Invention Grant
- Patent Title: Spring steel wire excellent in fatigue characteristic and wire drawability
- Patent Title (中): 弹簧钢丝疲劳特性和拉丝性优异
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Application No.: US12444001Application Date: 2007-10-30
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Publication No.: US08192562B2Publication Date: 2012-06-05
- Inventor: Nao Yoshihara
- Applicant: Nao Yoshihara
- Applicant Address: JP Kobe-shi
- Assignee: Kobe Steel, Ltd.
- Current Assignee: Kobe Steel, Ltd.
- Current Assignee Address: JP Kobe-shi
- Agency: Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2006-296993 20061031
- International Application: PCT/JP2007/071113 WO 20071030
- International Announcement: WO2008/053884 WO 20080508
- Main IPC: C22C38/00
- IPC: C22C38/00 ; C22C38/28 ; C22C38/32

Abstract:
An object of the preset invention is to provide a spring steel wire that: shows excellent wire drawability not only when it is used as a spring steel wire for cold-winding formed into a steel spring by applying quenching and tempering treatment after wiredrawing but also when it is used as a spring steel wire for cold-winding formed into a steel spring as it is wiredrawn; and secures a spring having an excellent fatigue characteristic after the spring steel wire is formed into the spring. The spring steel wire according to the present invention is a spring steel wire excellent in fatigue characteristic and wire drawability, wherein: the contents of C, Si, Mn, Cr, Ti, B, and other elements are specified; the contents (mass %) of B, Ti, and N satisfy the expression (1) below; the amount of solid solute B is in the range of 0.0005% to 0.0040%; the remainder in the spring steel wire is composed of Fe and unavoidable impurities; and the solid solute B concentrates at the grain boundaries of pearlite nodules, 0.03≦B/(Ti/3.43−N)≦5.0 (1).
Public/Granted literature
- US20100034691A1 SPRING STEEL WIRE EXCELLENT IN FATIGUE CHARACTERISTIC AND WIRE DRAWABILITY Public/Granted day:2010-02-11
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