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:
Mar. 23, 1993
Filed:
Apr. 01, 1992
Avesta Aktiebolag, Avesta, SE;
Abstract
A stainless steel having a two-phase structure of austenite and ferrite, the steel consisting essentially of in weight-% not more than 0.03% C, not more than 0.03% N, the total amount of C+N not being more than 0.05%, 1.5-2.5% Si, 0.5-2% Mn, not more than 0.03% P, not more than 0.010% S, 22-26% Cr, 8-11% Ni, 2-3% Mo, 0.35-0.55% Ti, % Cr+3.3.times.% Mo being at least 29.0, balance iron and impurities, said steel having been subjected to a heat treatment consisting of solution annealing in the temperature range 1100.degree.-1250.degree. C. and water quenching followed by aging in a temperature range 500.degree.-600.degree. C. for at least 30 min, wherein precipitates consisting essentially of Ni.sub.16 Ti.sub.6 Si.sub.7, so called G-phase, are precipitated in the form of particles evenly distibuted in the ferrite, said particles typically having a size of 10-50 .ANG., imparting the material an improved yield srength in the annealed and aged condition, said yield strength amounting to at least 800 MPa in combination with a Charpy V impact strength of at least 25 J, a critical pitting temperature (CPT) higher than about 50.degree. C. in 3% NaCl-solution at 200 mV SCE, and a pitting potential Ep in 0.1N-NaCl-solution, 80.degree. C., of at least about 300 mV SCE.