• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.08a
• /
• pp.272-278
• /
• 1999

Tungsten Carbide(WC) Roll is widely used in finishing stands of wire rod mill. This report is about the manufacturing method of WC roll with excellent wear resistance. To enhance wear resistance, WC content has been increased to the maximum extent while binder content such as Co, Ni, Cr has been minimized. Part of WC is replaced with TiC having more wear resistant than WC. WTiC powder has been used to prevent weight unbalance resulting from the difference of specific weight when adding TiC. The roll manufactured by this method, is having more wear resistance than the existing rolls when applying to the final stand of the finishing mill. This report shows that WC is the critical factor of wear resistance in WC rolls and an approprite amount of TiC effects wear resistance and when adding TiC, using WTiC powder is better.

• Journal of Power System Engineering
• /
• v.5 no.3
• /
• pp.88-94
• /
• 2001

Stellite 12 alloy-powders were overlaid on 410 stainless steel valve seat using plasma transferred arc(PTA) process. Variation of the microstructure, hardness, wear and corrosion of overlaid deposit with current change was investigated. The deposit showed hypoeutectic microstructure, which was consisted of primary cobalt dendrite and networked $M_7C_3$ type eutectic carbides. As current increased, the amount of eutectic carbide decreased and its dendritic secondary arm spacing increased. Hardness of the deposit was decreased with increase of current. Stress relief heat treatment at $600^{\circ}C$ for two hours resulted in slight increase of hardness in the deposit and showed uniform hardness distribution in base metal without any hardened layer in HAZ. Specific wear decreased with increase of sliding distance. The deposit of high hardness with a lot of eutectic carbide showed relatively low specific wear. Initial corrosion current density of the deposit in 0.1N sulfuric acid was lower than those of 410 stainless steel, and showed a little variation with PTA current.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.4 s.152
• /
• pp.582-594
• /
• 2006

The purpose of this study were to develop snow-board lower wear with improved functionality. The study consisted of figure out appropriate ease amount of snow-board lower wear and make products by applying it to pattern design. The results of this study were as follows: On the basis of the analysis of snow-board lower wear on market, 2 pieces of experimental snowboard lower wear were designed, produced, and evaluated the patterns of with different ease, and snowboard lower B for experiment was proved to be better. Snowboard lower wear was produced and evaluated for experiment 2 by giving additional ease to specific parts. Therefore experiment 2 was presented pattern, ease, and size of snowboard lower wear with improved functionality. Sizes and ease of snow-board lower wear for presentation. waist circumference - 96.0cm(l6.4cm, 17.1%); hip circumference - 127.0cm(31.3cm, 24.4%); pants length - 112.0cm(9.6cm, 8.6%); crotch length - 90.0cm(26.8cm, 36.4%); thigh circumference - 78.0cm(23.4cm, 30.0%); knee circumference - 62.0cm(24.7cm, 39.8%); turnup circumference - 62.0cm(36.0cm, 58.1%). Above mentioned sizes and ease of lower wear are medium size(M) for male.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.11
• /
• pp.131-137
• /
• 2009

A pair of connectors for transferring torque is widely used in various types of a mechanical system. By the repetition of mechanical contact between a pair of connector, wear occurs easily. This kind of defect sometimes can cause a serious problem of health in case of the connector is used in a refrigerator. In this work, the material combination of connectors was experimentally studied to reduce the amount of wear; for the combination of connectors, various types of engineering materials including polyacetal, polycabonate, stainless steel (STS-304), NiP coated STS-304, and STS-310 were evaluated to check each wear behavior. Also an effective method of wear test was suggested for precise controlling of wear conditions such as contact area, contact force, and relative motion speed. From the test results, it was found out that a pair of polyacetal to STS-304 and STS-310 showed the lowest specific wear rates among other pairs.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2001.06a
• /
• pp.81-88
• /
• 2001

To study the influence of the shape of contacting bodies (especially the end profile) on slip regime, wear test is conducted in the case of the contact between tube and support. Two different end profiles of the support are used such as truncated wedge and rounded punch. During the test, 10, 30 and 50 N are applied as normal force and slip displacement varies between 10-200 $\mu\textrm{m}$. The tube and the support specimens are made of Zircaloy-4 and a specially designed wear tester is used. Tests are carried out in air at room temperature. Wear on the tube is examined by measuring microscope. Partial and gross slip regimes are classified from the observed wear shape. Surface roughness tester is also used to measure the wear depth and contour, from which wear volume is evaluated. The transition from partial to gross slip is also investigated by investigating the considerable increase of wear volume. From the result, the boundary between the partial and the gross slip is newly determined in the conventional fretting map for the present specific contact configuration. Since the transition is related with the amount of energy dissipation from the contact surface so is wear, it is regarded that wear can be restrained by designing a proper shape of support.

