Method for welding of end plug of control rod

A method for welding an end plug to an open end of a surface-coated tube to provide a control rod, comprising the steps of:

• (a) providing said surface-coated tube so as to include a tube body having said open end and a hard coating formed on an outer peripheral surface thereof so as to extend to said open end, and providing said end plug which includes a plug body formed of the same material as said tube body of said surface-coated tube and a hard coating provided thereon and formed of the same material as said hard coating of said surface-coated tube;
• (b) bringing said end plug into pressing abutment with said open end of said surface-coated tube;
• and
• (c) performing resistance welding to join said end plug with said open end of said surface-coated tube by applying electric current between said surface-coated tube and said end plug to heat the same while keeping said end plug in pressing abutment with said open end of said surface-coated tube.

A method for welding an end plug to an open end of a surface-coated tube to provide a control rod, comprising the steps of:

• (a) providing said surface-coated tube so as to include a tube body having said open end and a hard coating formed on an outer peripheral surface thereof so as to extend to said open end, and providing said end plug formed of the same material as said tube body of said surface-coated tube;
• (b) bringing a portion of said end plug into engagement with a portion of said tube body defining said open end of said surface-coated tube with said portion of said end plug engaging said portion of said tube body at a location on said open and of said surface-coated tube in spaced relationship with respect to said hard coating on said surface-coated tube;
• (c) performing resistance welding to join said end plug with said open end of said surface-coated tube by applying electric current between said surface-coated tube and said end plug to heat the same while keeping said end plug in pressing abutment with said open end of said surface-coated tube;
• (d) thereby forming a welded joint between said end plug and said surface-coated tube which is free of any said hard coating dissolved therein.