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:
Aug. 04, 1981
Filed:
Aug. 29, 1979
Mitsukuni Yamagata, Chiba, JP;
Keiichiro Takitani, Nagoya, JP;
Sadao Hasuno, Chita, JP;
Kuniaki Motoda, Chiba, JP;
Kawasaki Steel Corporation, Hyogo, JP;
Abstract
The method of producing steel pipe material for an oil well is characterized in that, as for the chemical composition of steel, B contained steel is adopted avoiding the addition of Ti which increases the values of non-metallic inclusions to decrease machinability, the value of N is limited to not more than 0.003% to be decreased in content of nitrides, coarse crystal grains due to the decreased content of N are prevented through austenizing of steel under rapid heating, so that such a steel pipe material for an oil well can be obtained that which has resistance to sulfide stress corrosion in addition to satisfactory strength and machinability.