in a different way, resulting in a different wear behavior. Notably, the deep drawing process is most similar to the hot stamping process compared to other drawing methods. In this paper we present a review of the friction testing methods mimicking the hot stamping process and the associated wear behavior. This can be helpful in presenting a step-by-step approach and different perspectives on the wear behavior in the hot stamping process.

Effect of Heat Treatment Conditions on the Microstructure and Wear Behavior of Ni-based Self-flux Alloy Coatings (니켈기 자융성 합금 코팅층의 미세구조 및 마모거동에 미치는 후열처리 조건의 영향)

  • Kim, K.T.;Oh, M.S.;Kim, Y.S.
    • Journal of Power System Engineering
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    • v.11 no.1
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    • pp.121-126
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    • 2007
  • This study aims at investigating the effect of heat treatment conditions on the dry sliding wear behavior of thermally sprayed Ni-based self-flux alloy coatings. Ni-based self-flux alloy powders were sprayed onto a carbon steel substrate and then heat-treated at 700, 800, 900 and $1000^{\circ}C$ for 30 minutes in a vacuum furnace. Dry sliding wear tests were performed using sliding speed of 0.4 m/s and applied load of 6 N. AISI 52100 ball(diameter 8 mm) was used as counterparts. Microstructure and wear behavior of both as-sprayed and heat-treated Ni-based self-flux alloy coatings were studied using a scanning electron microscope(SEM), energy dispersive X-ray spectroscopy(EDX), electron probe micro-analysis(EPMA) and X-ray diffraction(XRD). It was revealed that microstructure and wear behavior of thermally sprayed Ni-based self-flux alloy coatings were much influenced by heat treatment conditions.

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Effects of Process Parameters on the Wear Behavior of Thermally Sprayed Ni-based Hard Coatings (니켈기 경질 용사코팅의 마모거동에 미치는 공정조건의 영향)

  • Kim, Kyun-Tak;Kim, Yeong-Sik
    • Tribology and Lubricants
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    • v.26 no.3
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    • pp.157-161
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    • 2010
  • This study investigated the effects of spray parameters on wear behavior of the Ni-based hard coatings fabricated by thermal spray process. The experiment was designed by an orthogonal array, the Ni-based hard coatings were fabricated according to this experimental design. The wear test was performed on these coatings using ball-on-disk wear tester. The ANOVA was used to analyze the effects of spray parameters on the wear rate of these coatings, as a result, oxygen gas flow and acetylene gas flow were determined as main factors effected on the wear rate. The effects of these two factors on wear behavior were observed by using SEM and EDX.

Effects of Combination of the Load and the Apparent Area of Contact on Sliding Wear behavior of Mild Steel in a Pin-on-disc Type Apparatus (Pin-on-Disc식 미끄럼마모시험 시 마모 거동에 미치는 접촉면적 및 하중 조합의 영향)

  • Lee, Han-Young
    • Tribology and Lubricants
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    • v.29 no.2
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    • pp.85-90
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    • 2013
  • The effects of contact pressure on the sliding wear behavior of mild steel in a pin-on-disc type apparatus were investigated. Sliding wear tests were conducted with various combinations of the load and apparent area of contact. The wear behavior of mild steel as a function of sliding speed was independent of contact pressure. However, the wear rate at different sliding speeds was influenced by the load regardless of the apparent area of contact. This was attributed to the fact that there may be no difference in the real area of contact for any combination of the load and apparent area of contact.