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.

Date of Patent:
Feb. 05, 1991

Filed:

Sep. 07, 1989
Applicant:
Inventors:

Fumio Obata, Kitakyusyu, JP;

Hideaki Nagayoshi, Kitakyusyu, JP;

Eiji Nakano, Saikawa, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C22C / ; C21D / ;
U.S. Cl.
CPC ...
148-3 ; 148321 ; 148139 ;
Abstract

A thin high-strength article of spheroidal graphite cast iron having graphite particles dispersed in a ferrite matrix containing 10% or less of pearlite, characterized in that there are substantially no fine gaps between the graphite particles and the ferrite matrix. It is produced by pouring a melt having a spheroidal graphite cast iron composition into a casting mold; removing the casting mold by shake-out, while substantially the entire portion of the resulting cast iron product is still at a temperature of its A.sub.3 transformation point or higher; immediately introducing the cast iron product into a uniform temperature zone of a continuous furnace kept at a temperature of the A.sub.3 transformation point or higher, where the cast iron product is held for 30 minutes or less to decompose cementite contained in the matrix; and transferring the cast iron product into a cooling zone of the continuous furnace to cool the cast iron product at such a cooling speed as to achieve the ferritization of the matrix.


Find Patent Forward Citations

Loading…