[論文] 표면 Rolling시 가압력이 표면 조도에 미치는 영향

강명순(M.S.Kang),김희남(H.N.Kim) 한국자동차공학회 1987 오토저널 Vol.9 No.5

The surface rolling method which is one of the plastic deformation processes increases the surface roughness with reduction of diameter and hardness.<br/> In this study, three NACHI 6000 ZZ bearing were used for surface rolling tool on a mild steel.<br/> The following results have been obtained with the mild steel.<br/> I) The load is major factor in getting fine surface roughness of roller finishing after grinding. The optimal surface roughness of SS41 steel can be obtained at the contact pressure of 21Okgf/㎠.<br/> But, Better surface roughness can not be expected, Due to flaking phenomena at more than 300kgf/㎠ of contact pressure.<br/> 2) At the contact pressure range of 2OOkgf/㎠~210kgf/㎠ for optimal surface roughness,The surface hardness increased to Hv200~Hv240 from Hv 125 before surface rolling.<br/> 3) Within the diameter variation of 13㎛ the surface roughness and the surface hardness were increased, but out of variation of 14㎛, The surface roughness become worse and the surface hardness was increased.

[論文] 표면 Rolling시 작업조건이 표면조도에 미치는 영향

강명순(M. S. Kang),김희남(H. N. Kim) 한국자동차공학회 1986 오토저널 Vol.8 No.3

The surface rolling method which is one of the plastic deformation processes increases the surface roughness and hardness of materials.<br/> In this study, three NACHI 6000 ZZ bearing were used for surface rolling tool on the mild steel and high carbon steel.<br/> The purpose of this study is to investigate the effects of rolling speed, feed rate and contact pressure on the surface roughness.<br/> The following results have been obtained with the mild steel and high carbon steel.<br/> I. The roller finishing method has increased surface roughness from 2.4㎛Ra at initial ground surface to 0.17 ㎛Ra 0.4 ㎛Ra.<br/> 2. The contact pressure has influenced greatly on the surface roughness. There is an optimal contact pressure.<br/> 3. As the rolling speed and the feed rate decrease, the surface roughness improves.<br/> 4. The optimal contact pressure for the good surface roughness of SS40 and STC 3 has been at 213 Kgf/Cm² and 220 Kgf/Cm² respectively.

[論文] 炭素鋼의 機械的 性質을 改善하기 爲한 이온室化 處理의 應用에 關한 硏究

강명순(M.S.Kang),윤종학(J.H.Yoon),이원평(W.P.Lee) 한국자동차공학회 1987 오토저널 Vol.9 No.2

This thesis is to improve the mechanical properties of carbon steel by the ion-nitriding, and post-heat treatment.<br/> The structures of ion-nitrided SM45C steel were changed to martensite by quenching from 730℃ and 8OO℃.<br/> And then a few of the quenched specimens was tempered at 200℃ for 120 min.<br/> The emphasis in this study is focussed on Comparison of hardness and fatigue strength with the ion-nitrided steel.<br/> The results obtained are summerized as follows.<br/> 1. To improve the hardness and fatigue strength of ion-nitrided steels, it is effective to under.<br/> take diffusion treatment for a short time at the austenite temperature (8OO℃).<br/> 2. If ion-nitrided steel is heated for a long time at high temperature, de-nitriding occure. <br/> 3. The quenching treatment after nitriding on the carbon steel is necessary to improve the mechanical properties of the steels.

[論文] Acoustic Emission을 利用한 工具破損 및 Chipping의 探知에 關한 硏究

강명순(M. S. Kang),한응교(E. K. Han),김기중(K. C. Kim),최성주(S. J. Choi) 한국자동차공학회 1986 오토저널 Vol.8 No.3

This study was investigated the feasibility of AE application on in-process detection of tool fracture and chipping.<br/> Carbon steel SM45C workpiece with longitudinal slots was turned interruptedly on a lathe.<br/> AE RMS signal at tool fracture was observed and also the tangential force and the feed force were measured to compare with AE RMS signal. The sudden high level AE signal was observed at the time of tool fracture, the levels of tangential force and the feed force at the time of fracture decrease considerably.<br/> In chipping, high level AE signal was observed but there were no changes of cutting force.<br/> Peak AE RMS squared is proportional to the area of toolfracture and resultant force.<br/> Fracture model of tool fracture is proposed as<br/> v_P= C₁E₁F (△A)^0.5<br/> and peak AE RMS shows strong correlation with the fracture parameter F(△A)^0.5.

[論文] 2차원 절삭과정에서의 Acoustic Emission과 절삭 파라미터 사이의 관계

최성주(S.J.Choi),강명순(M.S.Kang) 한국자동차공학회 1987 오토저널 Vol.9 No.2

The objective of this study is to establish the comprehensive analytical relationship between acoustic emission and fundamental parameters of the orthogonal cutting process.<br/> The sources of acoustic emission in the orthogonal metal cutting process was identified as deformation in the shear zone and sliding friction at the chip-tool interface.<br/> The validity of this relationship is evaluated by a series of tests varing cutting speed and rake angle for A16063 tube. Strong dependence of the RMS voltage of acoustic emission on cutting speed and rake angle was observed.<br/> It was also found that the percentage contribution of AE energy at each zone for the total AE activity is constant in accordance with the change of cutting speed.<br/> The relationship between the RMS of acoustic emission and the fundamental cutting parameters was modified in order to be utilized independent of rake angle.

