Patent ID: 6689231
Filing Date: 2004-02-10
Classification: C21D,C22C,F16L

Abstract:
A method of using an alloy, the alloy having a composition comprising, in wt. %: C maximum 0.05%, Si maximum 0.8%, Mn 0.30-1.5%, Cr 28.0-30.0%, Ni 5.80-7.40%, Mo 2.00-2.50%, N 0.30-0.40%, Cu maximum 1.0%, W maximum 2.0%, S maximum 0.010%, 30-70% ferrite and the balance austenite, and an average proof strength of at least approximately 890 MPa, the method comprising forming a tube from the alloy, and incorporating the tube into an umbilical for a deep sea oil exploration control unit.