| 摘要 |
PURPOSE:To elevate the spalling of a slag and to improve the man/hour of a work by changing the welding method of the large bore end part of a mild steel base material from a submerge arc welding method to CO2 semi-automatic welding method. CONSTITUTION:A roll mild steel base material 11 is welded upto its bank part with making the angle of the positioner for rotation supporting it constant and with performing a multilayer build-up welding with adding a flux to a wear resistant hardening build-up welding material by a submerge arc welding method. The large bore end part of the base material 11 is in succession subjected to a hardening build-up welding by a CO2 semi-automatic arc welding method with rotating the base material 11 upto reaching the bank part of the base material 11 with using the wire containing a flux for CO2 arc welding and the build-up welding part 13 of the large bore end part is obtd. A dressed build-up welding part 14 is then obtd. so as to make the final finishing part of the base material 11 a plane face by the submerge arc welding method. A hardened build-up roll 15 is thus obtd. |
