Rolls


Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Idioms.
Related to Rolls: Dinner rolls

Rolls

 

the working members (instruments) of a rolling mill. Rolls perform the basic rolling operation: the deformation (reduction) of the metal to give it the required dimensions and shape. The rolls consist of three elements: the barrel, two journals (trunnions), and the driving end (the “wobbler”). Rolls are divided into flattening and fluted types. Flattening rolls are used to roll sheets, plates and strips, and bars; the barrel of such a roll is cylindrical, slightly convex or concave. (Such rolls are also called smooth.) Fluted rolls are used to roll shaped (fluted) metal (circular or square cross sections, rails, I-beams, and so on); the grooves that correspond to the profile of the metal to be formed are made in the barrel surfaces of these rolls. The notches are called passes (the passes of two rolls form gauges), and the rolls are called grooved (gauging) rolls.

The basic dimensions of rolls (diameter and barrel length) depend on the gauge of the rolled product. The roll diameter for hot rolling is 250-300 mm (wire rolling) to 1,000-1,400 mm (bloom and slab rolling). For cold rolling, rolls are used with diameters from 5 mm (in 20-roll mills in foil rolling) to 600 mm (in quarto mills in the rolling of thin strips).

Cast-iron rolls with a Shore hardness of 35-45 (produced by casting in sand-clay molds) are the least expensive and are used in the hot rolling of soft strip steel; cast-iron rolls with a Shore hardness of 55-75 (produced by casting in metallic molds—chill molds) are used in sheet mills and in the finishing stands of section and wire mills; alloyed (with chromium, nickel, or molybdenum) cast-iron rolls with a Shore hardness of 40-70 are used in section rail and structural and thin-sheet hot-rolling mills; and steel rolls are used in blooming mills, slabbing mills, reduction stands of section mills and in cold-rolling mills. The working rolls of small multiple-roll mills, as well as flatting mills for the spreading of high-strength steel wire, are produced from ceramic hard tungsten-carbide alloys (with cobalt added); the wear resistance of such rolls is 30-50 times greater than that of steel alloyed rolls. Wear-resistant and strong rolls for section and sheet rolling are obtained by metal surfacing with hard and superhard alloys.

Worn rolls are restored by returning on roll-turning lathes or regrinding (for sheet-mill rolls) on roll-grinding lathes.

REFERENCES

Tselikov, A. I., and V. V. Smirnov. Prokatnye stany. Moscow, 1958.
Korolev, A. A. Mekhanicheskoe oborudovanie prokatnykh tsekhov, 2nd ed. Moscow, 1965.

P. I. POLUKHIN


Rolls

 

the operating members of crushing, flour-milling, punching, and other machines in the form of smooth or grooved rolls, cylinders, or cones (generally rotating in different directions) that process the material passing between them; they include forging rolls, crushing rolls, and others.

References in classic literature ?
On the contrary, the coach begins to roll back upon No.
As he drew near the advancing soldiers, and as the roll of their drum came full upon his ears, the old man raised himself to a loftier mien, while the decrepitude of age seemed to fall from his shoulders, leaving him in gray but unbroken dignity.
At the old man's word and outstretched arm, the roll of the drum was hushed at once, and the advancing line stood still.
Several times Condon attempted to draw the lad into a card game; but his victim was not interested, and the black looks of several of the other men passengers decided the American to find other means of transferring the boy's bank roll to his own pocket.
The American's fingers felt swiftly through them--the pockets contained no roll of crisp, new notes.
He felt for the bank roll in the pocket in which he had been accustomed to carry it.
The Saw-Horse now became quiet, and held its legs rigid; so that Tip, after several efforts, was able to roll him over and set him upright.
Tapered rolls are larger in diameter at one end than the other.
The top and bottom rolls are polymer covered as are the third, fifth, and sixth rolls.
The calender rolls must be ground periodically to establish the proper profile.
Spring being officially here - though you wouldn't know it from our recent weather - the season points to the light and tasty versions of Asian-influenced spring rolls that local restaurant chefs seem to have a great time fashioning.
It uses not one, but two separate sets of conditioner rolls positioned in-line for double conditioning.