Patent ID: 6518534
Filing Date: 2003-02-11
Classification: B23K,C23C

Abstract:
An apparatus for forming a weld and for forming a chromium oxide passivated film on the welded area, the apparatus comprising:a source of process gas, said process gas comprising argon combined with oxygen at a concentration of approximately 30-100 ppm and with a total impurity content, of moisture and total hydrocarbon content, of less than approximately 1 ppb; a source of welding gas, said welding gas comprising argon combined with approximately 5-10% hydrogen with a total impurity content, of moisture, oxygen and total hydrocarbon content, of less than approximately 1 ppm; a source of shielding gas, said shielding gas comprising argon with a total impurity content, of moisture, oxygen and total hydrocarbon content, of less than approximately 1 ppm; a welding means for applying heat to the area to be welded; and a means for flowing said shielding gas over an area to be welded prior to a welding step, for flowing said welding gas over the area to be welded during the welding step wherein said welding means applies heat to the area to be welded to form a weld, and for flowing said process gas over the welded area subsequent to the welding step to form a chromium oxide passivated film on the welded area.