Lightweight and excellent ductile bead wire, method for producing the same and lightweight tire

• US 8,647,450 B2
• Filed: 02/22/2007
• Issued: 02/11/2014
• Est. Priority Date: 04/11/2006
• Status: Expired due to Fees

• Current Assignee: Bridgestone Corporation
• Original Assignee: Bridgestone Corporation
• Inventors: Aoike, Yukio, Kikuchi, Masami, Yokoi, Takashi
• Primary Examiner(s): King, Roy
• Assistant Examiner(s): KIECHLE, CAITLIN ANNE
• Application Number:
  US12/296,597
• Publication Number:
  US 20090277558A1
• Time in Patent Office: 2,546 Days
• Field of Search: 148/329, 148/333, 148/337, 148/598, 420/72, 420/74, 420/77, 420/79, 152/540
• US Class Current: 148/329
• CPC Class Codes: B29D 2030/487 Forming devices for manufacturing the beads
• CPC Class Codes: B29D 30/48 Bead-rings or bead-cores from wire B21F37/00; Treatment thereof prior to building the tyre
• CPC Class Codes: B60C 15/04 Bead cores
• CPC Class Codes: C21D 8/06 during manufacturing of rods or wires
• CPC Class Codes: C21D 9/52 for wires; for strips ; for rods of unlimited length
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/38 with more than 1.5% by weight of manganese
• CPC Class Codes: D07B 1/066 the wires being made from special alloy or special steel composition
• CPC Class Codes: D07B 2201/2009 characterised by the materials used
• CPC Class Codes: D07B 2205/3032 Austenite
• CPC Class Codes: D07B 2205/3046 characterised by the carbon content
• CPC Class Codes: D07B 2205/306 Aluminium (Al)
• CPC Class Codes: D07B 2501/2046 Tire cords
• CPC Class Codes: D07B 2801/10 Smallest filamentary entity of a rope or strand, i.e. wire, filament, fiber or yarn

Abstract

A bead wire has a composition of Mn: 5-35 at % and Al: 5-20 at % and the remainder being Fe and inevitable impurities, in which a steel structure is an austenite single-phase structure, and achieves weight reduction and high ductility without reducing strength.

Claims

1. A lightweight and excellent ductile bead wire for a bead core in a tire having a composition of

Mn:

5-35 at % and

Al;

14-20 at %,

and the remainder being Fe and inevitable impurities, in which a steel structure is an austenite single-phase structure.

3. A lightweight and excellent ductile bead wire for a bead core in a tire according to claim 1, wherein the composition further contains Cr:

1-7 at % as an additional component.

4. A method for producing a lightweight and excellent ductile bead wire for a bead core in a tire, which comprises rolling a steel ingot having a composition as claimed in claim 1 to form a wire rod, cooling the wire rod, heating to a temperature of 900-1100°

C., quenching to render a steel structure into an austenite single-phase structure, drawing and then subjecting to a bluing treatment.

5. A lightweight tire comprising a bead wire for a bead core in a tire as claimed in claim 1.

2. A lightweight and excellent ductile bead wire for a bead core in a tire having a composition of

C:

0.1-1.5 at %,

Mn;

5-35 at % and

Al;

14-20 at %,

and the remainder being Fe and an inevitable impurities, in which a steel structure is an austenite single-phase structure and fine carbides are included in the austenite single-phase structure.