historical background
In the middle of the 20th century, due to the war and post-war reconstruction, industrial countries needed a large number of wire rods. This has promoted the rapid development of wire rod rolling mill.
In the mid-1960s, the advent of high-speed non-twist wire rod finishing mill pushed the world wire rod production technology to a new stage. After that, the equipment level and rolling technology of wire rod mill have changed fundamentally and the high-speed non-twist mill has become the mainstream of wire rod production.
High-speed wire rod mill has the advantages of high rolling speed, high product accuracy, good surface quality and significant rolling plate. At the same time, it has the characteristics of no torsion and slight tension in the whole rolling line. High-speed wire rod mill is composed of roughing mill, intermediate mill, pre-finishing mill and finishing mill. Generally, the whole rolling line includes 28~30 mills.
Roughing mill roll
Roughing mill is generally composed of 4~8 stands. Due to high starting temperature, large section and deep roll groove. Therefore, the roll used for roughing stand should have good anti-breaking, anti-hot crack, anti-wear performance and good bite performance. Generally, the rough rolling stand adopts pearlitic nodular cast iron roll with hardness of HSD 45-55 or alloy semi-steel roll with hardness of HSD 45-50.
Intermediate mill roll
The rolls of the intermediate rolling mill are generally required to have good wear resistance and surface roughness resistance. There is not much difference in material selection. Therefore, the rolling unit in high-speed wire rod mill generally selects pearlitic nodular cast iron roll with hardness of HSD 60~70 or Alloy Infinite chilled cast iron roll, which is both economical and practical.
Pre-finishing mill roll
The high speed wire rod mill has a wide selection of materials for the roll ring of the pre-finishing mill. Some manufacturers use tungsten carbide hard alloy roller rings, which have good wear resistance but low strength, and may also break. The strength of centrifugal composite ring and high-speed steel rolling is higher and the price is lower than that of tungsten carbide roll ring. Therefore, centrifugal composite roll ring and high-speed steel roll will be the preferred materials for the roll or roll ring of the pre-finishing mill in the future.
Wire rod finishing mill roll
The finishing mill of high speed wire rod mill is an important factor to ensure high precision rolling of wire rod. Therefore, tungsten carbide roll rings must be used in the finishing mill of high-speed wire rod mill. Otherwise, the rolling speed and the wear resistance of the roll ring cannot be guaranteed. Up to now, there is no such material to replace the tungsten carbide roll ring of the finishing mill of high-speed wire rod mill.
