Claims
- 1. A method of manufacturing a forged roll for rolling a seamless steel pipe, wherein a high carbon alloy cast steel, which comprises about 1.10-1.85 wt % carbon, about 0.3-1.2 wt % silicon, about 0.4-1.5 wt % manganese, about 0.5-2.0 wt % nickel and about 0.5-2.0 wt % chromium and a remaining portion substantially consisting of iron, is hot-forged so as to be roll-shaped, said roll is cooled down to about 600.degree. C. or less at a cooling rate of about 2.5.degree. C./min or more, a first stage heat treatment for spheroidal carbide formation is performed wherein said roll is maintained for about five hours or more at a temperature from about (Acm minus 10.degree. C.) to (Acm minus 100.degree. C.), and wherein a second stage heat treatment is performed and effects spheroidal carbide formation within said roll.
- 2. The method according to claim 1, wherein at least one of about 0.1-1.0 wt % molybdenum, about 0.1-1.0 wt % vanadium and about 0.1-1.0 wt % tungsten is added to said high carbon alloy cast steel.
- 3. The method according to claim 1, wherein the total content of detrimental-to-forging elements of said high carbon alloy cast steel, selected from the group consisting of phosphorus, sulfur, copper, arsenic, tin, lead, zinc, antimony and bismuth, is about 0.2 wt % or less.
- 4. The method according to claim 2, wherein the total content of detrimental-to-forging elements of said high carbon alloy cast steel, selected from the group consisting of phosphorus, sulfur, copper, arsenic, tin, lead, zinc, antimony and bismuth, is about 0.2 wt % or less.
- 5. The method according to claim 1, wherein said second stage heat treatment for spheroidal carbide formation is performed at a temperature range from about 700 to 840.degree. C.
- 6. The method according to claim 2, wherein said second stage heat treatment for spheroidal carbide formation is performed at a temperature range from about 700 to 840.degree. C.
Priority Claims (1)
Number |
Date |
Country |
Kind |
8-170328 |
Jun 1996 |
JPX |
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Parent Case Info
This application is a divisional of application Ser. No. 08/881,231, filed Jun. 24, 1997, incorporated herein by reference, now U.S. Pat. No. 5,813,962.
US Referenced Citations (11)
Foreign Referenced Citations (4)
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0 395 477 |
Oct 1990 |
EPX |
57-126914 |
Aug 1982 |
JPX |
60-012211 |
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JPX |
1 025 680 |
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GBX |
Divisions (1)
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Number |
Date |
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Parent |
881231 |
Jun 1997 |
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