On the Specific Deposited Heat of Welding Arc of Mild Steel

Abstract

The specific deposited heat or the specific Let transfer number, i e. the ratio of heat atsorbed by the base metal to the weight of deposited metal is measured for various kinds of electrodes, the core diameter being 4 mm The value varies from 12 to 25 Ka' per gram for ordinary arc length.
The value is independent of the current employed but increases as the arc length increases, because the melting speed of electrod metal is proportional to the current while the thermal efficiency is independent of the current, and the total heat input increases as the arc length increases (3), (4)
It will be higher for those electrodes and polarity which have lower melting speeds.
Fig. 3, 4 shov those relations.