Long life welding electrode and its fixing structure, welding head, and welding method

A long-life welding electrode comprising:

• a base material;
• and
• at least one oxide selected from a group consisting of lanthana, yttria, and ceria.

A welding system comprising:

• a welding electrode having a tip section with a form like a curved surface;
• and
• a welding head for holding said electrode.

A fixing structure for fixing a welding electrode to a fixing base comprising:

• a fixing base having an inserting section, the welding electrode having a fixed section inserted into said inserting section;
• and
• thermally conductive material inserted into said inserting section to uniformly contact a peripheral surface of said fixed section of the welding electrode to the fixing base.

A fixing structure on a fixing base for a welding electrode, said structure comprising:

• said fixing base having several divided portions, the welding electrode held between the divided portions for fixing the welding electrode to the fixing base.

A welding method comprising the steps of:

• supplying one of (1) a mixed gas of argon and helium, (2) a mixed gas of helium and hydrogen, or (3) a mixed gas of argon, helium, and hydrogen;
• and
• welding in such supplied mixed gas environment.