Controlling transverse cracks of slab based on edge control technology

Abstract

With the wide application of the micro alloy technology in recent years, the problem of slab surface transverse crack has become more severe. Based on the analysis of the J steelworks’ X80 steel slab transverse crack defects and the forming factors, the effect of slab edge control technology on transversal cracks was studied by numerical simulation. The results show that under the current wide-scope water spraying for 1 600 mm slab section size, the slab transverse temperature gradient was very high. Therefore, the temperature of the slab straightening segment could not avoid the third brittle zone completely, leading to frequent transverse cracks. To solve the problem, an optimization scheme of middle-scope water spray was proposed. After the optimization, the slab surface temperatures became more uniform, and the slab temperatures of the straightening segment increased than the third brittle zone, thus reducing the transverse cracks effectively. By changing the water spraying scope and cooling water volume, the edge control technology achieved the expected edge and corner temperatures, solved the problem of slab transverse cracks, and improved the slab quality.