Claims
- 1. A steel for metal mold for molding glass which consists of 0.25-0.65% of C, up to 2.50% of Si, up to 2.00% of Mn, 10.00-20.00% of Cr, 4.00-13.00% of Co, 1.00-3.00% of Al, up to 0.25% of N and the balance essentially Fe and ordinary impurities and satisfies the relation:
- Cr equivalent=-40C(%)+6Si(%)-2Mn(%)+Cr(%)-2Co(%)-30N(%)+12Al(%).ltoreq.13%
- and which has a single phase of martensite by a heat treatment for hardening and tempering and has a standard hardness of H.sub.B 229-293 after said heat treatment.
- 2. A steel for metal mold for molding glass which consists of 0.30-0.50% of C, up to 2.00% of Si, up to 1.00% of Mn, 12.00-18.00% of Cr, 4.00-8.00% of Co, 1.50-2.50% of Al, up to 0.25% of N and the balance essentially Fe and ordinary impurities and satisfies the relation:
- Cr equivalent=-40C(%)+6Si(%)-2Mn(%)+Cr(%) -2Co(%)-30N(%)+12Al(%).ltoreq.13%
- and which has a single phase of martensite by a heat treatment for hardening and tempering and has a standard hardness of H.sub.B 229-293 after said heat treatment.
- 3. A metal mold for molding glass that provides a glass casting surface without being chromium-plated and that is formed of a steel which consists essentially of 0.25-0.65% of C, up to 2.50% of Si, up to 2.00% of Mn, 10.00-20.00% of Cr, 4.00-13.00% of Co, 1.00-3.00% of Al, up to 0.25% of N and the balance essentially Fe and ordinary impurities and satisfies the relation:
- Cr equivalent=-40C(%)+6Si(%)-2Mn(%)+Cr(%)-2Co(%)-3ON(%)+12A1(%).ltoreq.13%
- and which has a single phase of martensite by a heat treatment for hardening and tempering and has a standard hardness of H.sub.B 229-293 after said heat treatment.
- 4. A metal mold for molding glass that provides a glass casting surface without being chromium-plated and that is formed of a steel which consists essentially of 0.30-0.50% of C, up to 2.00% of Si, up to 1.00% of Mn, 12.00-18.00% of Cr, 4.00-8.00% of Co, 1.50-2.50% of Al, up to 0.25% of N and the balance essentially Fe and ordinary impurities and satisfies the relation:
- Cr equivalent=-40C(%)+6Si(%)-2Mn(%)+ Cr(%)-2Co(%)-30N(%)+12Al(%).ltoreq.13%
- and which has a single phase of martensite by a heat treatment for hardening and tempering and has a standard hardness of H.sub.B 229-293 after said heat treatment.
Priority Claims (1)
Number |
Date |
Country |
Kind |
47-93589 |
Sep 1972 |
JPX |
|
CROSS REFERENCE TO THE RELATED APPLICATION
This is a continuation-in-part of the U.S. Ser. No. 490,655 filed on July 22, 1974 which is now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (1)
Number |
Date |
Country |
49-6013 |
Jan 1974 |
JPX |
Non-Patent Literature Citations (1)
Entry |
"A Dictionary of Metallurgy", A. D. Merriman, 1958, pp. 180-181. |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
490655 |
Jul 1974 |
|