• 제목, 요약, 키워드: Wear

검색결과 6,883건 처리시간 0.042초

박용(舶用) 디이젤기관(機關)의 실린더 라이너 및 피스턴 링의 이상마모(異常摩耗)에 관(關)하여 (On the Abnormal Wear of Cylinder Liners and Piston Rings of the Marine Diesel Engine)

  • 정태준
    • 대한조선학회지
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    • v.8 no.1
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    • pp.95-102
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    • 1971
  • Since the fuel oil of the bunker C grade, which is commonly burnt in the large marine diesel engine, causes the corrosive wear of cylinder liners and piston rings, a cylinder oil of high alkality is frequently used to prevent the wear. This practice, however, brings us an another problem to cause the abnormal wear. In this study the author made an investigation of the mechanism of the abnormal wear by the experiments surveying the influences of the alkality of a cylinder oil and the temperature of cylinder wall on the wear. The major results obtained from this study are as follows; A cylinder oil of low alkality is clearly effective for the preventation of the abnormal wear. Therefore, it is recommended that, prio to using a cylinder oil of high alkality, a cylinder oil of low alkality should be used until bringing an end to the initial wear. It is also observed that the abnormal wear depends largely on the temperature of the cylinder wall, that is, the higher the temperature goes up the severer the wear grows.

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STS 304강의 분위기온도에 따른 부식마멸기구에 관한 연구 (A Study on the Corrosive Wear Mechanism on Atmospherical Temperature of STS 304 Steel)

  • 전태옥;박흥식;주창식
    • 대한기계학회논문집
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    • v.14 no.2
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    • pp.399-406
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    • 1990
  • This paper is studied to know corrosive wear mechanism of STS304 steel on atmospherical temperature against mating material as the same. The corrosive test was carried out by rubbing the annular surface of two test pieces in distilled water and NaCl aqueous solution. The corrosive wear mechanism was investigated by S.E.M. The experimental results show that there is one Lcr transferring from severe wear to mild wear on change of NaCl concentration and atmospherical temperature, and which is the other still remaining in server wear state. It was found that the critical sliding distance Lcr shorten with increasing NaCl concentration but it is longer with ascending atmospherical temperature and the mild wear state still continues under the condition of high generation rate and elimination rate of the corrosive product. Considering upon the result, the model of corrosive wear mechanism is proposed.

오염된 윤활유가 마멸특성에 미치는 영향에 관한 실험적 연구 (An Experimental Study on the Effect of Contaminated Lubricants on Wear Characteristics)

  • 김해원;홍재학
    • 한국정밀공학회지
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    • v.7 no.2
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    • pp.113-123
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    • 1990
  • To study deleterious effects of contaminants contained in lubricating systems, the effects of fine alumina particle concentration and size on the critical failure load, friction and wear characteristic were examined on boundary lubrication condition using the four ball machine. The following conclusions are deduced: The abrasive is found to cause a transition from mild wear to severe wear at less severe conditions than with clean oil. In mild wear region the friction and wear increase with particle size and concentration, but in severe wear region do not exhibit any definite trend. In relation to film thinckness there is a threshold of particle size beyond which the failure load no longer decreases with particle size.

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휠 얼라이먼트 값과 타이어 편마모 영향도 평가 및 분석 (Evaluation and Analysis of Wheel alignment Effecting on Tire Uneven Wear)

  • 정수식;정원욱;이상주;고범진;최영삼
    • 대한기계학회:학술대회논문집
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    • pp.1658-1662
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    • 2007
  • The tire uneven wear has been an ongoing concern for a long time, and one of customer's complaints too. This paper deals with uneven wear improvement of passenger car tires, to have tested the tire wear levels by each wheel alignment set (according to changing toe and camber) using taxis. The pre-set wheel alignments on test vehicle were gained by energy friction simulation of tire. The result of this experiment was as follows : First, verified the effects of initial wheel alignment (adjusted at Curb Vehicle Weight) to minimize tire uneven wear. Second, tire uneven wear makes tire life much shorter than even wear does.

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증기발생기 세관과 지지대 간극이 세관 마모에 미치는 영향 (Effects of Gap between Tube and Support Plate on the Steam Generator Tube Wear)

  • 박치용;이용선;부명환;김태룡;김태순
    • 대한기계학회:학술대회논문집
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    • pp.302-307
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    • 2004
  • The major flow-induced vibration mechanisms such as fluid-elastic and turbulence excitation can cause the various types of wear of the steam generator tubes in unclear power plant. It is generally accepted that the tube wear due to vibration is affected by the presence of gap clearance between tube and support plate. Connors showed that the tube wear depth could be estimated by using the relationship between wear volume and sliding distance for contact time. Au-Yang predicted the wear depth by using the nonlinear characteristics of normal work rate to contact time. In this study the effect of gap size on the steam generator tubes wear is analyzed by deriving the wear depth versus normal work rate relationship from these previous results.

