METHOD FOR DECREASING RESIDUAL STRESS OF LARGE-SIZED HOLLOW ROLL AND REFRIGERANT GUIDE MEMBER USED IN THIS METHOD

摘要

PURPOSE:To economically decrease residual stresses by guiding a refrigerant to the inside surface of a roll by a the refrigerant guide members detained in the roll, controlling the amt. of the refrigerant heading toward the inside surface of the roll so as to be larger on the downstream side of the roll and thereby forcibly cooling the roll. CONSTITUTION:Plural annular bodies 7 having high rigidity for preventing the deformation of the roll at the time of a heat treatment are removable detained in the large-sized casting roll 1 to be cooled. The refrigerant guide members 8 for guiding a part of the refrigerant so as to diverge the same outward are provided in the annular bodies 7. The bar material 81 of the members 8 are so inclined that the downstream side of the refrigerant flow heads gradually outward, thus forming the guide surfaces 82 to guide the air flow toward the inside surface of the roll. A part of the supplied refrigerant comes into contact against the guide surfaces 82 of the members 8 and flows toward the downstream side while spreading toward the outside. The inside surface of the roll is thus effectively cooled. The amt. of the refrigerant heading toward the inside surface of the roll is increased more on the outlet side than on the refrigerant inlet side of the roll by the members 8, by which the increase of the refrigerant temp. toward the downstream is offset and the difference in the cooling rate between the inlet side and the outlet side is decreased.