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:
Apr. 02, 2024
Filed:
Apr. 14, 2020
Applicant:
Kabushiki Kaisha Riken, Tokyo, JP;
Inventor:
Tomoyuki Tobita, Tokyo, JP;
Assignee:
KABUSHIKI KAISHA RIKEN, Chiyoda-ku, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C21D 5/00 (2006.01); C21C 1/10 (2006.01); C22C 33/04 (2006.01); C22C 37/04 (2006.01);
U.S. Cl.
CPC ...
C21D 5/00 (2013.01); C21C 1/10 (2013.01); C22C 33/04 (2013.01); C22C 37/04 (2013.01); C21D 2211/009 (2013.01);
Abstract
A spheroidal graphite cast iron having a chemical composition of: C: 3.0% to 4.0%, Si: 2.0% to 2.4%, Cu: 0.20% to 0.50%, Mn: 0.15% to 0.35%, S: 0.005% to 0.030%, Mg: 0.03% to 0.06%, each by mass, and the balance being Fe and inevitable impurities, where Mn and Cu are contained at 0.45% to 0.75% in total; and a structure in which a ferrite layer encloses spheroidal graphite crystallized out in a matrix of pearlite. Part of the pearlite is extended from the matrix side to the spheroidal graphite side to divide the ferrite layer at one or more areas.