The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1991
Filed:
May. 18, 1990
Glen A Gibbs, Warren, MI (US);
Arnold T Johnson, Davisburg, MI (US);
ITT Corporation, New York, NY (US);
Abstract
A process for brazing non-ferritic steel surfaces such as nickel chromium or stainless steel to which a suitable brazing alloy such as copper has been mechanically attached which includes the steps of instantaneously elevating the surface of the stainless steel to a brazing temperature while maintaining the material in a humidified gaseous atmosphere consisting essentially of a non-reactive carrier gas and a reactive gas present in sufficient concentrations to achieve fluxing; maintaining the surface temperature of the steel for an interval sufficient to permit fusion between the selected metal and the non-ferritic steel surface; after metal fusion has been achieved, allowing the resulting fused metal material to cool to a first lowered temperature in a controlled non-oxidative atmosphere at a rate which retards the formation of fine-grained steel crystals in the metal; and after reaching a metallurgical transformation point, rapidly cooling the fused metal in a controlled atmosphere to a temperature below which the brazing metal is not reactive with oxygen. This process can be employed successfully in manufacturing unique, seamless double-walled tubing which is relatively flexible and highly corrosion resistant.