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:
Feb. 16, 1993
Filed:
Apr. 02, 1992
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
A spheroidal graphite cast iron article having a thin portion and a thick portion, the number of spheroidal graphite particles having a diameter of 2 .mu.m or more being 600 /mm.sup.2 or more and less than 2000 /mm.sup.2 in the thin portion and 130 /mm.sup.2 or more and less than 600 /mm.sup.2 in the thick portion, and spheroidization percentage being 70% or more in the thick portion, is produced by a method comprising the steps of: (a) preparing an iron-base alloy melt having a composition consisting essentially by weight of 3.0-4.0% of C, 0.8-1.7% of Si, 1.0% or less of Mn, 0.2% or less of P, 0.01-0.2% of S, the balance being substantially Fe and inevitable impurities; (b) desulfurizing the iron-base alloy melt to control the sulfur content of the melt to less that 0.01% by weight; (c) adding a sulfur-containing material to the melt in such an amount that the sulfur content of the melt becomes 0.011-0.03% by weight; and (d) adding an Mg-containing material and a lanthanide element to the melt to conduct a spheroidizing treatment.