Claims
- 1. A low alloy steel for use in a pressure vessel consisting essentially of on a weight % basis:
- C: from 0.05% to 0.20%,
- Si: less than 0.10%,
- Mn: from 0.3% to 1.5%,
- Ni: from a trace impurity level to 0.55%,
- Cr: from 1.5% to 5.5%,
- Mo: from 0.5% to 1.5%,
- V: in excess of 0.3% and less than 0.6%,
- Nb: from 0.05% to 0.08%,
- Ca: from 0.0005% to 0.02%, and
- the balance of iron and inevitably incorporated impurities.
- 2. The alloy steel of claim 1, further comprising Zr satisfying the relationship of 0.0005% .ltoreq.(Ca+Zr).ltoreq.0.02%.
- 3. The alloy steel of claim 1, further comprising at least one rare earth element in an amount of from 0.01% to 0.02%.
- 4. The alloy steel of claim 1, wherein V is present in an amount of in excess of 0.3% to 0.05%.
- 5. A low alloy steel for use in a pressure vessel consisting essentially of on a weight % basis:
- C: from 0.05% to 0.20%,
- Si: less than 0.10%,
- Mn: from 0.3% to 1.5%,
- Ni: from a trace impurity level to 0.55%,
- Cr: from 1.5% to 5.5%,
- Mo: from 0.5% to 1.5%,
- V: from 0.34% to less than 0.6%,
- Nb: from 0.05% to 0.08%,
- Ca: from 0.0005% to 0.02%, and
- the balance of iron and inevitably incorporated impurities.
- 6. The alloy steel of claim 5, further comprising Zr satisfying the relationship of 0.0005%.ltoreq.(Ca +Zr).ltoreq.0.02%.
- 7. The alloy steel of claim 5, further comprising at least one rare earth element in an amount of from 0.01% to 0.02%.
- 8. The alloy steel of claim 5, wherein V is present in an amount of 0.34% to 0.5%.
Priority Claims (1)
Number |
Date |
Country |
Kind |
59-39628 |
Feb 1984 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 883,424, filed on July 14, 1986, which is a continuation of application Ser. No. 704,853, filed Feb. 25, 1985, both now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3291655 |
Gill et al. |
Dec 1966 |
|
4381940 |
Watanabe et al. |
May 1983 |
|
4461657 |
Rana et al. |
Jul 1984 |
|
Foreign Referenced Citations (2)
Number |
Date |
Country |
584495 |
Oct 1959 |
CAX |
923735 |
Apr 1973 |
CAX |
Continuations (2)
|
Number |
Date |
Country |
Parent |
883424 |
Jul 1986 |
|
Parent |
704853 |
Feb 1985 |
|