Dissimilar-thickness coating strip steel zinc layer control method

Abstract

The invention relates to a dissimilar-thickness coating strip steel zinc layer control method. The control method comprises the following steps of 1, preparing data; 2, judging the control mode to determine whether to execute the step 3 of precomputing the pressure in a dissimilar-thickness control mode or execute the step 4 of finely adjusting and controlling the pressure of an air knife; 3, precomputing the pressure in the dissimilar-thickness control mode, computing the pressure set value PT of the upper surface and the pressure set value PB of the lower surface of strip steel after transition of the specification of a coating to serve as the adjusted air knife pressure P1(t+1) of the upper surface and the adjusted air knife pressure P2(t+1) of the lower surface of the strip steel correspondingly, and then executing the step 5; 4, finely adjusting the air knife pressure of the upper surface and the lower surface of the strip steel; and 5, controlling the thickness of the coating according to the adjusted air knife pressure of the upper surface and the lower surface of the strip steel, and then going back to execute the step 1. In the whole process, the dissimilar-thickness coating strip steel zinc layer control method has the advantages that the method has the good real-time performance on the control condition of a target value, fluctuation of the product quality is small,and careless omission or objections about large-area quality is not likely to occur.

Description

technical field [0001] The invention relates to a zinc layer control method for a differentially thick coated strip steel, which belongs to the technical field of hot-dip galvanizing. Background technique [0002] In the production process control of the hot-dip galvanizing unit, the thickness control of the zinc layer is a very important part, which is divided into equal-thickness coating control and differential-thickness coating control. The quality of coating control directly affects product quality and production cost. Too thick coating not only wastes raw material zinc ingots, resulting in waste of production costs, but also affects product welding performance, coating adhesion, coating anti-powdering performance, etc. If the coating is too thin, the corrosion resistance of the product will be reduced, which is unacceptable to users. [0003] At present, most domestic steel mills mainly rely on the experience of operators to manually set the air knife distance and air...

AI Technical Summary

Problems solved by technology

[0005] To sum up, none of the existing coating thickness control methods involves automatic control methods for products with differential thickness coatings, and the control methods either use neural network prediction methods or use The least square method describes the relationship between the control variable and the target value of the equal-thickness coating products, and the control of the target value has a large hysteresis in the whole process of unit production