國산構造용 鋼板 의 水中熔接性 과 熔接强度 特性

오세규,남기우 대한기계학회 1983 대한기계학회논문집 Vol.7 No.3

Underwater welding by a gravity arc welding process was investigated by using six types of coated electrodes and SM41A steel plates of 10 mm thickness as base metal and it was ascertained that this process may be put to practical use. Main results obtained are summarized as follows: 1. Angle of electrode affects no influence on bead appearance and the proper range of welding current and diameter of electrode for the high titanium oxide type is relatively wider than that for the ilmenite type. And the lime titania type, high titanium oxide type and ilmenite type of domestic coated arc welding electrodes of .phi.4 mm could attain the soundest underwater welded joints which contain no welding imperfection. 2. According to macro-structure, micro-structure and hardness distribution inspectionson underwater welded joint, the area between the HAZ and the surface of the weld in neighbourhood of the bond has the maximum hardness value. The structure of these parts is martensite and bainite. Other parts contain mocro-ferrite, micro-pearlite structure, which contain soundness of welded joint free from weld imperfection. 3. On consideration of both tensile strength of more than 100% joint efficiency and sufficient impact value, the welding condition which can get optimal welding strength is heat input of 1,400-1,500 J/mm, current of 200-215 ampere (voltage of 32-33 volts) in the case of lime titania type electrode. 4. Underwater welding strength (tensile strength, impact strength) depends on heat input (or current) quantitatively and they have the relationship of parabolic function. Each experimental equation has a high reliability and its percent of mean error is 4.14%. 5. It is suggested that the optimal design of weld strength by welding condition (current, heat input) could be utilized for a quality control of underwater welding.

오르프 학습법에 의한 음악의 지도

오세규 淸州敎育大學校 2002 論文集 Vol.39 No.-

전자빔 리소그래피에서의 근접효과 보정을 이용한 패턴 제작에 관한 연구

오세규,김동환,김승재,Oh, Se-Kyu,Kim, Dong-Hwan,Kim, Seung-Jae 한국반도체디스플레이기술학회 2009 반도체디스플레이기술학회지 Vol.8 No.2

This study describes the electron beam lithography pattern fabrication using the proximity effect correction. When electron beam exposes into electron beam resist, the beam tends to spread inside the substance (forward scattering). And the electron beam reflected from substrate spreads again (back scattering). These two effects influence to distribution of the energy and give rise to a proximity effect while a small pattern is generated. In this article, an electron energy distribution is modeled using Gaussian shaped beam distribution and those parameters in the model are computed to solidify the model. The proximity effect is analyzed through simulations and appropriate corrections to reducing the proximity effect are suggested. It is found that the proximate effect can be reduced by adopting schemes of dose adjustment, and the optimal dose is determined through simulations. The proposed corrected proximity effect correction is proved by experiments.

오르프 교수법에 의한 기악실기

오세규 淸州敎育大學校 2003 論文集 Vol.41 No.-

연구논문초록(’81-’90) : 배관방식용 유전양극의 접지전지 특성에 관한 연구

오세규,임우조,전대희 한국부식학회 1991 Corrosion Science and Technology Vol.20 No.1

This paper used for designing the grounding cell has reached the following conclusion as the results of an experimental study on the grounding cell characteristics of galvanic anodes for corrosion protection of pipings. The galvanic anode have three kinds such as zinc alloy anode, aluminium alloy anode and magnesium alloy anode, which are widely used on cathodic protection for all metals structures in water or under ground, and Silicon diodes are used on the insulation joint protective device : 1) in order to drain a certain electric current from a certain impressed voltage, the active area of anode should be increased but the space between anodes should be lessened as possible in the case of the environmental condition of high specific resistance. 2) Among these three kinds of galvanic anodes, when the specific resistance of the environment was bellow 750Ω. cm, zinc alloy anode was best, and when above 750Ω cm, magnesium alloy anode used for grounding cell characteristics was the best, but aluminium alloy anode in all the environments reduced grounding cell characteristics to the lower grade than those of zinc alloy anode. 3) The impressed voltage at which drainage current density begins rapidly increasing becomes lowered in all anodes according as the specific resistance of the environment increases. 4) The approximate relations of drainage current density and impressed voltage on the grounding cells of galvanic anodes are as follows : E_(Za)=log(5.2475/ρ^(0.0672))+64×1-^(-7)(10L)^(0.5112). ρ^(0.9006), i E_(Al)=log(4.8889/ρ^(0.0437))+66×10^(-7)(10L)^(0.5487). ρ^(0.9235), i E_(Mg)=log(4.152/ρ^(0.1234))+1514×10^(-7)(10L)^(0.0681). ρ^(06019), i 5) Impress voltage which have the rapid increase rate of the insulation joint protective device of silicon diode was higher than of the grounding cell of galvanic anodes, but the constant impressed voltage in the case of the former was higher than in the case of the latter.

