Title

NCC Duplex Rolls for Roughing Rod/Bar Mills

NCC Duplex Rolls for Roughing Rod/Bar Mills

Authorship

PERKS, MICHAEL

PERKS, MICHAEL

I am this author

DOI

10.5151/2594-5297-LAC01909

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Abstract

The rolls in the roughing stands of a rod/bar mill are subjected to high termal cycling causing thermal fatigue, high loads, and intermittent impact. The result is excessive wear in the box passes, and with extended campaign times, almost certainly unacceptable firecracks. The variation in surface condition, size and shape of the exiting stock leads to both high stock removal, plus extra load on subsequent stands. In extreme cases this causes cobbles and roll failure. The introduction of centrifugal cast duplex Non Continuous Carbide rolls has for similar campaign lengths reduced the stock removal due to improvement in wear resistance and thermal fatigue resistance. A higher fracture toughness reduces the degree of firecracking, and helps to extend the campaign time. The high strength spheroidal graphite core overcomes the high loads and provides a higher safety margin over standard SGP monobloc rolls. The improvement in productivity will reduce rol1 inventory, and lower rol1 cost per tonne rolled.

The rolls in the roughing stands of a rod/bar mill are subjected to high termal cycling causing thermal fatigue, high loads, and intermittent impact. The result is excessive wear in the box passes, and with extended campaign times, almost certainly unacceptable firecracks. The variation in surface condition, size and shape of the exiting stock leads to both high stock removal, plus extra load on subsequent stands. In extreme cases this causes cobbles and roll failure. The introduction of centrifugal cast duplex Non Continuous Carbide rolls has for similar campaign lengths reduced the stock removal due to improvement in wear resistance and thermal fatigue resistance. A higher fracture toughness reduces the degree of firecracking, and helps to extend the campaign time. The high strength spheroidal graphite core overcomes the high loads and provides a higher safety margin over standard SGP monobloc rolls. The improvement in productivity will reduce rol1 inventory, and lower rol1 cost per tonne rolled.

Keywords

Re-bar marking; Integrated Marking Device; ATOMAT; CNC; Tungsten Carbide Rolls

Re-bar marking; Integrated Marking Device; ATOMAT; CNC; Tungsten Carbide Rolls