Steel for induction hardening roughly shaped material for induction hardening

Patent metadata

Field	Value
Publication number	US-9890446-B2
Application number	US-201514707429-A
Country	US
Kind code	B2
Filing date	May 8, 2015
Priority date	Mar 30, 2010
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A steel for an induction hardening including, by mass %, C: more than 0.75% to 1.20%, Si: 0.002 to 3.00%, Mn: 0.20 to 2.00%, S: 0.002 to 0.100%, Al: more than 0.050% to 3.00%. P: limited to 0.050% or less, N: limited to 0.0200% or less, O: limited to: 0.0030% or less, and the balance composing of iron and unavoidable impurities, wherein an Al content and a N content satisfy, by mass %, Al−(27/14)×N>0.050%.

First claim

The invention claimed is:

1. A steel for an induction hardening comprising, by mass %,
C: more than 0.75% to 1.20%,
Si: 0.002% to 3.00%,
Mn: 0.20% to 2.00%,
S: 0.002% to 0.100%,
Al: more than 0.050% to 3.00%,
P: limited to 0.050% or less,
N: limited to 0.0200% or less,
O: limited to 0.0030% or less,
B: 0% to 0.0050%,
Cr: 0% to less than 0.30%,
Mo: 0% to 1.00%,
Cu: 0% to 1.00%, and
Ni: 0% to 2.00%, and
the balance comprising iron and unavoidable impurities,
wherein an Al content and a N content, by mass %, satisfy Al−(27/14)×N>0.050%, and
a graphitization value CE, which is defined as the following equation (1), is controlled to 1.28 or less:
CE =C+Si/3−Mn/12+Al/6+Cu/9+Ni/9−Cr/9−Mo/9+B. . . ,   (1)

wherein the C, Si, Mn, Al, Cu, Ni, Cr, Mo, and B in the equation (1) indicate mass % of each element that is included in the steel for the induction hardening.

2. The steel for the induction hardening according to claim 1 , comprising, by mass %,
B: 0.0005% to 0.0050%.

3. The steel for the induction hardening according to claim 1 , comprising at least one of, by mass %,
Cr: 0.05% to less than 0.30%,
Mo: 0.01% to 1.00%,
Cu: 0.05% to 1.00%, or
Ni: 0.05% to 2.00%.

4. The steel for the induction hardening according to claim 1 , further comprising at least one of, by mass %,
Ca: 0.0005% to 0.0030%,
Zr: 0.0005% to 0.0030%, or
Mg: 0.0005% to 0.0030%.

5. The steel for the induction hardening according to claim 2 , comprising at least one of, by mass %,
Cr: 0.05% to less than 0.30%,
Mo: 0.01% to 1.00%,
Cu: 0.05% to 1.00%, or
Ni: 0.05% to 2.00%.

6. The steel for the induction hardening according to claim 2 , further comprising at least one of, by mass %,
Ca: 0.0005% to 0.0030%,
Zr: 0.0005% to 0.0030%, or
Mg: 0.0005% to 0.0030%.

7. The steel for the induction hardening according to claim 3 , further comprising at least one of, by mass %,
Ca: 0.0005% to 0.0030%,
Zr: 0.0005% to 0.0030%, or
Mg: 0.0005% to 0.0030%.

8. The steel for the induction hardening according to claim 5 , further comprising at least one of, by mass %,
Ca: 0.0005% to 0.0030%,
Zr: 0.0005% to 0.0030%, or
Mg: 0.0005% to 0.0030%.

9. The steel for the induction hardening according to claim 1 , comprising, by mass %,
Si: 0.002% to less than 0.50%.

10. The steel for the induction hardening according to claim 1 , comprising, by mass %,
O: 0.0001% to 0.0030%.

11. The steel for the induction hardening according to claim 9 , comprising, by mass %,
O: 0.0001% to 0.0030%.

12. The steel for the induction hardening according to claim 1 , further comprising, by mass %,
at least one of,
V: 0.005% to less than 0.20%,
Nb: 0.005% to 0.10%, or
Ti: 0.005% to 0.10%.

13. The steel for the induction hardening according to claim 12 , comprising, by mass %,
B: 0.0005% to 0.0050%.

14. The steel for the induction hardening according to claim 12 , comprising at least one of, by mass %,
Cr: 0.05% to less than 0.30%,
Mo: 0.01% to 1.00%,
Cu: 0.05% to 1.00%, or
Ni: 0.05% to 2.00%.

15. The steel for the induction hardening according to claim 12 , further comprising at least one of, by mass %,
Ca: 0.0005% to 0.0030%,
Zr: 0.0005% to 0.0030%, or
Mg: 0.0005% to 0.0030%.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Kubota Manabu
• Aiso Toshiharu
• Miyanishi Kei

Classifications

• C22C38/20

  with copper · CPC title

• C22C38/38

  with more than 1.5% by weight of manganese · CPC title

• C22C38/26

  with niobium or tantalum · CPC title

• C21D1/18

  Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) · CPC title

• C22C38/12

  containing tungsten, tantalum, molybdenum, vanadium, or niobium · CPC title