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:
Mar. 19, 1985
Filed:
Feb. 07, 1984
Applicant:
Inventors:
Assignee:
Nippon Steel Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
219100 ; 219104 ;
Abstract
A joint is made between two pieces of steel which have been preheated to a temperature To (.degree.C.) near their abutting surfaces by subjecting first to flashing and then to upsetting. When the ultimate flashing rate is V (mm/sec.), a current whose density I (A/mm.sup.2) is not lower than ##EQU1## is passed during the upsetting process to melt the abutting surfaces. With a mean upsetting rate of not lower than 50 mm/sec., only the molten metal is rapidly squeezed out from the abutting surfaces. Then, the upset current is cut off while applying a final upsetting force that is as low as under 5 kg/mm.sup.2.