|
CHARACTERISTICS |
These rolls have high wear
resistant shell with minimal drop in hardness &
having good resistance to thermal shock and
thermal fatigue with higher level of resistance
to oxidation at high temperatures of operation
in the mill. The shell matrix contains
martensite, bainite and finely dispersed
carbides which imparts excellent wear resistance
and high thermal fatigue resistance. Core
material is always SG Iron imparting better
strength for application in hot strip mills.
These rolls require high degree of cooling in
the mill during operation. It also requires
proper monitoring o cracks during dressing
through Eddy Current & Ultrasonic Testing.
The campaign life of these rolls, under standard
mill conditions, are almost double that of Hi Cr
Iron rolls requiring very less dressing per
campaign. |
|
APPLICATION |
| These rolls are suitable for
initial finishing stands of Hot Strip Mills. |
|
MECHANICAL PROPERTIES |
|
|
|
65-75 (In steps of 5°ShC)
|
|
75-85 (In steps of 5°ShC) |
|
|
Neck
Properties (SG Core) |
|
Hardness (°Sh-C) |
U.T.S (N/mm2 |
Impact (J/cm2) |
|
35-45 |
400-500 |
3.50 max |
|
|
|
CHEMICAL COMPOSITION (SHELL-1) |
|
C |
Si |
Ni |
Cr |
Mo |
V |
W |
Nb |
|
2.40 |
0.60 |
0.70 |
5.50 |
3.50 |
3.00 |
- |
0.80 |
|
2.80 |
1.20 |
1.20 |
7.00 |
4.50 |
4.50 |
- |
1.50 |
|
CHEMICAL COMPOSITION (SHELL-2) |
|
C |
Si |
Ni |
Cr |
Mo |
V |
W |
Nb |
|
1.90 |
0.90 |
0.80 |
4.20 |
1.80 |
5.00 |
1.80 |
- |
|
2.10 |
1.20 |
1.00 |
4.60 |
2.20 |
5.50 |
2.20 |
- |
|
CHEMICAL COMPOSITION (SHELL-1) |
|
C |
Si |
Ni |
Cr |
Mo |
V |
W |
Nb |
|
3.00 |
1.90 |
1.00 |
0.60 |
- |
0.03 |
- |
- |
|
3.30 |
2.70 |
Max |
Max |
- |
0.07 |
- |
- |
|
