The Optimization Of Cooling Process Of Slab Continuous Casting In Straightening Zone

Based on production process of slab continuous casting in the Tang Shan Gang Lu Iron&Steel,represented by typical steel of Q345?SPHC?Q235,combined with field test and mathematical simulation,worked out the temperature of slab's cross section under different process parameters,the effect of the secondary cooling intensity,casting speed,slab width to slab's surface temperature in straightening zone have been analyzed,and based on the relationship between straightening crack and slab's surface temperature,the production process of the Q345 slab have been optimized.The results are shown as follows:1)Under the current process,lowering secondary cooling intensity,increase the casting speed or increasing the superheat could also raise the surface temperature of the slab in straightening zone;but the change of slab width didn't affect the slab's surface temperature in straightening zone.2)The every one level below of the secondary cooling intensity from strong cold to more weaker cold,the temperature of surface center or corner would risen 8.9?17.2? or 7.3-17.4?.3)The casting speed increased 0.1 m/min in the range of 1.2m/min to 1.6m/min,under the more weaker cold,the temperature of surface center or corner would risen 5.9?12.9? or 12.3?24.1 ?;under the strong cold,the temperature of surface center or corner would risen 1.3?6.2? or 8.5?20.9?.4)Affected by the slab's temperature in straightening zone,the slab from Gang Lu have serious surface transverse cracks,under the current cooling condition,in order to avoid surface transverse cracks,it should meet:under the weak cold,the casting speed should be not less than 1.6m/min;under the more weaker cold,the casting speed should be not less than 1.5m/min.