L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des

L'air Liquide

Henri Chevrel

Jean-Marie Friedt

Alain Boireau

Hideki Takagi

Eiichi Ozawa

A Nimal Liyanage

Taeko Hattori

A process to avoid or limit corrosion at the junction of two piping comprising devices welded together, said piping comprising devices being adapted to flow corrosive gases through them, said process comprising the steps of:

Process for assembling piping or components by TIG welding

Avoidance of the corrosion initiation sites consisting of Mn particles deposited on the TiG welded inner tube surface is achieved through suppression of emission of manganese fumes by addition of a protective non corrosive metallic layer. The latter melts during the welding and arises in a non-corrosive internal metallic coating of the welded zone.

Pipe welding process using a metallic insert for improved corrosion

A process for welding stainless steel tubing in the presence of an inert gas comprising a silicon base gas, in particular silane SiH.sub.4. During the welding operation, a suitable quantity of silicon is deposited by chemical vapor deposition at the weld joint to significantly improve the corrosion resistance of the weld.

Corrosion resistant welding of stainless steel

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Tsukuba, Japan

Henri Chevrel