In the case of electrodes of Pressend, Stabilend etc. and also Fleet weld No 5, Sibaura E (used in normal polarity), it is the normal form of the material transference that- the electrode metal passes through the arc space in the small particle form, but when the arc length is short, the mechanical contact between the electrode and the base metal may occurs sometimes. This mechanical contact however, is only the accompaning phenomena in the particle forming process, and is not the indispensable phenomena for the material transference as in the case of bare or thin coated electrodes. So the physical meaning of the short circuit or bridging over is radically different in these two types of the electrodes.
The above mentioned difference is also confirmed by the oscillographic study of the short circuit. In the case of bare electrode, probability curve which shows the relation between the durations of the short circuits and the numbers of their occurrences in a unit time indicates the existence of the two distinct types of the short circuit as shown in a previous paper, but in the case of Stabilend, for example, there is no tendency of this existence of the two types. See Fig. 43, 44.
It is often said that the short circuit occours frequently in the bare electrode and so the mass transfered per short circuit (often expressed in the term of per drop) is small, suggesting the reason of greater inclusion of nitrogen compared with coated electrodes, but it is necessary to consider the bridge over and particle form transference in the case of coated electrodes.
In the case of bare electrode, the metal transfers only during the short circuit, but this short circuit occurs as the result of the violent up and down motion of the molten part of the electrode tip and the base metal due to the included gas or vapour, and the number of short circuit ocourrenee is too much and this is the reason why the men amount transfered per short circuit is very small.
Some other consideration$ are described in the main report.
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