이종강관 마찰용접의 소성변형 중 발생된 초기 AE양이 용접품질 제어에 미치는 영향에 관한 연구

오세규,김동조,정락기 대한용접접합학회 1983 대한용접·접합학회지 Vol.1 No.2

Both in-process quality control and reliability of the weld is one of the major concerns is applying friction welding. No reliable nondestructive monitoring method is available at present to determine the weld quality particularly in process of production. So that, this paper presents an experimental examination and quantitative analysis for the effects of initial acoustic emission(AE) counts on the weld strength relating to the rotating speed as a new approach which attempts finally to develop an on-line quality monitoring system design for friction welds using AE techniques. As one of the important results, it was well confirmed that the initial AE counts occurring during plastic deformation period of welding were quantitatively correlated with reliability at 95% confidence level to the joint strength of welds, tube-to-tube (SM 20 C to STS 304) and then an AE technique using the initial AE counts can be reliably applied to in-process strength monitoring of the weld.

노후공동주택 리모델링 사업단지의 거주민 선호도

오세규,김동우,김용,김주희 한국건축친환경설비학회 2018 건축환경설비 Vol.12 No.3

초장파에 의한 이종재 마찰용접 강도해석 가능성에 관한 연구

오세규,김동조 대한용접접합학회 1986 대한용접·접합학회지 Vol.4 No.2

Friction Welds are formed by the mechanisms of diffusion as well as mechanical inter-locking. The severe plastic flow at the interface by the forge action of the process brings the subsurface so close together that detection of any unbounded area becomes very difficult. No reliable method is available so fat to determine the weld quality nondestructively. The paper presents an attempt to determine weld strength quantitatively using the ultrasonic pulseecho method. The new approach calculates the coefficient of reflection based on measured amplitudes of the echoes. This coefficient provides a single quantitative measurement which involves both acoustic energy reflected at the welded interface as well as transmitted across the interface. As a result, it was known that the quantitative relationship between the coefficient and the weld strength (torsional strength) could be drawn.

TMCP강의 습식수중 아크 용접성에 관한 고찰

오세규,김민남 대한용접접합학회 1987 대한용접·접합학회지 Vol.5 No.4

The feasibility of underwater wet arc welding process is experimentally investigated by using high titanium oxide type electrodes and TMCP steel plates as base metal. It is assertained the tis process may be put to practical use. Main results are summarized as follows; (1) Sound underwater weld can be obtained by skilled welding operator, if proper welding conditions are selected. (2) In underwater wet arc welding process, the mechanical properties of HAZ are depend upon welding condition and the optimum welding condition can obtained. (3) The maximum hardness in the HAZ of TMCP steel plates is increased significantly in this welding process.

마찰용접된 Engine Valve용강 SCr4-SUH31 및 SCr4-SUH3의 열처리에 관한 연구

오세규,O, Se-Gyu 선박안전기술공단 1980 漁船 Vol.4 No.-

무직카 픽타와 관련한 후기 르네상스 다성음악의 비교 분석

吳世奎 漢陽大學校 音樂硏究所 1993 音樂論壇 Vol.7 No.-

선용 강판 수중용접부의 인장 구속 균열 특성에 관한 연구

오세규,강문호,김민남 한국마린엔지니어링학회 1987 한국마린엔지니어링학회지 Vol.11 No.3

Generally the factors affected largely by the cold cracking sensitivity of the weld are the quantity of the diffusible hydrogen, the brittleness and hardness of the bond area and the tensile restraint stress. These factors have relation each other, and if we can reduce one of these factors, it becomes instrumental to the root cracks prevention of weld. This study deals with the gravity type-underwater-welding of KR Grade A-3 marine steel plate using E4303 welding electrode in order to compare wet-underwater-welding with in-air- welding, resulting in obtaining the tensile restraint characteristics, the hardness distribution, the quantity of diffusible hydrogen and the macro- and micro-crack properties in both underwater and in-air welds. The main results obtained are as follows: 1) The quantity of diffusible hydrogen measured for 48 hours is about 18cc/100g-weld-metal for the in-air-weld of one pass and about 48cc/100g-weld-metal for the underwater-weld of one pass which is about 3 times penetration of diffusible hydrogen compairing with the case of the in-air-weld. However, it was experimentally confirmed that, by the multi-pass welding of 2 to 5 passes, the diffusible hydrogen in the underwater weld metal can be reduced as much as 27 to 49%. 2) The hardness of the weld metal indicates the highest value in the heat affected zones of underwater weld for more rapid cooling rate, resulting in the higher sensitivity of cold cracking. So, it is desirable to soften the higher hardness in the HAZ by tempering effect such as the multi-pass welding in the underwater welding. 3) At the bond vicinity of the underwater weld HAZ, micro cracks were found as resulted by both more rapid cooling rate and more diffusible hydrogen and also by the stress corrosion cracking under the tensile restraint stress in the underwater. But this could be prevented by the tempering effect of the following weld bead such as the multi-pass welding.

摩찰壓接에 關한 考察(1) -Inertia 법을 중심하여-

오세규 대한기계학회 1980 大韓機械學會誌 Vol.20 No.6

이상과 같이 마찰압접법(inertia법)의 특성과 응용 및 그 경제성의 우수함을 논하였고 응용 실 예를 열거함으로써 마찰압접의 신속한 국산화에 조금이라도 기연하고자 하였다. 선진국에서는 고압용기나 산업용재료의 용접에도 관성압접을 응용할 만큼 그 응용범위가 넓으며, 오늘날 우 리 나라의 기계공업도 크게 발달되어 기계생산품의 질적향상과 생산원가절감을 통한 국산기계 류의 해외시장 개척 및 경쟁윤리를 위해 우리나라에도 마찰압접법이 응용되어야 할 때가 왔다고 확신한다.

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.

摩擦熔接機械 의 自動생산品質制御 實時間 評價

오세규,임우조,김형자 대한기계학회 1985 대한기계학회논문집 Vol.9 No.6

본 연구에서는 기계공업 분야에서 많이 이용되는 구조용 합금강인 Cr-Mo강 (SCM4)과 쾌삭강(SUM31, SUM24L)과의 이종강봉 마찰용접에서 소성변형중에 발생된 초 기 AE량과 용접 품질(강도)제어 사이에 역시 정량적 상관성이 성립함을 용접 회전수, 용접에너지, 용접 업셋 및 용접 시간 등을 매개 변수로 하여 실험과 계산을 통해 입증 하고, 이를 상관식의 95% 신뢰성을 확인한 후, 본 연구의 최종 목적으로서, 마찰용접 평가의 자동화가 이루어지게 하였다. Both in-process quality control and high reliability of the weld is one of the major concerns in applying friction welding to the economical and qualified mass-production. No reliable nondestructive monitoring method is available at present to determine the real-time evaluation of automatic production quality control for friction welding machine. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the initial cumulative counts of acoustic emission(AE) occurring during plastic deformation period of the welding and the tensile strength of the welded joints as well as the various welding variables, as a new approach which attempts finally to develop an on-line (or real-time) quality monitoring system and a program for the process of real-time friction welding quality evaluation by initial AE cumulative counts. As one of the important results, it was well confirmed that the initial AE cumulative counts were quantitatively and cubically correlated with reliability of 95% confidence level to the joint strength of the welds, bar-to-bar (SCM4 to SUM31, SCM4 to SUM24L) and that an AE technique using initial AE counts can be reliably applied to real-time strength evaluation of the welded joints, and that such a program of the system was well developed resulting in practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro-structural defects.