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:
Jan. 21, 1992
Filed:
Jun. 20, 1990
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D / ;
U.S. Cl.
CPC ...
29130 ; 29 32 ;
Abstract
A compound roll for a metal rolling mill having both excellent resistance to a thermal shock crack and excellent wear resistance includes a core shaft made of low alloy steel and an outer layer consisting of high speed tool steel having a composition, by weight percent, essentially of 0.5 to 1.5% of C, 0.5 to 3.0% of Si, 1.5% or less of Mn, 2 to 7% of Cr, 1 to 5% of Mo, 0.5 to 2.0% of V, up to 2.0% of W and balance essentially Fe. The outer layer is formed on the outer surface of the core shaft by an electro-slag method. The outer layer is subjected to a water jet spray quenching and tempering at 300.degree. C. or higher, preferably 450.degree. C. to 550.degree. C.