Causes of cracks on the surface of continuous casting slab1.The main cause of longitudinal crack is too high molten steel temperature or too fast drawing speed.
Causes of cracks on the surface of continuous casting slab
1.The main cause of longitudinal crack is too high molten steel temperature or too fast drawing speed. Because it is difficult to make the mold cool evenly, the stress is always large or small. When the temperature of molten steel is high, the billet shell is thin and the strength is low. Small stress will tear the billet shell and cause longitudinal crack. High drawing speed is the same as high temperature.
2.The tundish nozzle and crystallizer fitting nozzle are misaligned or the casting nozzle is deformed, and the steel flow is offset. On the side close to the steel flow, the growth of the billet shell slows down, the billet shell thins, resulting in cracks, and even the phenomenon of steel leakage caused by the direct scouring of the billet shell by the steel flow.
3.Insufficient cooling water of crystallizer accessories, low flow rate of water gap, local boiling of cooling water or uneven distribution of water flow in water jacket will cause uneven cooling and cause cracks.
4.The use time of crystal accessories is too long, and the copper pipe is seriously damaged, worn and deformed. In particular, the inverted taper becomes smaller, the air gap between shell and wall increases, the heat transfer is blocked, and cracks are easy to occur.
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Harm of too high temperature: when molten steel out of cooper mold, the billet shell is thin and easy to break out; The accelerated erosion of refractory can ea
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1. The barrier function (mainly completed by the liquid slag layer) isolates the contact between air and molten steel, blocks the secondary oxidation of molten
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In continuous casting, low corrosion resistance often occurs, which directly leads to uneven composition and will eventually affect the smelting quality. In or