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. 25, 1991
Filed:
Aug. 03, 1989
Helmut Pohl, Neunkirchen, AT;
Schoeller-Bleckmann Gesellschaft m.b.H., Ternitz, AT;
Abstract
In a process for the production of tubular bodies that are resistant to stress corrosion cracking, in particular non-magnetizable drill stems and rod sections of austenitic steels, after solution treatment, quenching, and after deformation at a temperature of under 500.degree. C., in order to increase the mechanical properties of the material, and after processing and incorporation of a drilling, the body is heated to a temperature of 220.degree. to 600.degree. C., at least to temperature equalization with a temperature differential of at most 10.degree. C. in the walls of the body. The body is then maintained for at most a time t in minutes at a temperature T in degrees Celsius in accordance with the expression