The reason of thickness difference of cold rolled steel strip

(1) Cold rolling process reasons

Cold rolled steel strip manufacturers believe that the disturbance of cold rolling machine itself belongs to this category: under different speed and pressure conditions, the oil film thickness of oil film bearing will be different (especially the change of oil film thickness when acceleration and deceleration); Radial ellipticity (roll eccentricity); Roll thermal expansion and roll wear. Roll eccentricity is a kind of high frequency interference.

(2) Reasons for abnormal cold rolling production

Cold rolled steel strip manufacturers believe that other reasons caused by the thickness of the difference, such as technology, belong to this category: under different speed conditions of roll and workpiece rolling emulsion is different, rolling friction coefficient is different (including friction coefficient fluctuation during acceleration and deceleration); Continuous cold rolling or pickle-cold rolling units require dynamic specification changes in the process, resulting in a wedge-shaped transition: the difference in thickness of the pickle-washed or rolled weld as it passes through the mill. This thickness difference is abnormal thickness difference, not cold rolling AGC can solve, is inevitable. The fluctuation of incoming material thickness and hardness will cause the change of rolling force, and the rolling mill bounce will affect the thickness, while the disturbance of the rolling mill itself will affect the thickness mainly by changing the actual roll gap value (the signal of the roll gap meter will not change), so different control strategies are needed. Due to the thinness and work hardening of continuous cold rolling, the ability to correct the thickness difference is limited, and high quality hot rolling incoming material is an important condition for the production of high quality cold rolling products.

Cold-rolled steel strip manufacturers believe that mechanical properties refer to the mechanical properties of the material under various external loads (tensile, compression, bending, torsion, impact, alternating stress, etc.). Under different environments (temperature, medium, humidity), the mechanical properties of strip steel refer to the indicators reflected by external forces, including tensile strength, yield strength, elongation, area shrinkage, impact toughness, etc.

Post time: Apr-14-2023