Claims
- 1. A method of manufacturing a roll for hot rolling, said method comprising the steps of:
- centrifugally casting an outer layer material consisting essentially, as analyzed in weight percent, of 2.5-4.0% C, 6.0-20% Cr, 3.0-10.0% V, 0.6-5.0% Nb, 2.0-15% Mo, 3.0% or below Si, 3.0% or below Mn, C, V, Nb and Cr satisfying a following formula (1):
- 10.5(%).ltoreq.6.5.C(%)-1.3.V(%)-0.7.Nb(%).ltoreq.2.Cr(%)-2(%)(1)
- and the balance being Fe and incidental impurities;
- centrifugally casting graphite steel containing 0.5% or above of C as an intermediate layer; and
- casting an axis material,
- wherein C is present in said intermediate layer in an amount which satisfies a following formula (2):
- C (intermediate layer).gtoreq.2.0-0.5 (C-0.2 V-0.11 Nb)(outer layer)(2).
- 2. The method of manufacturing a roll for hot rolling according to claim 1, wherein the amount of Si in said roll outer layer material is between 0.1 and 1.5%, and the amount of Mn in said roll outer layer material is between 0.1 and 1.2%.
- 3. The method of manufacturing a roll for hot rolling according to claim 2, wherein said roll outer layer material further contains at least one element selected from a group consisting of 1.0% or below W, 5.0% or below Co and 1.0% or below Ni.
- 4. The method of manufacturing a roll for hot rolling according to claim 1, wherein a Mo/Cr ratio of said roll outer layer material is 0.25 or above.
- 5. The method of manufacturing a roll for hot rolling according to claim 2, wherein a Mo/Cr ratio of said roll outer layer material is 0.25 or above.
- 6. The method of manufacturing a roll for hot rolling according to claim 3, wherein a Mo/Cr ratio of said roll outer layer material is 0.25 or above.
Priority Claims (2)
Number |
Date |
Country |
Kind |
6-168643 |
Jun 1994 |
JPX |
|
7-047958 |
Feb 1995 |
JPX |
|
Parent Case Info
This is a divisional of application Ser. No. 08/494,971 filed on Jun. 26, 1995, now U.S. Pat. No. 5,674,171.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3929518 |
Akahori et al. |
Dec 1975 |
|
5316596 |
Kataoka |
May 1994 |
|
Foreign Referenced Citations (3)
Number |
Date |
Country |
0348293 |
Dec 1989 |
EPX |
3237985 |
Oct 1982 |
DEX |
1292621 |
Oct 1970 |
GBX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
494971 |
Jun 1995 |
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