Roll for rough milling rack needs to be combined with certain characteristics, among of which, some characteristics will be cancelled out by the opposite side, including abrasive resistance, thermal cracking resistance, shock resistance, thermal hardness, thermal strength, etc. Excessive net carbide is able to improve the abrasive resistance, shock resistance which then lower the fracture toughness which then will result in production of thermal cracking under rough milling situations. Therefore, in order to reduce the influence of excessive carbide but also maintain the abrasive resistance, Ni and Mo must be added to let the matrix under bainite/ martensite (acicular) which is more wearable then ordinary matrix in pearlite. The Mo element is also good to improve harness of roll under high temperature.
GNV Roll is made of high-alloy materials through special heat treatment, the content of carbide in the matrix is lower than 5% so as to meet requirement from rough rolling rack.
Chemical Composition
|
Mark |
C |
Si |
Mn |
Cr |
Ni |
Mo |
V |
|
GNV-A |
3.00-3.40 |
2.00-2.50 |
0.80-1.00 |
≥0.15 |
2.50-4.00 |
0.70-1.00 |
0.15-0.35 |
|
GNV-B |
3.00-3.40 |
1.50-2.00 |
0.80-1.00 |
≥0.15 |
2.50-4.50 |
0.70-1.00 |
0.15-0.35 |
Performance and Application
|
Mark |
Hardness （HS） |
Tensile strength（Mpa） |
Bending strength（Mpa） |
Purpose |
|
GNV-A |
40-50 |
≥510 |
900-1360 |
Rough rolling rack for rod and wire materials |