A Study on Temperature Distribution in Inertia Welded Joints of SAE 1020 Steel B

오세규 釜山工業大學校 1976 論文集 Vol.17 No.-

밸브材料의 摩擦熔接에 關한 硏究(第2報) : On Determining the Optimum Welding Condition for Joining the Exhaustive Valve Materials SUH3-CRK22 排氣밸브材料 SUH3-CRK22의 壓接을 爲한 最適 熔接條件 決定을 中心으로

吳世奎 釜山工業大學校 1976 論文集 Vol.17 No.-

This is the continuing study after "Study on Friction Welding of Valve Materials(On Improving the Friction Weld Quality for Exhaustive Valve Materials SUH3-SUH31.)" This study deals with the experimental results of friction welding, its reliability and their mechanical properties to obtain the optimum welding condition for joining the heat resisting steel silchrome SUH3 as a valve stem to the engine exhaustive valve steel CRK22 as a valve head. The results obtained by the experiments are as follows: 1) The optimum welding condition of SUH3 to CRK22 in order to attain sufficiently high tensile strength, better joining reliability and higher productivity was experimentally determined as the following; Rotating speed=3000rpm, frictional heating pressure p1=8㎏/㎟; upsetting pressure p2=22㎏/㎟, frictional heating time t1=4.9∼5.2 sec, upsetting time t2=2 sec., total upset=7.3∼7.6 ㎜. 2) In tensile test after heat treatment(750℃×1hr., air cooling,) the weld joint was much stronger(about 2.5% more increase max.) than the parent material of SUH3 and the fracture occurred at the SUH3 parent. 3) In the reliability test of friction welding, when the 24 pairs of specimens of SUH3 and CRK22 were continuously friction-welded at the same welding condition(speed=3000 rpm, p1=8㎏/㎟, p2=22㎏/㎟, t1=5.5sec, t2=2.0sec) on the same friction welder, the upset distribution was 0.8㎜, the compression rate versus total upset of SUH3 specimens was 42∼47%, and the deviation of the joints was 0.05∼0.17 ㎜. 4) Hardness of weld interface was more increased according to the radial direction from the center, and a peak and hollows and the residual stress found in micro-vickers hardness distribution on the both sides of SUH3 and CRK22 near the weld interface became almost uniform after heat treatment(750℃×1hr., air cooling), just as in the case of SUH3-SUH31. 5) And microscopic examination of the weld joints friction-welded under the above optimum condition revealed that the weld zone is very narrow and has a fine grained intermixed structure with no melt product or grain growth and without any welding defects.

Thermal SEM의 성능 평가를 위한 계량적 프레임워크

오세규,김우제,김동환 대한산업공학회 2007 대한산업공학회 추계학술대회논문집 Vol.2007 No.11

밸브재료의 마찰용접에 관한 연구(제2보)

오세규 釜山工業大學校 1976 論文集 Vol.17 No.-

軸비틀린振動에 依한 Diesel Engine의 二次的 振動

吳世奎 釜山工業大學校 1969 論文集 Vol.9 No.-

This report describes the secondary vibration of a diesel engine which i formed by the torsional vibration of shafts, and the theory of the occurrence and its characteristics of the vibration which is induced by the quantity of crank pin mass. And this is described theoretically by proper calculation. The quantity of engine crank pin mass varies the revolving speed according to the torsional vibration of rotating shafts, and then produces a force to let vibration occur by which the centrifugal force and the tangential inertia force are varied. It has been found that this force causes to vibrate the rotating shafts and the engine, and that this vibration occurs at (n+1) and (n-1) degrees if the degree of the torsional vibration is n. And found by calculation, the secondary force made by the torsional vibration is not so great and it does not matter at all when the amplitude of the torsional vibration is small, but, if the engine is operated at a damper breakdown or near a point of the resonance of torsional vibration, much greater vibration will occur. So, to prevent the engine efficiency from dropping lower by such resonance of torsional vibration, some consideration should be taken. Thus, when the vibrations of engine parts are measured with a vibration gage, if any vibration of expected degree is found, the vibration at (n+1) and (n-1) degrees occurring by the torsional one should be surely examined and the instant countermeasure for the torsional vibration should be taken.