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:
Jun. 16, 1992
Filed:
Jun. 12, 1991
Ingo von Hagen, Krefeld, DE;
Gerd Heinz, Merrbusch-Strump, DE;
Rolf K Popperling, Mulheim, DE;
Hubertus Schlerkmann, Roetgen, DE;
Mannesmann Aktiengesellschaft, Dusseldorf, DE;
Abstract
A method of improving the resistance to H-induced stress-corrosion cracking of articles of low- to medium-alloy structural steels which come into contact with aqueous H.sub.2 S-containing fluids and which are manufactured by one of (i) hot rolling, with or without subsequent heat treatment, (ii) by TM-rolling, with or without accelerated cooling, and (iii) by cold rolling with subsequent heat treatment and which are then cold strained from 0% to less than 2%. In order to economically increase the resistance of articles of structural steel to H-induced stress-corrosion cracking, the articles are subjected to a final annealing for a period of at least two seconds at a temperature which is at least 540.degree. C. and the upper limit of which is as follows: In the case of hot rolled or TM-rolled or normalized articles, 30K below A.sub.C1 ; in the case of hardened and tempered articles, 30K below the tempering temperature last employed.