Method of brazing corrosion resistant nickel-based thin-walled tubing to stainless steel base members

The method of brazing corrosion resistant, nickel-based, thin-walled tubing having a wall thickness of less than about 12 mils and which includes substantial proportions of nickel, chromium and molybdenum with an iron content limited to a maximum of 7 percent by weight to a stainless steel base member without introducing stress corrosion cracks in the tubing and also avoiding carbon precipitation in the brazed corrosion resistant tubing, which method comprises:

• retaining said tubing and said base member to be brazed in adjacent positions desired for the brazed product and positioning a filler metal principally comprising gold as a major constituent and nickel as a minor constituent proximate the adjacent portion of said tubing and said base member;
• evenly heating said tubing and said base member and said filler metal under vacuum conditions to a temperature of at least about 1900.degree. F. for a sufficient period of time not exceeding about 8 minutes to avoid excessive reaction between said filler metal and said parts being brazed and to allow any carbide precipitate formed during heating to redissolve and to permit full uniform flow of said filler metal between said tubing and said base member;
• and rapidly quenching said retained and heated members in a gaseous atmosphere which is non-reactive with respect to said retained and heated members to a temperature of less than about 1400.degree. F. to avoid carbide precipitation in said tubing.