Analysis And Control Of Abnormal Spinning Of High Speed Wire Rod

In recent years, with the improvement of the equipment level of high-speed wire rod mill, its maximum finishing speed has reached more than 112m / s, and the product specification has been expanded to Ф 5mm- Ф 25mm。The improvement of rolling speed and the limitation of wire rod size make it more difficult to control wire drawing, which often affects the production efficiency and product quality. In production, there are often steel hanging at the head and tail, disordered wire drawing circle, abnormal phenomenon of steel blocking and wire drawing, as well as quality defects such as indentation and scratch, which become the bottleneck to improve the unit operation efficiency and product quality. Therefore, the abnormal spinning problem is analyzed and solved.

Abnormal spinning and its cause analysis

Due to the influence of changes in size, steel grade and finished product speed, the spinning conditions of wire rods of different specifications are very different. The problems of steel hanging at the tail, disordered wire loop shape and unstable falling position are easy to occur in general small-sized wire rod; Large size wire rod is prone to the problems of small drawing, high stacking and steel blocking.

In order to reduce the forward resistance and ensure stable rolling, it is set that the head and tail of the wire rod do not pass through water in the water-cooling box, so the head and tail of the wire rod are relatively soft after wire drawing, and steel hanging accidents are easy to occur on the roller table at the inlet of stellmore line and on the cooling line; The disordered spinning mainly refers to the phenomenon of poor spinning circle shape, disordered circles (commonly known as inverted inserting material) and erratic falling position of coils in the production of small-sized wire rod. The disordered wire drawing will cause problems such as steel hanging of stellmore wire, steel blocking of collecting drum, difficult finishing and poor product quality, as well as accidents such as uncoiling ferrule and wire breaking during wire deep processing.

Solutions

Reasonably set the positioning accuracy of the head of the spinner, and timely adjust the positioning parameters through the main control room according to the production conditions; Check the wear, deformation degree and clearance of the roller at the entrance section of styrmo line, and timely replace the roller when it is deformed or the clearance increases. Check and correctly set the tail speed drop coefficient of reducing sizing machine, pinch roll and laying head to make the wire drawing at the tail of rolled piece stable; Correctly set the pinch roll function, clamping force, closing roll gap and other parameters; Check the working condition of the cylinder and the clamping groove, and replace the cylinder leakage and excessive wear of the clamping groove in time.

Through the analysis of the causes of various abnormal phenomena in the threading area and the adoption of the above measures, the current threading operation effect has been significantly improved, the threading ring shape of all specifications of products is uniform and stable, various accidents such as steel hanging at the head and tail, disordered ring shape, steel blocking in coils, indentation, scratch and so on have been effectively controlled, and the unit operation rate and yield have been greatly improved. However, there are still some problems to be solved in the production of large-scale low-temperature spinning alloy steel by hot mechanical rolling process.