HEAT TREATMENT APPARATUS FOR BUILD-UP WELDED ROLL EXCELLENT IN HEAT CRACKING RESISTANCE

摘要

PROBLEM TO BE SOLVED: To enhance a quench-hardening cooling speed and to improve the heat-cracking resistance by heating a part of a build-up welded roll in circle and cooling the roll surface over the whole heating completed part from the rear end of the heated portion while moving the heating part. SOLUTION: For preventing bending, etc., of the build-up welded roll 1, the roll is connected to a roll rotating mechanism 2 and supported with roll supporting tires 3. For heating near the surface layer of the roll, an annular induction heating coil 3 is used as a heating ring for heating in the circular state and the heating coil is fitted to a heating coil shifting mechanism 5 with a ball screw mechanism and the shifting speed is changed according to the heating width. In this mechanism, a part of the roll 1 is heated in the circular state with the induction heating coil, and the heating portion is continuously shifted in the roll axial direction at the fixed speed. Just after shifting, cooling liquid 6 is atomize-supplied on the roll surface from a cooling liquid atomizing nozzle 7 over the whole body of the heating completed part from the rear end of the heating part to execute the hardening treatment.