DIRECT RESISTANCE HEATING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a direct resistance heating device capable of: uniformly heat-treating a metal shaft material by uniformly press-contacting a heat dissipation block to an outer peripheral surface on each end side of the metal shaft material in an axial direction to dissipate heat; and uniformly heat-treating the metal shaft material by uniformly press-contacting the heat dissipation block to the outer peripheral surface on each end side of the metal shaft material in the axial direction to stably dissipate heat even when thermal expansion due to direct resistance heating enlarges the diameter of the metal shaft material or elongates the metal shaft material in the axial direction.SOLUTION: A direct resistance heating device can move each heat dissipation block (75 and 77) following inclination of the shaft center of a metal shaft material (5) held by a pair of electrode (7 and 9) in a direction coincident with the axis and in a direction orthogonal to the axis, and contact each contact part (75a and 77a) rockable in a horizontal direction to the outer peripheral surface of the metal shaft material (5) to dissipate heat from the metal shaft material (5) subjected to direct resistance heating.