Method for manufacturing mill roll, mill roll and manufacturing apparatus of mill roll

A manufacturing apparatus of a mill roll, the mill roll comprising:

• a roll barrel member having a hard tinkering hardfacing layer formed on an outer circumference of a columnar core material consisting of chromium-molybdenum steel or carbon steel;
• and
• shaft materials consisting of chromium-molybdenum steel and being singly provided on both sides in an axial direction of the core material, wherein
• diameters of joining end portions of the shaft materials are made smaller than a diameter of the core material,
• the manufacturing apparatus of a mill roll comprising:
• a first holding means for holding the roll barrel member horizontally or perpendicularly;
• a second holding means for holding the shaft materials, the shaft materials being aligned with the axial center of the roll barrel member;
• a rotating means provided to the second holding means for rotating the shaft materials centering on the axial centers of the shaft materials;
• a pressing means provided to either the first holding means or the second holding means for pressing the core material and the shaft materials in the axial direction while joint surfaces of the core material and the shaft materials are facing each other;
• and
• a preheating means for preheating the joining end portions of both the roll barrel member and the shaft materials.