Abstract
In this research, a single bead was deposited on each constructional special, steel plate and the hardness distribution on the section perpendicular to the bead line was surveyed. And the following results were obtained.
(1) The maximum hardness in the heat-affected zone of base metal, which is adjacent to the weld, becomes higher with increase of thickness of the base metal plate.
(2) The position of a curve showing the relation between the maximum hardness in the heat-affected zone and the thickness of the base plats is variable with chemical compositions of the metal. Though equally called constructional special steel, there is often a wide difference in carbon content, and owing to this fact a remarkable difference is often confirmed among their maximum hardnesses of the heat-affected zone.
(3) The larger the diameter of electrodes used for welding is, the lower the maximum hardness of the heat-affected zone is. But in regard to alloy steels containing high carbon or special steels having large quenchhardenability, such tendency is hard to be found.
And on these facts, the authors tried to make simple considerations.
