• 한국의류학회지
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• 제25권1호
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• pp.37-49
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• 2001

The purpose of this research was to investigate the influential factors to wear or not to wear \"Hanbok\" in Korean society. Twenty six individuals who wear Hanbok relatively often, and twenty seven individuals who dont were purposively sampled and interviewed for the study by structured depth-interview method. A domain analysis, a method of qualitative study, was employed to find out the influential factors from the results of the depth-intervews. From the analysis, fifteen encouraging or discouraging factors to wear Hanbok emerged and were categorized into five domains, which included \"interpersonal relationship\", \"life-style\", \"image\", \"practicality\" and \"decorative function\". The personal involvement in traditional culture, tradition-oriented family background, good images related to Hanbok, and affordable life-style appeared to be encouraging factors to wear Hanbok. Meanwhile, social norm and role-expectation adjusted to westernized criteria, unaffordable life-style, ill practicality of Hanbok and negative cues associated with Hanbok were the factors influencing people to turn away from Hanbok. The study also revealed complex interactions between these factors explaining individuals choice of wearing or not wearing Hanbok in industrialized modern society of Korea. Some suggestions to promote wearing Hanbok were made based oh the results of this study.wearing Hanbok were made based oh the results of this study.

• 열처리공학회지
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• 제2권2호
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• pp.17-26
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• 1989

This study has been performed to investigate into some effects of the Sursulf treatment time and the traveling speed of surface hardening treatment on the hardness and the wear characteristics by applying the combined heat treating techniques of Sursulf process followed by induction hardening treatment to mild steel. It has been shown that increasing the Sursulf treatment time increases the case depth, but both hardness and wear resistance are not considerably improved. When the combined heat treating technique of high frequency induction heating after Sursulf treatment is applied, an improvement in case depth as well as wear resistance is obtained. In particular, the hardness in diffusion zone is greatly increased due mainly to the formation of martensite and possibly lower bainite. Iron oxides formed during induction heating and subsequent water spray cooling in the outermost part of compound layer may be considered to cause some increases in hardness and wear resistance.

• 한국정밀공학회지
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• 제14권2호
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• pp.58-65
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• 1997

Work rolls used in cold rolling mills must have outstanding wear resistance and very little plastic defor- mation. Thus, these rolls require a higher surface hardness and harding to a greater depth. To meet these requirements, the rolls, in general, have basic chemical composition of 0.7 to 1.0% carbon and 1.0 to 5.0% Cr(chromium), plus a small amounts of special elements, and are subjected to intensive water quenching and tempering at low temperature to provide a surface hardness of over 90 shore. This test results are as follows. Deflection and fracture load of 5% Cr material are than those of 3% Cr material and show flat curve from surface to subsurface. It will be clear that 5% Cr work roll has a superior resisti- bility against wear and abrasion comparing with 3% Cr work roll. The improvement of wear and abrasion in 5% Cr work roll will be achieved by the large amount of wpheroidal carbide. In grindability and polish, 5% Cr work roll will be a little inferior comparing with 3% Cr work roll.

• Nuclear Engineering and Technology
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• 제37권2호
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• pp.201-206
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• 2005

Fretting, which is a special type of wear, is defined as small amplitude relative motion along the contacting interface between two materials. The structural integrity of steam generators in nuclear power plants is very much dependent upon the fretting wear characteristics of Inconel 690 U-tubes. In this study, a finite element model that can simulate fretting wear on the secondary side of the steam generator was developed and used for a quantitative investigation of the fretting wear phenomenon. Finite element modeling of elastic contact wear problems was performed to demonstrate the feasibility of applying the finite element method to fretting wear problems. The elastic beam problem, with existing solutions, is treated as a numerical example. By introducing a control parameter s, which scaled up the wear constant and scaled down the cycle numbers, the algorithm was shown to greatly reduce the time required for the analysis. The work rate model was adopted in the wear model. In the three-dimensional finite element analysis, a quarterly symmetric model was used to simulate cross tubes contacting at right angles. The wear constant of Inconel 690 in the work rate model was taken as $K=26.7{\times}10^{-15}\;Pa^{-1}$ from experimental data obtained using a fretting wear test rig with a piezoelectric actuator. The analyses revealed donut-shaped wear along the contacting boundary, which is a typical feature of fretting wear.