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CFRP 복합재의 적층방향에 대한 마찰 및 마모 특성 (Friction and Wear Characteristics of Carbon Fiber Reinforced Composites against Lay-up Orientation)

  • 고성위;최영근
    • 동력기계공학회지
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    • v.9 no.2
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    • pp.57-64
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    • 2005
  • This paper is the study on dry sliding wear behavior of carbon fiber reinforced epoxy matrix composites against lay-up orientation. Tests were investigated on the effect of the lay-up orientation, fiber sliding direction, load and sliding velocity when circumstance keep continuously at $21^{\circ}C$, 60%RH. Pin-on-disk dry sliding wear tests for each experimental condition were carried out with a carbon fiber reinforced plastic pin on stainless steel disk in order to search the friction and wear characteristics. The wear rates and friction coefficients against the stainless steel counterpart were experimentally determined and the wear mechanisms were microscopically observed. The effect on friction and wear behavior are observed differently, according to various conditions. When sliding took place against counterpart, the highest wear resistance and the lowest friction coefficient were observed in the $[0]_{24s}$ lay-up orientation at anti-parallel direction.

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입자지름의 변화에 따른 실리카 복합재료의 마찰 및 마모 특성 (Friction and Wear Characteristics of Silica/Epoxy Composites for various Particle Size)

  • 고성위;김형진;김재동;김창수
    • 한국해양공학회:학술대회논문집
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    • pp.141-144
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    • 2006
  • In this study, the friction and wear characteristics of pure epoxy and silica-filled epoxy resin composites with average silica particle diameter of $6-33{\mu}m$ were investigated at ambient temperature by pin-on-disc friction test. The cumulative wear volume, friction coefficient and wear rate of these materials against SiC abrasive paper were determined experimentally. The cumulative wear volume tended to increase nonlinearly with increase of sliding distance and depended on diameter of the silica particle for all these composites. The sliding wear tests of the materials demonstrated that the friction coefficient and the wear rate of silica filled epoxy composites were lower than those of the pure epoxy. silica filled epoxy.

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반응표면분석에 의한 고 Cr 철계 오버레이 용접부의 분체침식마모 특성의 연구 (A Study on Solid Particle Erosion Wear Characteristics of High Cr White Iron Hardfacing by Response Surface Method)

  • 이형근
    • Journal of Welding and Joining
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    • v.20 no.4
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    • pp.551-556
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    • 2002
  • Solid particle erosion wear characteristics of high Cr white iron hardfacing were investigated using the erosion wear test method according with the ASTM G76-95. Wear experiments, where the blast angle, blast distance and blast pressure were selected as test variables, were planned and analyzed by response surface method (RSM to evaluate the wear loss statistically and quantitatively. The measured wear losses well coincided with the calculated ones by the experimental equation. The wear loss of high Cr cast iron hardfacing was increased with blasting pressure, but affected in a complicated way by the blasting angle and distance. Erosion wear of high Cr cast iron hardfacing could be well predicted by RSM analysis of wear variables.

Fretting Wear Mechanisms of Zircaloy-4 and Inconel 600 Contact in Air

  • Kim, Tae-Hyung;Kim, Seock-Sam
    • Journal of Mechanical Science and Technology
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    • v.15 no.9
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    • pp.1274-1280
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    • 2001
  • The fretting wear behavior of the contact between Zircaloy-4 tube and Inconel 600, which are used as the fuel rod cladding and grid, respectively, in PWR nuclear power plants was investigated in air. In the study, number of cycles, slip amplitude and normal load were selected as the main factors of fretting wear. The results indicated that wear increased with load, slip amplitude and number of cycles but was affected mainly by the slip amplitude. SEM micrographs revealed the characteristics of fretting wear features on the surface of the specimens such as stick, partial slip and gross slip which depended on the slip amplitude. It was found that fretting wear was caused by the crack generation along the stick-slip boundaries due to the accumulation of plastic flow at small slip amplitudes and by abrasive wear in the entire contact area at high slip amplitudes.

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운전속도에 따른 플라스틱기어의 마멸특성 (Wear Characteristics of Plastic Pinion Against Steel Gear for Different Pitch Line Velocities)

  • 김충현;안효석;정태형
    • 대한기계학회논문집A
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    • v.25 no.11
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    • pp.1720-1729
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    • 2001
  • Wear characteristics of Nylon and acetal pinions against steel gears for different pitch line velocities was studied with a power circulating gear test rig under unlubricated condition. Specific wear rate was measured as a function of tooth number, module, tooth width and total revolution. The worn tooth surfaces were examined with a profile projector. The Nylon pinion showed lower specific wear rate than the acetal pinion. However, the Nylon pinion was fractured at high tooth loads, whereas the acetal pinion exhibited a steady wear behavior. The wear characteristics of Nylon pinion varied significantly with the Pitch line velocity. Wear occurred most severely at the tooth tip and the region immediately below the pitch line of pinion. The dominant wear mechanisms were adhesion and abrasion.