Si-killed steel wire rod and spring

Patent metadata

Field	Value
Publication number	US-9290822-B2
Application number	US-51917907-A
Country	US
Kind code	B2
Filing date	Dec 3, 2007
Priority date	Dec 28, 2006
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A Si-killed steel wire rod for obtaining a spring excellent in fatigue properties and a spring excellent in fatigue properties obtained from such steel wire rod are provided. In the Si-killed steel wire rod of the present invention, oxide-based inclusions present in the wire rod contain SiO 2 : 30-90%, Al 2 O 3 : 2-35%, MgO: 35% or below (not inclusive of 0%), CaO: 50% or below (not inclusive of 0%), MnO: 20% or below (not inclusive of 0%) and BaO: 0.2-20% respectively, and total content of (CaO+MgO) is 3% or above.

First claim

The invention claimed is:

1. A Si-killed steel wire rod, comprising: 0.03-30 mass ppm of Ba, 1-30 mass ppm of Al, and 2-4 mass % of Si, and a total of Mg and Ca in a range of 0.5-30 mass ppm, wherein the balance is Fe and inevitable impurities.

2. A Si-killed steel wire rod comprising:
0.04-30 mass ppm of the total of Ba and Sr provided that Sr≦20 mass ppm,
1-30 mass ppm of Al, an
2-4 mass % of Si, and
a total of Mg and Ca is in a range of 0.5-30 mass ppm.

3. The Si-killed steel wire rod according to claim 1 , comprising 0.03-20 ppm of Li.

4. The Si-killed steel wire rod according to claim 1 , composed of steel comprising from greater than 0% to 1.2% of C, and 0.1-2.0% of Mn.

5. The Si-killed steel wire rod according to claim 4 , further comprising at least one element selected from the group consisting of 0.5-3% of Cr, 0-0.5% of Ni, 0-0.5% of V, 0-0.1% of Nb, 0-0.5% of Mo, 0-0.5% of W, 0-0.1% of Cu, 0-0.1% of Ti, 0-0.5% of Co, and from 0 to about 0.05% of a rare earth element.

6. A spring obtained from the Si-killed steel wire rod according to claim 1 .

7. A Si-killed steel wire rod, consisting essentially of: 0.03-30 mass ppm of Ba, 1-30 mass ppm of Al, and 2-4 mass % of Si, a total of Mg and Ca in a range of 0.5-30 mass ppm, greater than 0% to 1.2% of C, and 0.1-2.0% of Mn, wherein the balance is Fe and inevitable impurities.

8. The Si-killed steel wire rod according to claim 7 , further comprising 0.03-20 ppm of Li.

9. The Si-killed steel wire rod according to claim 7 , further comprising at least one element selected from the group consisting of 0.5-3% of Cr, 0-0.5% of Ni, 0-0.5% of V, 0-0.1% of Nb, 0-0.5% of Mo, 0-0.5% of W, 0-0.1% of Cu, 0-0.1% of Ti, 0-0.5% of Co, and from 0 to about 0.05% of a rare earth element.

Assignees

• Sugimura Tomoko
• Sakamoto Koichi
• Kobe Steel Ltd

Inventors

• Sugimura Tomoko
• Sakamoto Koichi

Classifications

• C22C38/30

  with cobalt · CPC title

• C22C38/08

  containing nickel {(C22C38/105 takes precedence)} · CPC title

• C21C7/04 Primary

  Removing impurities by adding a treating agent · CPC title

• C21D9/02

  for springs · CPC title

• C22C38/24

  with vanadium · CPC title