Configuration of Rolling Mills

In the process of rolling profiles by rolling mills, there are usually two processes of rough rolling and finish rolling, one of which adopts continuous rolling and the other adopts a combined rolling method of other non-continuous rolling, which is commonly used for alloy steel rolling or transformation of old equipment.

Among them, there are two forms of semi-continuous rolling of profiles, one is continuous rolling of rough rolling and shuttle rolling or looper rolling of horizontal rolling mill; The other is that rough rolling is horizontal rolling mill, shuttle rolling is adopted, and finish rolling is continuous rolling.

At present, the rolling method of double and double rolling mill used in some small workshops belongs to a special semi-continuous rolling method, Continuous rolling is carried out between the front and rear stands, and looper rolling is carried out between two adjacent groups of rolling mills with surrounding coils. When the finishing rolling process is continuous rolling, the rolling speed is not limited and the output is high, but the rolling mill adjustment is complicated, the product variety is difficult to change, the production is inflexible, and it is suitable for batch production of small varieties of simple cross-section profiles.

However, when its finishing rolling process is shuttle rolling or looper rolling by horizontal rolling mill, it is convenient to change rolling varieties, but the rolling speed is low and the output is low, which is suitable for rolling special-shaped profiles and small batch production of multiple varieties. This kind of equipment has the advantages of compact arrangement, convenient adjustment, multi-wire rolling and high output.

In addition to continuous and semi-continuous rolling, the rolling mill can also adopt slitting rolling process for production. Under the same conditions, this process can reduce the heating temperature of billet by about 40 ℃, fuel by 20%, power consumption by 15%, and total production cost by 10-15%. Therefore, slitting rolling is an easy and effective measure to reduce production cost.

Compared with ordinary rolling, the product precision of slitting rolling can be improved by 5%-6%, because the two lines bite in at the same time after slitting, the cross section changes little, and the temperature difference between head and tail is small and the load is uniform. In addition, slitting rolling is only carried out in the last three stands, and the rest are micro-tension and tension-free rolling.

When the rolling mill produces products of the same specification with billets of the same size, only 1/2 of the cross section needs to be rolled, thus reducing rolling passes. At the same time, double-wire or multi-wire rolling can be realized, which greatly increases the output of the rolling mill, which is especially important when producing small-sized products.