The main basis for selecting a rolling mill is the steel grade, product variety and specifications, production scale, and the determined product production process of the steel produced in the workshop.

When selecting a rolling mill, the following principles should generally be considered:

1) Under the premise of concealing the product plan, make the rolling mill composition reasonable and layout compact;

2) Having high production efficiency and equipment utilization coefficient;

3) Ensure the acquisition of high-quality products and consider the possibility of producing new products;

4) It is conducive to the realization of mechanization and automation of rolling mills, and helps to improve the working conditions of workers;

5) The rolling mill structure is advanced and reasonable, easy to manufacture, easy to operate, and easy to maintain;

6) Easy replacement of spare parts and conducive to achieving standardization of spare parts;

7) Having good comprehensive technical and economic indicators.

For wire rod mills, steel tube mills, and steel plate mills, in addition to a certain degree of strength, sufficient stiffness is also required to ensure the correct geometric shape and accurate dimensions of these rolled products. Therefore, when selecting a rolling mill, in addition to following the general principles mentioned above, the structural type, main technical parameters, and layout of the rolling mill should be determined based on the production characteristics and specific requirements of different products, starting from the process requirements of the product.

Comparison of Rolling Mill Layout Selection

Horizontal rolling mill

Horizontal rolling mills, especially rough rolling mills, require multiple passes of rolling, with slow rolling speed and long rolling rhythm. However, due to the small cross-section of the billet, rapid temperature drop of the rolled piece, and large temperature difference between the head and tail, it is necessary to choose a rapid extension pass system as much as possible to minimize the number of rolling passes when given the billet size and finished product specifications. For example, elliptical square and hexagonal square hole types. The rolling mill arranged horizontally has the same rotational speed of the rollers in the same train, and the rolling speed does not increase with the increase of the length of the rolled piece. Therefore, the output is small, the labor productivity of the rolling mill is low, and the quality of the rolled products is poor, making it difficult to achieve automatic control. It has been phased out abroad. This is an important drawback of the horizontal layout rolling mill.

Tandem rolling mill

Adopting tracking rolling method, each rolling mill only rolls one pass, and each rolling mill has different rolling speeds, which can increase the rolling speed with the increase of the length of the rolled piece, thus having high productivity. Each rolling mill only rolls once, with a roll L/D of 1.5-2.5. The frames are mostly closed, with high stiffness and product accuracy, without continuous rolling. Each frame does not affect each other, making it easy to adjust.

However, the length of the rolled piece increases with the increase of passes. The distance between frames also increases with the increase of the length of the rolled piece. Therefore, the rolling mill arranged in a sequential manner has a longer factory building, resulting in an increase in workshop area and investment. Therefore, it is only suitable for producing steel with larger cross-sectional dimensions or for rough rolling mill trains arranged in other forms.