As the carbon-content increases the welding power naturally decreases rapidly, because of the rapid fall of the " solidus curve at which solidification is complete (Aa of fig.
The reason for its birth, of course, is that the solubility of carbon in austenite progressively decreases as the temperature falls, from about 2.2% at 1130° (a), to 0.90% at 690° (Ar 1), as shown by the line aS, with the consequence that the austenite keeps rejecting in the form of this pro-eutectoid cementite all carbon in excess of its saturation-point for the existing temperature.
The electromotive force is practically constant no matter what the velocity of the disks, but according to some observers the internal resistance decreases as the velocity increases.
In this particular case the solubility decreases with rise of temperature.
The mean annual temperature decreases to the north-westward on the Alleghany plateau, but on the Erie plain, in the extreme north-west, Lake Erie exerts its moderating influence, the mean temperature rises, and extremes shorten.