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:
Oct. 09, 1979
Filed:
Jan. 27, 1978
Hiroyuki Kaito, Takarazuka, JP;
Takashi Ohtani, Ashiya, JP;
Shoji Iwaoka, Ashiya, JP;
Yukio Oguchi, Chiba, JP;
Shuya Yano, Chiba, JP;
Akio Ejima, Chiba, JP;
Kawasaki Steel Corporation, Kobe, JP;
Abstract
High chromium steels having extremely low carbon and nitrogen contents are produced by blowing more than 15 up to 40 Nl/min per ton of molten steel of an inert gas into a high chromium steel containing 0.8 to 2.5% of C and 10 to 35% of Cr in a ladle under a reduced pressure from bottom of a ladle and concurrently blowing oxygen gas to the molten steel surface to form 1 to 100 kg per ton of the molten steel of a slag containing not less than 20% of SiO.sub.2 and not more than 25% of Cr.sub.2 O.sub.3 at the end of oxygen blowing, terminating the oxygen blowing when the carbon concentration in the molten steel becomes not more than 0.020%, and subsequently blowing 6 to 40 Nl/min per ton of molten steel of an inert gas under a high vacuum of not more than 10 torr.