• 한국정밀공학회지
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• 제16권1호통권94호
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• pp.174-181
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• 1999

In this paper the technique to predict tool wear theoretically in shearing process is suggested. The tool wear in the process affects the tolerances of final pans, metal flows and costs of processes. In order to predict the tool wear the deformation of workpiece during the process is analyzed by using non-isothermal finite element program. The ductile fracture criterion and the element kill method are also used to estimate if and where a fracture will occur and to investigate the features of the sheared surface in shearing process. Results obtained from finite element simulation, such as nodal velocities and nodal forces, are transformed into sliding velocity and normal pressure on tool monitoring points respectively. The monitoring points are automatically generated and the wear rates on these points are accumulated during the process. It is assumed that the wear depth on the tool surface is linear function of the lot sizes based upon the known experimental results. The influence of clearance between die and punch upon tool wear is also discussed.

• Tribology and Lubricants
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• 제9권1호
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• pp.38-44
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• 1993

The present study was undertaken to investigate the dry wear characteristics of die steel STD 11 for cold molding. The wear test was experimentally carried out under different conditions using a wear device, which was made in laboratory, and in which annular surfaces of wear testing specimens wear rubbed in dry sliding condition with varying the sliding speed, contact pressure, and sliding distance. The wear loss by variation of sliding speed was much in 0.3 m/sec and less in higher speed range above its sliding speed according to formation of the boundary lubrication film. The critical sliding speed with maximum value of the specific wear rate switched over to lower speed side according. as contact pressure increased. The critical sliding distance was increased with decrease in oxidation reaction velocity. The depth below subsurface showing maximum hardness (Hv) came out at the position, $60 \mu m$, of the maximum shear stress due to strain hardening.

• 대한기계학회논문집A
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• 제27권11호
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• pp.1881-1888
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• 2003

This study show a numerical method to predict roll wear in the roll forming process. Archard's wear model was reformulated in an elemental form to predict volume of roll wear and then wear depth on the roll was calculated using the results of finite element analysis. Abrasive wear occurs at contact area in the roll forming process and the results of simulation are compared with experimental data in production line. The wear simulation approach with 3-D FEM program for roll forming process, SHAPE-RF is in good agreement with it in tendency.

• Tribology and Lubricants
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• 제15권2호
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• pp.141-149
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• 1999

Fracture, fatigue and wear characteristics of Al-Si alloy used for compressor are experimentally studied. Plane strain fracture toughness test is carried out using three point bending specimen. Fatigue test is performed under constant loading condition and wear test is carried out as a function of sliding velocity and applied load. To obtain the crack propagation characteristics and wear mechanism of Al-Si alloy, fracture and worn surfaces are investigated using SEM. It is verified that fracture and fatigue strength of Al-Si alloy are improved by the fine microstructure of alloy. The wear behavior and specific wear amount of Al-Si alloy are not dependent on the microstructure but on a function of the silicon content. Anodizing on the surface of Al-Si alloy, surface hardness and wear characteristics are improved.

• Tribology and Lubricants
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• 제35권4호
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• pp.244-266
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• 2019

The purpose of this study is to estimate the wear volumes of engine journal bearings operating at variable angular velocity of a shaft in the beginning of firing start-up cycle. To do this, first we find the potential region of wear scar on engine journal bearings where the applied bearing load and crank shaft velocity are variable. The potential wear regions are discovered by finding minimum oil film thickness at every crank angle existing below most oil film thickness scaring wear (MOFTSW) obtained based on the concept of the centerline average surface roughness. Then we calculate the wear volume from the wear depth and two wear angles decided by the magnitude of each film thickness lower than MOFTSW at every crank angle. The results show that the expected wear region is located at a few bearing angles after and/or behind the upper center of a big-end bearing and the lower center of a main bearing. And the real wear region is similar to the estimated wear region. Further we find that the wear scar on an engine journal bearing may occur at re-starting time after switch-off of a start motor especially under the condition of high oil temperature.

• 소성∙가공
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• 제26권3호
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• pp.137-143
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• 2017

In this study, a wear test method was proposed to predict the wear life of the CrN layer coated on the surface of the press tools for manufacturing the auto-parts with ultra high strength steel (UHSS) with a tensile strength of 1.5 GPa. The pin-on-disc type wear test was carried out to confirm the feasibility and the reproducibility of the wear amount according to the test conditions such as the normal force, the sliding velocity, and the sliding speed. The test conditions were obtained from the finite element stamping analysis and the wear simulation. With the wear amount from the wear test, a prediction model of the wear depth in the CrN coating layer was proposed according to the test conditions with the design of experiments such as Taguchi method and the response surface method. The derived prediction model was then compared to the result of the Archard wear model, fully describing that the proposed model can effectively predict the wear life of the press tools for the auto-parts with UHSS.