[論文] ION 窒化에 있어 添加 炭素量이 殘留應力에 미치는 영향

김희송(H.S.Kim),강명순(M.S.Kang) 한국자동차공학회 1982 오토저널 Vol.4 No.2

This paper deals with residual stress characteristics of ion-nitrided metal which is primaril­ly concerned with the effects of added carbon content in gas atmosphere.<br/> A small optimal amount of carbon content in gas atmosphere increase compound layer thickness, as well as to increase diffusion layer thickness and hardness.<br/> The residual stress and deflection of the specimens was measured in various elevated temperature at the surface of ion-nitrided metal and the internal stress distribution was cal-culated.<br/> It is found that compressive residual stress at the compound layer is largest at the com­pound layer, and decreases as the depth from the surface increases.

[論文] 유리섬유 강화 플라스틱(GFRP) 절식시의 공구마멸특성(공구재종의 영향)

이원평(W.P.Lee),강명순(M.S.Kang) 한국자동차공학회 1988 오토저널 Vol.10 No.1

A turning (facing) test on Glass Fiber Reinforced Plastics was performed with several tool materials, e.g., cemented carbides, cermet and ceramic, and the wear patterns and wear rate were analyzed to clarify the relation between physical(mechanical) properties and flank wear of cutting tool. The main results are obtained as follows:<br/> (1) When cutting speed is increased, the flank wear in every tool material grows the abnormal wear in the shape of triangle at a certain speed, i.e., a critical speed.<br/> (2) When cutting speed is increased, the wear rate in experimental tool material starts to increase remarkably at a critical speed.<br/> (3) The thermal conductivity among the properties of the tool material and the thermal crack coefficient of it are almost in proportion to the critical speed.<br/> (4) The order of performance in tool materials for cutting GFRP is K 10, M 10, P 20, TiC, CB.

[論文] 스프링형 블랭크홀더 시스템의 디프드로잉 가공에서 다이면 윤활효과에 관한 연구

이종국(J.K.Lee),강명순(M.S.Kang) 한국자동차공학회 1989 오토저널 Vol.11 No.3

The purpose of this paper is to obtain the effect of die lubrication in deep drawing process. The flange wrinkling is analysed by a moment equilibrium method in order to apply the opti­mum blankholding force to the blank. The experiment has been carried out with the high stiff­ness spring- type blankholder system.<br/> As the result, blankholding pressure is determined in terms of variables in deep drawing process. In the range of frictional coefficient which has been found in this experiment, there was a little difference in required blankholding force but a great difference in drawing force. It was found that the stiffness of blankholder was the major factor which influences on flange wrinkling in spring- type blankholder system.

[論文] 스프링형 블랭크홀더방식의 디프드로잉 가공에서 다이 윤곽반경이 성형성에 미치는 영향에 관한 연구

이종국(J. K. Lee),강명순(M. S. Kang) 한국자동차공학회 1989 오토저널 Vol.11 No.4

The major purpose of this paper is a strudy on the effect of die profile radius on the formabi-lity of spring-type blankholder system in deep drawing process. By drawing the various materials,formability is studied by means of checking the drawing force, blankholding force variation,limiting drawing ratio and wall wrinkling phenomenon.<br/> As the die profile radius increases, the maximum drawing force and maximum blankholding force decrease regardless of lubrication condition. Because better lubrication induces blank-holding force to rise, spring type blankholder system is better to protect flange wrinkling phen-omenon than constant pressure type. And wall wrinkling phenomenon was not detected in ex-perimental die radius range, so the Miyakawa's upper wrinkling limit is understimated in case of material tested.

[論文] 유리纖維 强化 플라스틱 切削에서의 工具磨滅特性

이원평(W.P.Lee),윤종학(J.K.Yoon),강명순(M.S.Kang) 한국자동차공학회 1987 오토저널 Vol.9 No.5

This paper is a study on the effect of the cutting speed on the tool wear in turning of the glass fiber reinforced plastics.<br/> The wear behavior of cutting tool is studied by means of turning, changing the cutting speed and feed in the wide range. Moreover, the theoretical model applicable to the cutting speed of wide range is analysed.<br/> The main results obtained are as follows:<br/> The relation between the tool wear and the cutting speed is divided into three range in case of the constant cutting distance.<br/> 1) At the low cutting speed, the tool wear is independent of the cutting speed, but de­pendent mainly on the contact length between tool and glass fiber (1st range).<br/> 2) At the high cutting speed, the tool wear is independent of the contact length, and dependent on the cutting speed only (2nd range). The tool wear increases in proportion to the cutting speed.<br/> 3) At the higher cutting speed than the speed in the 2nd range, the tool wear is inde­pendent both of the cutting speed and the contact length (3rd range).<br/> 4) In the 3rd range, tool flank wear is constant and is observed that only the wear of cutting edge increases.