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:
Dec. 08, 2015
Filed:
Nov. 02, 2011
Soon-tae Ahn, Busan, KR;
Soon-Tae Ahn, Busan, KR;
Samhwa Steel Co., Ltd., Pusan, KR;
Abstract
A method of manufacturing high strength steel wire for cold forging containing 0.15-0.40 wt % of C, less than 1.5 wt % of Si, 0.30-2.0 wt % of Mn, less than 0.03 wt % of P, and less than 0.03 wt % of S. After initial cold-drawing, the wire rod is heated in a series of high frequency induction heating devices over the Ac3 transformation point for 30-90 seconds. The wire rod is then rapidly cooled and tempered at a temperature of from 500° C. to the A1 transformation point for 30-90 seconds. The wire rod is then cooled to achieve a tensile strength of 1,100-1, 400 MPa. The wire rod is then cold-drawn at an area reduction rate in excess of 25% and up to 40% to yield a tensile strength of 1,200-1,600 MPa, with improved service life of the mold.