How rolling production is organized

Rolling production is an integral part of the metallurgical industry, creating a wide range of metal products, from sheets and bars to tubes and beams. At the heart of this type of production lies the rolling process, in which metal is subjected to compression and thinning between rotating rolls of rolling mills. In this article we will consider the main stages of rolling, features of rolling mills, and also the significance of rolling in the metallurgical industry.

Features of rolling production

Rolling production has a number of features that make it important and in demand in the metallurgical industry:

1. High productivity. Rolling equipment is able to process large volumes of metal in a short time, which makes it possible to quickly and efficiently produce various kinds of rolled products.
2. Economy of production. Rolling is a relatively cheap way of producing metal products compared with other methods such as casting or powder metallurgy.
3. Wide product range. On rolling equipment various kinds of metal products differing in sizes, shape, and characteristics can be produced, making it universal and in demand on the market.
4. Production flexibility. Rolling equipment is easily configured to produce products of various types and sizes, which makes it possible to adapt the production process to specific customer needs.
5. High product quality. Rolling equipment ensures elevated accuracy and quality of metal processing, which makes it possible to release products with high strength and other characteristics.

Rolling is the most widespread method of forming metal under pressure. The amount of rolled metal produced by metallurgical enterprises is one of the most important assessments of the development level of the metallurgical industry in a country.

The rolling production process

The rolling process is sequential compression and stretching of metal using rotating rolls. It occurs on special devices called rolling mills. The rolling scheme is shown in Figure 1, where:

• H — initial blank thickness;
• h — distance between rolls, as well as blank thickness after passing between the rolls of the rolling mill.

Figure 1 - Rolling scheme

The rolling process: main stages

First stage: blank

At the initial stage metal semi-finished products are fed between the rotating rolls of the mill. The blank may have various shapes and sizes, but during processing its length increases and its height decreases.

Second stage: rolling

Carried out by compressing metal between rotating rolls. This leads to a change in blank sizes and shape. The degree of reduction is determined by the formula (H−h)/H·100%.

Third stage: product formation

As a result of the rolling process the metal acquires a new shape and sizes. Depending on the rolling mill configuration and process parameters, various kinds of rolled products can be obtained: tubes, sheets, strips, bars, and others.

Types and features of rolling mills

A device in which metal is crushed and thinned by rolling it between rotating rolls is called a stand. A rolling mill consists of several stands equipped with specialized auxiliary devices and connected to each other.

Rolling mills differ in design and purpose. The main types of rolling mills include:

• sheet mills — intended for producing sheet material;
• tube mills — specialize in producing tubes;
• section mills — used to produce bars, beams, and strips;
• rail-beam mills — intended for manufacturing rails and beams;
• special mills — adapted for producing specific kinds of products.

Depending on the state in which the processed metal is, mills may be either hot or cold rolling.

Cold-rolled and hot-rolled products

PZPS is equipped with a unique strip hot-rolling mill with capacity up to 600 tonnes per month of hot-rolled strip of width from 80 mm to 250 mm and thickness from 2.0 mm to 4.0 mm. At the customer’s request hot-rolled strip up to 16 mm thick can be manufactured.

PZPS is also equipped with high-productivity cold-rolling mills with capacity up to 600 tonnes per month.

By sheet thickness one distinguishes:

• thin sheet rolled products — up to 4 mm;
• thick — more than 4 mm.

At PZPS thin sheet rolled products can be obtained in the thickness needed by the customer. Production of especially thin (micron) strip up to 5 μm thick is also possible. For ordering and purchasing hot-rolled and cold-rolled strip and sheets of needed sizes, call +7 (812) 740–76–55 or leave requests on the website. Our employees will contact you and answer all questions in detail.

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