• The International Journal of Costume Culture
• /
• v.7 no.2
• /
• pp.135-150
• /
• 2004

The purpose of this study is to explicate the contemporary concept of the term 'sportswear' by studying the history of sportswear tradition in America where sportswear was first established and developed. American sportswear originated from some functional clothes made for specific sports during the 19th century. Early in 20th century, there occurred many significant events in America while Americans were undergoing two successive world wars. First of all, due to the wars, women's role in labor force became so significant that their social status was enhanced remarkably. With economy growing every decade, the amount of leisure time for American people substantially increased and, therefore they could develop their leisure activity culture. All these changes made Americans demand the need for comfortable and functional clothes suitable for their changed way of life. In response to this demand, the sportswear tradition became mature due to the contribution by many creative All-American designers, most of whom have made their active contributions since 1970s. Now the sportswear, which used to be designed for specific sports, developed into casual wear in general with its extended definition. The contemporary concept of sportswear is no longer limited to those clothes for specific sports. Sportswear has now become more like a casual activity wear which all classes of people can enjoy in their life. Since the concept and scope of sportswear is extended to a great degree today, we need a new professional term to correctly express the extended nature of these contemporary clothes.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.29 no.2
• /
• pp.254-266
• /
• 2005

The purpose of this study were to develop snow-board upper wear with improved functionality. The study consisted of figure out appropriate ease amount of snow-board upper wear and make products by applying it to pattern design. The results of this study were as follows : First, The results of examined the difference between naked body measurements of and basic wear. According to motion, chest circumference(4.7cm, 5.1%), back width(8.9cm, 20.7%), and waist back length(8.0cm, 18.3%) increased. Around the elbow the length increased by 4.4cm(21.9%) when it was bent 90 degrees, while it increased by 6.0cm(29.8%) when it was bent to the full(145 degree). Second, 3 snow-board upper wear were selected and evaluated their appearance, comforts, and functionality, and that of the biggest margin proved to be the best. Eases necessary for motion proved to be insufficient especially in neck, arm and wrist parts of upper clothing. Third, on the basis of the analysis of snow-board upper wear on market, 2 pieces of experimental snowboard upper wear were designed, produced, and evaluated the patterns of with different ease, and snowboard upper wear B for experiment was proved to be better, Fourth, Snowboard upper wear was produced and evaluated for experiment 2 by giving additional ease to specific parts. Therefore experiment 2 was presented pattern, ease, and size of snowboard upper wear for with snowboard upper wear with improved functionality.

• The Korean Journal of Ceramics
• /
• v.2 no.4
• /
• pp.226-230
• /
• 1996

A small amount of fine particle graphite was added to $\alpha$-SiC and $\beta$-SiC having certain particle distributions, and they were mixed clay and frit. After forming, they were sintered at 140$0^{\circ}C$ for 3 hours. Tribological properties of sintered $\alpha$-SiC-$\beta$-SiC-graphite-clay (frit) system showed that kinetic friction coefficient was 0.108, specific wear rate was 1.3${\times}10^-8\;mm^2$.$kgf^1$, and torque was 0.01kgf.cm at the wrench torque of 100 kgf.cm.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.885-886
• /
• 2006

Significant advances in mechanical testing for hard materials are discussed in this paper. There are three specific areas that are covered. In the measurement of fracture toughness factors such as the control of slow crack growth to produce strating cracks, and evaluating reproducibility and repeatability of tests have been recently examined. The miniaturization of tests reduces the amount of material that is used in testing, improves the throughput of tests, and also improves cost effectiveness. New techniques such as stepwise testing and micro scratch testing have contributed to significant additions to the knowledge of the wear mechanisms that operate in these materials.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.17 no.2
• /
• pp.3763-3771
• /
• 1975

This study was attempted to investigate the changes of specific fuel consumption, compression pressure and power output, consequently to obtain basic data on farm kerosene engine. The samples which are used in this study are a 4 cycle water cooled korosene engine for the use of K6-CT83 power tiller and a 4 cycle air-cooled kerosene engine for the use of G5L-3A water pump. The Korean Industrial Standards (K.S)KS-B 6002 "Test code of small internal combustion engine" was referred in carrying out this study, and its results are as follows. 1. According to load increasing, the speific fuel consumption of the engines generally decreases, however, in case of 10% over-loading it increases. 2. As a result of full load consecutive operation, according to passing of operating time, the amount of wear generally increases, consequently the speific fuel consumption also increases, and inversly the compression pressure decreases. 3. The changes of specific fuel consumption and compression pressure were closely related with time of piston ring exchange, and periodically about 100 hours the engines show the increase of specific fuel consumption and the decrease of compression pressure. 4. After about 300 hours, although the engine had new piston rings, the specific fuel consumption increase, consequently the engine needs boring. In actual use, it is impossible to operate consecutively on full load, therefore the boring time of engine is expected to come later.