• Journal of Ocean Engineering and Technology
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• v.13 no.3 s.33
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• pp.83-91
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• 1999

Taking a view of joining by welding the IN713C to SCM440 and SCM415 steel in production of turbochargers, the frictin welding process may be utilized as a new approach for joining them of other conventional welding processes. It is because the friction welding has more technical and technical and economic advantages than the other welding processes. As this welding process has the characteristics such as curtaliment of production time and materials and cost reduction, etc.. So, this paper deals with determining the preper friction welding condition and analyzing various mechanical properties of friction welded joints of the super heat resisting steel to alloy stee(IN713C to SCM440 and SCM415). And the in-process real-time weld quality evaluation technique by acoustic emission during friction welding of IN713C to SCM440 and SCM415 steels with higher confidence and relibility has been much required even though it might be the first trial approach for developing it. Then, this first study aimed to develop the optimization of dissimilar friction welding of heat resisting steels (INC713 to SCM440, SCM415) for turbine, considering on strength and toughness.

• Journal of Ocean Engineering and Technology
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• v.13 no.1 s.31
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• pp.88-93
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• 1999

This paper presents the experimental examinations and statistical quantitative analysis of the correlation between the cumulative counts of acoustic emission(AE) during plastic deformation periods of the welding and the tensile strength and other properties of the bar-to-bar welded joints of O.D. 16mm shaft(SM40C) as well as the various welding variables. And this is a new approach which attempts finally to develop real-time quality monitoring system for friction welding. The results lead to a practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro structural defects.

• Journal of Welding and Joining
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• v.31 no.1
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• pp.26-32
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• 2013

Recently, welding technology of nonferrous metals which were difficult to implement by arc welder has become available through digitalization of arc welding machine. Among them, the welding quality improvement of aluminum welding is very noticeable. These results increase the arc stability by controlling arc current and voltage waveform precisely, and control wire feed speed by synchronizing with arc current which the feed rate of filler wire is controlled by a precise motor control of servomotor and not by a simple constant speed feeding. Not only through the hardware digitalization of arc welding machine but also through advance of software of arc welding, it became possible to implement a certain level of welding quality by a simple operation. These led to CMT welding process implementation which requires low heat input than current arc welding and highly increased the applicability of the aluminum welding.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.721-728
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• 2006

This paper is concerned with development of digital assembly cell. Automotive industries, try to find out new welding technologies to replace the existing spot welding which is not appropriate anymore. Because of many advantages like good accessibility, welding quality and fast welding speed, laser welding seems the most appropriate solution for automobile manufactures. To apply this technology to welding of car body, experiments must be conducted according to material, geometry and layer in welding area. Based on the data of these experiments, the laser welding process and the quality of stitches are identified. And then, the comparison between the requirements of welding and the potential of equipments allows selecting the best equipments. By using the digital manufacturing, the configurations of laser welding cell are carried out. After all, the optimal laser welding cell is chosen by the evaluation of alternative cells with technical and organizational criteria.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.230-237
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• 2015

To improve productivity and improve the welding process, we have studied the automated system of the weld by applying a tandem welding. Then, the speed of the welding process is improved, production of industries is increasing. Productivity of the industrial sector has increased the application of tandem welding for automated system of welding. But quality assurance for the product take place welding defects in the welding process because the speed of the process is increased. Definitive research solutions an dit's actuality, however, there is insufficient. Accordingly, it is a situation that the performance of the weld to ensure quality of the weld is required urgently after the welding process. Comparing and analyzing the results of passing each experiment of the two-electrode welding and the welding electrode1, a study attempted to quality assurance of the welded joint portion.

• Journal of Welding and Joining
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• v.25 no.6
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• pp.64-70
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• 2007

Recently, several models to control weld quality, productivity and weld properties in arc welding process have been developed and applied. Also, the applied model to make effective use of the robotic GMA(Gas Metal Arc) welding process should be given a high degree of confidence in predicting the bead dimensions to accomplish the desired mechanical properties of the weldment. In this study, a development of the on-line learning neural network models that investigate interrelationships between welding parameters and bead width as well as apply for the on-line quality control system for the robotic GMA welding process has been carried out. The developed models showed an excellent predicted results comparing with the predicted ability using off-line learning neural network. Also, the system will extend to other welding process and the rule-based expert system which can be incorporated with integration of an optimized system for the robotic welding system.

• Journal of Welding and Joining
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• v.21 no.3
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• pp.40-45
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• 2003

The high-speed rotating arc process forms a flat bead surface with decreased penetration depth because the molten droplets are deflected by centrifugal force. Therefore the rotating arc welding for horizontal fillet welding increases the leg length with the increase of rotation frequency and prevents the deflection of weld bead and overlap. In this study, the relationship between the welding parameters and the weld bead shape - leg length and undercut - are investigated experimentally. Consequently, the weld quality could be improved by rotating arc welding, and sound weld bead was achieved when applied to horizontal fillet welding with 4mm gap by avoiding the undercut which is inevitable for the conventional GMA welding methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.189-194
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• 2007

Recently, as consumer's claim fur car safety is increased, quality inspection method fur welding zone is strengthened. Therefore, from the methods that depend on welding zone bead shape size of seat frame in macrography or passive examination, the quality control by whole recording inspection is required. In this study, the system that is measuring automatically if worker checks welding bead fur quality inspection of seat frame is developed using LabVIEW. If the quality standard for the bead width and length of welding zone is inputted, the system measures automatically whether welding zone is bead length or bead width. Measured data is preserved by points and quality recording of welding zone is stored. The car seat きme welding zone is applied and experimented. The results gave good influence o9 the quality control of work efficiency.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.105-111
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• 2016

In order to inspect the quality of spot welding, inefficient destructive test and NDT (non destructive testing) utilizing expensive foreign ultrasonic inspection are being conducted in the automobile production lines, but NDT will be difficult to be used in the domestic automobile production due to complexity of the waveform analysis and lack of mobility. In this paper, NDT system inspecting the quality of spot welding based on mobile network is proposed to complement drawbacks of the conventional inefficient destructive testing and NDT inspecting the quality of spot welding. Regardless of daily condition of NDT tester, the proposed NDT system can determine the quality of spot welding automatically and transmit the information of NDT quality to smart devices of field workers in real-time so that convenience of NDT and productivity of automobile production will be improved. Several specimens with a variety of welding quality was produced to evaluate the performance of the proposed mobile ultrasonic NDT system and the conventional foreign equipment, through this experiments, the proposed mobile ultrasonic NDT system indicate the superior properties compared to the conventional equipment in terms of convenience, productivity, and economic.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2581-2588
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• 2000

In previous studies, the dynamic resistance, which was calculated by the process variables measured at the electrode of the welding machine, and the electrode displacement were used for quality exa mination. However, in-process usage of such systems is not effective in systems that include a welding gun attached to a robot. In order to overcome such problems, we obtained and used the process variables from the welding machine timer. This would allow us to estimate real time in -process weld quality. For quality estimation, the features were extracted as factors from the primary dynamic resistance patterns, which were measured in t he welding machine timer. The relationship between the indexes and nugget size of the welds was observed through the regression analysis. Using the analyzed factors, a regression model that could estimate nugget diameter was developed. Two regression equations of the model were suggested depending on the factors, and it was showed that the model developed by stepwise method was effective one for weld quality estimation. The developed estimation model was in good linearity with the nugget diameter obtained through the experimentation.