A zinc layer control method for differential thickness coated steel strip

Abstract

The invention relates to a zinc layer control method for differential thickness coated strip steel, comprising the following steps: step 1, preparing data, step 2, judging the control mode, so as to determine whether to perform step 3 to pre-calculate the pressure under the differential thickness control mode , or execute step 4 to fine-tune the pressure of the air knife; step 3, pre-calculate the pressure in the differential thickness control mode, and calculate the pressure setting value PT on the upper surface of the strip and the pressure setting value on the lower surface of the strip after the coating specification transition occurs PB, respectively as the air knife pressure P1 (t+1) on the upper surface of the strip after adjustment and the air knife pressure P2 (t+1) on the lower surface of the strip, then perform step five; The pressure of the air knife on the lower surface; step 5, control the coating thickness with the adjusted air knife pressure on the upper and lower surfaces of the steel strip, and then return to step 1. The present invention has good real-time performance on the control of the target value in the whole process, and the fluctuation of product quality is small, and it is not easy to cause omissions or large-scale quality objections.

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