Relevance

There are two sizes available for tube mills with three-roller mill: 50-200 and 40-160. The advantage of these mills is the high precision of the tubes, the possibility of comprehensive automation and the fast transition to other tube sizes.

Tolerances

The tolerances for the outer diameter in tube rolling are ±0.5 % and +6 % for the wall thickness. These tolerances allow steel consumption to be reduced, for example at machine shops where pipes are turned.

Production technology

The plant described consists of a piercing mill, a mandrel extractor, a three-roll piercing and a rolling mill, a heating and reheating furnace, a cooling table and a 5-high roll piercing mill. The billet for rolling is a round rod; it is cut to finished lengths on a hydraulic press. The round billet is heated in a circular heating furnace to 1150-1250°С, and pierced in a sleeve in the piercing mill. Then the hot tubes (t° 1000-1100 ° C) passes through the unrolling on the long mandrel of the sleeve.

The mill has 3 rolls that rotate in one direction. In relation to the rolling axis the rolls are arranged strictly symmetrically. In the horizontal plane, the axes of the rolls are inclined to the rolling axis at a rolling angle p°, which is usually 7° in these mills. In the vertical plane, the axes of the rolls are inclined to the rolling axis at a feed angle of 4° to 10° (the angle depends on the size of the tubes being rolled).

Each roll has four sections: the comb, the rolling cone, the gripping cone and the calibrating cone. In the gripping cone the metal is deformed by reducing the tube diameter and also by rolling out the tube wall on a long mandrel. Deformation of the wall mainly takes place through the comb of the roll. The rolling cone rolls out the pipe wall, which results in a smooth and even surface over the entire length. The rounding of the outer diameter is carried out by the calibrating cone, which is also responsible for the retraction of the tube from the mandrel, thus making it easier to retrieve.

The rolling process in a rolling mill is similar to roll piercing. The rolls, which rotate to one side, grab the sleeve and it receives a rotary movement. Due to the inclination of the rolls, the sleeve also receives a translational movement. The rolled tube is reheated to 1000-1100°C in the reheating furnace, after which the tube is taken to the calibration mill (5-roll or 3-roll), where the outside diameter is calibrated. Then the tube is sent to a cooling table.

Buy, price

Evek GmbH sells rolled steel products at an optimal price. It is formed taking into account the LME rates (London metal exchange) and depends on the technological characteristics of production, without including additional costs. We deliver stainless steel pipes of standard and non-standard sizes in wide assortment. All batches of products have the certificate of quality for compliance with standards. With us you can buy in bulk the most various products for large-scale productions. The wide choice, exhaustive consulting of our managers, reasonable prices and timely delivery determine the face of our company. There is a system of discounts for wholesale purchases.