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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Welding and Joining
Journal Basic Information
Journal DOI :
The Korean Welding and Joining Society
Editor in Chief :
Volume & Issues
Volume 8, Issue 4 - Dec 1990
Volume 8, Issue 3 - Sep 1990
Volume 8, Issue 2 - Jun 1990
Volume 8, Issue 1 - Mar 1990
Selecting the target year
Disbonding in aspect of the behavior of hydrogen embrittlement
Journal of Welding and Joining, volume 8, issue 1, 1990, Pages 2~11
Ultrasonic testing technique for defects of weldment
Journal of Welding and Joining, volume 8, issue 1, 1990, Pages 12~22
A study on seam tracking with an arc signal in GMA welding process with mixed gas
Journal of Welding and Joining, volume 8, issue 1, 1990, Pages 23~30
The robotic welding has been adapted positively in many welding shops forthe purpose of improving the welding efficiency and liberating operators from the severe working atmosphere. But for a large-size structure with thick plates like ship-building and every kind of plants manufacturing, the application of the arc welding robots is not established yet. The reason is assumed that the conventional arc welding robots are not adaptive for multi-pass welding of thick plates whose grooves are not so accurate. As one solution to this problem, a guidance system which uses the welding arc itself as a sensor is largely used. In this study the velocity controller which changes the tip to workpiece distance for regulating the weld proposed. The proportional and integral gain of velocity controller were determined by using the computer simulation of the control system, and the simulation results compared with the experimental ones. It was revealed that the developed control system using the arc sensor principle has a good capability of tracking the weld joint, although some more studies will be needed to refine the model of arc current.
Real-time estimation of arc stability in GMAW process
Journal of Welding and Joining, volume 8, issue 1, 1990, Pages 31~42
Arc must be stable during welding first of all other factors for obtaining sound weldment, especially in the automation of welding process. Arc stability is somewhat sophisticated phenomenon which is not clearly defined yet. In consumable electrode welding, the voltage and current variation due to metal transfer enables to assess arc stability. Recently, statistical analyses of the voltage and current waveform factors are performed to assess the degress of arc stability which is assessed and controlled by operator's own experience by now. But, considering the increasing need and the trend of automation of welding process, it is necessary to monitor arc stability in real-time. In this sutdy, the modified stability index composed of two voltage and current wvaeform factors (arc time and short circuit time) reduced from four factors (arc time, short circuit time, average arc current and average short circuit current) in Mita's index by the welding electrical circuit modeling is proposed and verified by experiments to be well estimating arc stability in the static sense. Also, the recursive calculation form estimating present arc stability in the dynamic sense is developed for real-time estimation. The results of applying the recursive index during welding show good estimation of arc stability in real-time. Therefore, the results of this study offers the mean for real-time control arc stability.
A study on welding structure and thermal behavior in friction welding of austenitic stainless steel
Journal of Welding and Joining, volume 8, issue 1, 1990, Pages 43~53
The transient temperature distribution in the continuous friction welding 304 stainless steel bars is investigated by experimental and analytical methods. It is calculated by F.D.M. (finite difference method). The heating pressure, the rotational speed and friction coefficient obtained from experiment are used to determine the heat input at the contacting surface. Thermal properties of the workpiece are the function of temperature. The calculated temperature is well coincided with the measured value. The grain size at weld interface is extremely small due to the severe plastic deformation at high temperature, and result of this refined zone reveals higher hardness value. Because the HAZ is very narror about 2-3 mm, welding defects do not occure.
고탄소계 Cr-Ti 합금강 레일재의 용접성에 관한 기초연구
Journal of Welding and Joining, volume 8, issue 1, 1990, Pages 54~61
A pilot production is made to the high carbon Cr-Ti alloy rail steels with slight quantity of Cr & Ti added to the eutectoid carbon steel. As a part of weldability of these alloy steels, SH-CCT diagram for welding is first applied to the high carbon Cr-ti alloy rail steel with 0.1wt% Ti. The microstructure, which will be appeared at the HAZ of Enclosed-arc welding of this alloy rail seel, is a single phase of pearlite. As a result of this, it shows that the welding condition of Enclosed-arc welding applied to this alloy rail steel is a good condition.
Simulation of heat flow for rectangular electrodes
Journal of Welding and Joining, volume 8, issue 1, 1990, Pages 62~69
Being focused on the recent studies that the fatigue strength of resistance spot weldmentes can be improved by using ellipsoidal weld nuggets, the voltage and temperature distribution in resistance spot weldments were simulated for the various rectangular electrodes which had the different aspect ratio of the contact area. Because the electrode shape was not axi-symmetric, the solution domain for simulation should be three dimensional. A series of experiments were carred out to verify the analytically obtained temperature distribution in the weldment. From the calculational and experimental results, it could be revealed that the nugget took the form of ellipsoid, while both results showed a considerable discrepancy for the high aspect ratio.