To provide a gas sensor capable of suppressing corrosion on a weld zone between a metal outer cylinder and a main metal fitting, and measuring an accurate gas concentration over a long period, which is a gas sensor formed by fixing a distal end of the metal outer cylinder on the periphery of a rear end of the main metal fitting by the weld zone by whole circumferential laser welding.
This gas sensor 100 includes: a gas detection element 110 extended in the axial direction, whose distal end side is exposed to gas to be measured; the cylindrical main metal fitting 120 for holding the gas detection element 110 so as to be projected from its own distal end side; and a cylindrical metal outer cylinder 200 whose distal end 200s is fixed by the whole circumferential laser welding on the periphery of the rear end 120k of the main metal fitting 120. The metal fitting 120 includes Fe as a main component, 0.02 to 0.15 mass% of C, 11.5 to 18.0 mass% of Cr, and Nb as much as double or more to C in the mass.
HIRASAWA MAKOTO
MATSUBARA YOSHIAKI
| JP2004258049A | 2004-09-16 | |||
| JPS59222561A | 1984-12-14 | |||
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