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High Speed Steel
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Double Pour, Nodular Core
Specially developed for use as work rolls in the early finishing stands of hot strip mills. High Speed Steel rolls are centrifugally cast double poured and consist of a shell of high carbon high speed steel with journals and barrel axis of nodular cast iron.
This type of roll is particularly suitable for mills requiring the highest standards of surface finish and dimensional control where the exceptional wear resistance reduces the need for frequent roll changes, so enhancing mill productivity.
The structure of the shell metal consists of globular primary carbides in a tempered martensitic matrix with fine secondary carbides. The carbon content of the shell metal is higher than that found in conventional high speed steels so as to increase the carbide content to give levels of wear resistance previously unheard of for this type of roll.
The fine microstructure and high hardenability of this material mean that there is no fall-off in hardness to discard so ensuring consistently excellent performance throughout the life of the roll. The core material for any double poured High Speed Steel roll will be of nodular iron, which provides greater mechanical strength which is important in mills using roll bending and shifting systems.
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Applications
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| Product |
Type of Mill |
Position |
| Wide Strip |
4 High |
Finishing |
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Typical Mechanical Properties
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N/mm2 |
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Barrel |
Journal & Axis |
| Property |
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Nodular Core |
| Tensile Strength |
1050 |
480 |
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Typical Hardness Gradient
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Micrograph
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Shell x 500
Nodular Core x 50
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Typical Analysis
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| Code |
Leeb E |
Shore C |
C |
Si |
Mn |
Ni |
Cr |
Mo |
V |
W |
| HSS |
680-820 |
65-90 |
1.0/2.5 |
0.5/1.0 |
0.1/1.0 |
0.1/1.0 |
4.5/9.5 |
0.5/4.5 |
4.0/6.0 |
0.5/6.0 |
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