Outer-layer material for hot-rolling roll, and hot-rolling composite roll

Patent metadata

Field	Value
Publication number	US-9573176-B2
Application number	US-201314427759-A
Country	US
Kind code	B2
Filing date	Sep 6, 2013
Priority date	Sep 13, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A surface layer material of a hot rolling mill roll is provided. The surface layer has a chemical composition containing, by mass %, C: 2.4% or more and 3.5% or less, Si: 1.2% or more and 2.4% or less, Mn: 0.2% or more and 2.0% or less, Cr: 0.8% or more and 2.1% or less, Mo: 0.3% or more and 1.1% or less, Ni: 3.0% or more and 6.0% or less, V: 1.0% or more and 2.2% or less, Nb: 0.1% or more and 0.5% or less, REM: 0.0005%) or more and 0.1% or less, Al: 0.003% or more and 0.05% or less, and the balance being Fe and inevitable impurities. The contents of C, Cr, V, Nb, REM, and Al satisfy the relationships Cr+0.2≦C−(0.24×V+0.13×Nb)≦3.0 and 0.01≦REM/Al≦3.2.

First claim

The invention claimed is:

1. A surface layer material of a hot rolling mill roll which is adapted to be used for a surface layer of a hot rolling mill composite roll, the material having a chemical composition containing, by mass%, C: 2.4% or more and 3.5% or less, Si: 1.2% or more and 2.4% or less, Mn: 0.2% or more and 2.0% or less, Cr: 0.8% or more and 2.1% or less, Mo: 0.3% or more and 1.1% or less, Ni: 3.0% or more and 7.0% or less, V: 1.2% or more and 2.2% or less, Nb: 0.1% or more and 0.8% or less, REM: 0.0005% or more and 0.1% or less, Al: 0.003% or more and 0.05% or less, and the balance being Fe and inevitable impurities, wherein the contents of C, Cr, V, Nb, REM, and Al satisfy relational expressions (1) and (2) below:
Cr+0.2≦C−(0.24×V+0.13×Nb)≦3.0  (1)

0.01≦REM/Al≦3.2  (2),

where C, Cr, V, Nb, REM, and Al respectively represent the mass% contents of the corresponding chemical elements.

2. The surface layer material of the hot rolling mill roll according to claim 1 , wherein the chemical composition of the material further contains, by mass %, B: 0.001% or more and 0.05% or less.

3. The surface layer material of the hot rolling mill roll according to claim 1 , wherein the chemical composition of the material further contains, by mass % at least one of the following element: Ca: 0.04% or less and Ti: 0.03% or less.

4. The surface layer material of the hot rolling mill roll according to claim 1 , wherein the chemical composition of the material further contains, by mass %, at least one of the following elements: Co: 2.0% or less and W: 2.0% or less.

5. A hot rolling mill composite roll comprising:
an inner layer, and
a surface layer welded and, integrated with the inner layer,
the surface layer having a chemical composition containing, by mass%, C: 2.4% or more and 3.5% or less, Si: 1.2% or more and 2.4% or less, Mn: 0.2% or more and 2.0% or less, Cr: 0.8% or more and 2.1% or less, Mo: 0.3% or more and 1.1% or less, Ni: 3.0% or more and 7.0% or less, V: 1.2% or more and 2.2% or less, Nb: 0.1% or more and 0.8% or less, REM: 0.0005% or more and 0.1% or less, Al: 0.003% or more and 0.05% or less, and the balance being Fe and inevitable impurities,
wherein the contents of C, Cr, V, Nb, REM, and Al satisfy relational expressions (1) and (2) below:
Cr+0.2 ≦C−(0.24×V+0.13×Nb)≦3.0  (1)

0.01 ≦REM/Al≦3.2  (2),

where C, Cr, V, Nb, REM, and Al respectively represent the mass% contents of corresponding chemical elements.

6. The hot rolling mill composite roll according to claim 5 , wherein the chemical composition of the surface layer further contains, by mass %, B: 0.001% or more and 0.05% or less.

7. The hot rolling mill composite roll according to claim 5 , wherein the chemical composition of the surface layer further contains, by mass %, at least one of the following elements: Ca: 0.04% or less and Ti: 0.03% or less.

8. The hot rolling mill composite roll according to claim 5 , wherein the chemical composition of the surface layer further contains, by mass %, at least one of following elements: Co: 2.0% or less and W: 2.0% or less.

9. The surface layer material of the hot rolling mill roll according to claim 2 , wherein the chemical composition of the material further contains, by mass%, at least one of the following elements: Ca: 0.04% or less and Ti: 0.03% or less.

10. The surface layer material of the hot rolling mill roll according to claim 2 , wherein the chemical composition of the material further contains, by mass%, at least one of the following elements: Co: 2.0% or less and W: 2.0% or less.

11. The surface layer material of the hot rolling mill roll according to claim 3 , wherein the chemical composition of the material further contains, by mass%, at least one of the following elements: Co: 2.0% or less and W: 2.0% or less.

12. The surface layer material of the hot rolling mill roll according to claim 9 , wherein the chemical composition of the material further contains, by mass%, at least one of the following elements: Co: 2.0% or less and W: 2.0% or less.

13. The hot rolling mill composite roll according to claim 6 , wherein the chemical composition of the surface layer further contains, by mass%, at least one of the following elements: Ca: 0.04% or less and Ti: 0.03% or less.

14. The hot rolling mill composite roll according to claim 6 , wherein the chemical composition of the surface layer further contains, by mass%, at least one of the following elements: Co: 2.0% or less and W: 2.0% or less.

15. The hot rolling mill composite roll according to claim 7 , wherein the chemical composition of the surface layer further contains, by mass%, at least one of the following elements: Co: 2.0% or less and W: 2.0% or less.

16. The hot rolling mill composite roll according to claim 13 , wherein the chemical composition of the surface layer further contains, by mass%, at least one of the following elements: Co: 2.0% or less and W: 2.0% or less.

Assignees

• Jfe Steel Corp

Inventors

• Ichino Kenji
• Mochida Tetsuo
• Shibata Hiromitsu

Classifications

• C22C38/005

  containing rare earths, i.e. Sc, Y, Lanthanides · CPC title

• C22C37/08 Primary

  with nickel · CPC title

• C22C37/10

  containing aluminium or silicon · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• B21B27/03 Primary

  Sleeved rolls {(B21B27/028 takes precedence)} · CPC title