Centrifugally cast, hot-rolling composite roll

Patent metadata

Field	Value
Publication number	US-9718106-B2
Application number	US-201414912511-A
Country	US
Kind code	B2
Filing date	Sep 17, 2014
Priority date	Sep 25, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A centrifugally cast, hot-rolling composite roll comprising an outer layer formed by a centrifugal casting method, and an inner layer made of ductile cast iron and integrally fused to the outer layer; the outer layer having a chemical composition comprising by mass 1-3% of C, 0.4-3% of Si, 0.3-3% of Mn, 1-5% of Ni, 2-7% of Cr, 3-8% of Mo, 3-7% of V, and 0.01-0.12% of B, the balance being Fe and inevitable impurities, and meeting the relation expressed by Cr/(Mo+0.5W)<−2/3[C−0.2(V+1.19Nb)]+11/6, wherein W=0, and Nb=0, when W and Nb are not contained; and containing by area 1-15% of MC carbide, 0.5-20% of carboboride, and 0.5-20% of Mo-based carbide.

First claim

What is claimed is:

1. A centrifugally cast, hot-rolling composite roll comprising an outer layer formed by a centrifugal casting method, and an inner layer made of ductile cast iron and integrally fused to said outer layer;
said outer layer having a chemical composition comprising by mass 1-3% of C, 0.4-3% of Si, 0.3-3% of Mn, 1-5% of Ni, 2-7% of Cr, 3-8% of Mo, 3-7% of V, and 0.01-0.12% of B, the balance being Fe and inevitable impurities, and meeting the relation expressed by the following formula (1):
Cr/(Mo+0.5W)<−2/3[C−0.2(V+1.19Nb)]+11/6  (1),

wherein W=0, and Nb=0, when W and Nb, optional components, are not contained; and
said outer layer containing by area 1-15% of MC carbide, 0.5-20% of carboboride, and 0.5-20% of Mo-based carbide.

2. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises 3% or less by mass of Nb and/or 4% or less by mass of W.

3. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises 0.05-0.3% by mass of S.

4. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises 0.01-0.07% by mass of N.

5. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti, and 0.5% or less of Al.

6. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer meets the relation expressed by the following formula (2):
30.23+2.74×(area ratio of MC carbide)+4.01×(area ratio of Mo-based carbide)−5.63×(area ratio of carboboride)≦50  (2).

7. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer has Vickers hardness Hv of 500 or more.

8. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 3% or less of Nb and/or 4% or less by mass of W, and 0.05-0.3% of S.

9. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 3% or less of Nb and/or 4% or less by mass of W, and 0.01-0.07% of N.

10. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 0.05-0.3% of S, and 0.01-0.07% of N.

11. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 3% or less of Nb and/or 4% or less by mass of W, 0.05-0.3% of S, and 0.01-0.07% of N.

12. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 3% or less of Nb and/or 4% or less by mass of W, and at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti and 0.5% or less of Al.

13. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 0.05-0.3% of S, and at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti and 0.5% or less of Al.

14. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 0.01-0.07% of N, and at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti and 0.5% or less of Al.

15. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 0.05-0.3% of S, 0.01-0.07% of N, and at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti and 0.5% or less of Al.

16. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 3% or less of Nb and/or 4% or less by mass of W, 0.05-0.3% of S, and at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti and 0.5% or less of Al.

17. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 3% or less of Nb and/or 4% or less by mass of W, 0.01-0.07% of N, and at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti and 0.5% or less of Al.

18. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein said outer layer further comprises by mass 3% or less of Nb and/or 4% or less by mass of W, 0.05-0.3% of S, 0.01-0.07% of N, and at least one selected from the group consisting of 5% or less of Co, 0.5% or less of Zr, 0.5% or less of Ti and 0.5% or less of Al.

19. The centrifugally cast, hot-rolling composite roll according to claim 1 , wherein the chemical composition of the outer layer has a C content of by mass 1-2.9%.

Assignees

• Hitachi Metals Ltd

Inventors

• Hattori Toshiyuki
• Oda Nozomu
• Nozaki Yasunori

Classifications

• C22C2204/00

  End product comprising different layers, coatings or parts of cermet · CPC title

• C22C38/58

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

• C22C38/56

  with more than 1.7% by weight of carbon · CPC title

• C22C38/54

  with boron · CPC title

• C22C38/52

  with cobalt · CPC title