Submerged arc welding process with high productivity has been one of the widely-used surfacing methods for recycling worn components or fabricating bimetal. Surfacing with a lay-down plate electrode is a new variation of submerged arc surfacing, in which metal is deposited on the surface of a workpiece by arc heat between the workpiece and a plate laid down on it.
Both direct and alternate current can be used as welding power source. Surfacing with a lay-down plate shows the possibility of reducing the cost for restoring worn components like large-scale straight teeth gears with large module, and of improving the productivity and quality of surfacing.
Temperature distribution resulted by spontaneous movement of electric arc has a big effect on the stability and quality of surfacing with a lay-down plate. However, to the best of our knowledge, there have not been many discussions regarding the spontaneous movement of electric arc and the analysis of temperature field during surfacing with a lay-down plate electrode.
In order to make an optimal surfacing process condition, Pak Sang Yun, a researcher at the Faculty of Materials Science and Technology, has modeled the spontaneous movement orbit of arc during surfacing with a lay-down plate electrode and investigated its temperature distribution by ANSYS.
He has drawn the following conclusions.
First, the periodic and stable movement of electric arc, which is self-controlled in the channel during surfacing, results from periodic variation of forces acting on electric arc.
Second, the dimension and shape of the weld pool varies with time, but the boundary of solidus temperature is constant regardless of time. Thus, the temperature field remains in quasi-stationary state during surfacing with a lay-down plate electrode.
Third, the distribution of quasi-stationary temperature field depends on build-up technical conditions and the width of plate electrodes.
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