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. 23, 1986
Filed:
Apr. 24, 1985
Ingo von Hagen, Krefeld, DE;
Hans-Georg Hillenbrand, Dusseldorf, DE;
Rolf K Popperling, Mulheim, DE;
Mannesmann AG, Duesseldorf, DE;
Abstract
A ferritic perlite steel is used for pipes and tubing to be highly resistant against stress corrosion cracking when exposed to H.sub.2 S, and having following alloying range, all percentages by weight: from 0.3 to 0.45 C, from 1.4 to 1.8 Mn, from 0.2 to 0.5 Si, from 0.2 to 0.5 Cr, from 0.04 to 0.1 V, up to 0.06 Nb, .ltoreq.0.003 S, the remainder being iron whereby the combined Niobium and Vandium content must obey the rule that the sum of the V content plus twice the Nb content must not be not less than 0.1%; tubing is made by hot working followed by cooling in air from the final temperature attained during hot working, so that a texture and grain size in accordance with ASTM finer than 8 obtains; the tubing has strength value of 552 N/mm.sup.2 .ltoreq.0.2% of rupture elongation limit .ltoreq.655 N/mm.sup.2 and a tensile strength exceeding 655 N/mm.sup.2.