Introduction
Indefinite chilled cast iron rolls also called ICCI Rolls are in the composition of alloys with cast iron. It is a roll between chilled cast iron roll and grey cast iron with a carbon content of 2.5-3.5% and a silicon content of 0.7-1.6%. The structure of the roller body changes uniformly in the outward direction and the chilled structure gradually transitions to the gray mouth structure, but the chill layer does not change significantly. The main application of the cast iron rolls are is work roll of bar & wire rod mill, hot strip mill, cold strip mill, PC mill, section mill, plate rolling mill, non-ferrous mill, etc.
The alloy indefinite chilled cast iron roll is a kind of material between cold hardened cast iron and gray cast iron. The working layer of an indefinite chilled cast iron roll body has an even distribution of graphite in the matrix structure. The graphite content increases from the surface of the roll body to the core, the hardness decreases as the depth increases, there is no obvious boundary between the working layer of the roll and the core. Infinite chilled cast iron rolls contain high chromium, nickel and molybdenum alloy elements when they contain high chromium, nickel and molybdenum alloy elements. They are produced by full flushing (overflow method) or centrifugal composite casting process. There are more carbides in the matrix structure of the working layer of the high nickel-chromium infinite chilled cast iron roll body, thus, it has higher wear resistance, and the existence of graphite in the matrix structure makes it have good thermal crack resistance.
Chemical Composition
|
Roll name |
C |
Si |
Mn |
P |
S |
Ni |
Cr |
Mo |
|
Cr-Mo infinite chilled cast iron roll |
3.20~3.70 |
0.80`1.20 |
0.60~1.00 |
≤0.20 |
≤0.10 |
/ |
0.60~1.20 |
0.20~0.60 |
|
Ni-Cr-Mo infinite chilled cast iron roll（I） |
3.20~3.70 |
0.80`1.20 |
0.60~1.00 |
≤0.20 |
≤0.10 |
0.50~1.00 |
0.70~1.20 |
0.20~0.60 |
|
Ni-Cr-Mo infinite chilled cast iron roll（II） |
3.20~3.70 |
0.60~1.00 |
0.60~1.00 |
≤0.20 |
≤0.10 |
1.01~2.00 |
0.70~1.20 |
0.20~0.60 |
|
Ni-Cr-Mo infinite chilled cast iron roll（III） |
3.20~3.70 |
0.60~1.00 |
0.60~1.00 |
≤0.20 |
≤0.10 |
2.01~3.00 |
0.70~1.20 |
0.20~0.6 |
Physical Properties
|
Roll name |
Roll-body hardness HSD |
Roll-neck hardness HSD |
Tensile strength Mpa |
|
Cr-Mo infinite chilled cast iron roll |
55~70 |
35~55 |
＞160 |
|
Ni-Cr-Mo infinite chilled cast iron roll（I） |
60~72 |
35~55 |
＞160 |
|
Ni-Cr-Mo infinite chilled cast iron roll（II） |
62~72 |
35~55 |
＞160 |
|
Ni-Cr-Mo infinite chilled cast iron roll（III） |
65~75 |
35~55 |
＞160 |
Metallographic Structure
|
Roll name |
Metallurgical structure |
|
Cr-Mo infinite chilled cast iron roll |
Pearlite + cementite + a little graphite |
|
Ni-Cr-Mo infinite chilled cast iron roll（I） |
Pearlite + cementite + a little graphite |
|
Ni-Cr-Mo infinite chilled cast iron roll（II） |
Fine pearlite + cementite + a small amount of graphite |
|
Ni-Cr-Mo infinite chilled cast iron roll（III） |
Type body + cementite + a small amount of graphite |
