Monoblock Mill (wire rod mills) raw material is commonly used (120 mm x 120 mm) – (160 mm x 160 mm) with a length of 6 – 24 M.
The following factors must be taken into account in determining the section size of billet:
A. Keep the metal flow rate of each rolling pass equal under the condition of full continuous rolling. The first rolling mill’s tapping speed is not less than 0.1m/s or the first rolling mill’s tapping speed is not less than 0.07m/s. Otherwise, because of the low rolling speed, the contact time between the roll and the workpiece in the deformation zone is too long, the roll is heated sharply, and after turning the deformation zone. When the cooling water drops sharply, the thermal stress of the roll will lead to fatigue cracking or even block falling of the groove metal. Rolling speed, disk weight, and billet section are three basic parameters of high-speed wire rod mill (monoblock mill). In continuous wire rod rolling mill (monoblock mill), when the rolling speed of the first stand is not less than 0.1m/s, the maximum cross-section of raw material is determined by the total elongation coefficient after the final product specification and rolling speed are determined.
B. In the discontinuous rolling mill, the temperature before entering the finishing mill and the temperature difference between the end and end of the imported finishing mill (monoblock mill) are the conditions that must be considered when choosing the billet. Over shuttle rolling and large loopers for small pieces are not desirable.
C. When the section of continuous casting slab of carbon structural steel and low carbon alloy steel is less than 120 mm *120 mm, the casting speed is too fast and the leakage rate increases and the periodic segregation of non-metallic inclusions in the center of continuous casting slab are serious. When the section of continuous casting slab of high-quality carbon steel and low carbon alloy steel is less than 150 mm *150 mm, the closed casting cannot be realized and the steel flow is heavy. Dew produces secondary oxidation in air, which results in poor chemical stability.
