Study on final solidification point of continuous casting Q345 Steel wide slab

A solidification heat transfer mathematical model of wide slab is established based on practical production conditions of Q345 steel wide slab in Echeng Steelmaking plant to determine final solidification point.Besides,it is tested and modified by pin-shooting technique.The results show that the relative error between the results measured by pin-shooting technique and the results calculated by solidification heat transfer mathematical model is within 1.3 %,so the results calculated by solidification heat transfer mathematical model can reflect final solidification point of Q345 steel wide slab truthfully.In typical speed of 1.15 m/min,the mushy zone of 200 mm thickness wide slab is 13.32~20.95 m far from mold liquid level.In typical speed of 0.95 m/min,the mushy zone of 250 mm thickness wide slab is 16.16~23.45 m far from mold liquid level.In typical speed of 0.80 m/min,the mushy zone of 300 mm thickness wide slab is 19.34~27.65 m far from mold liquid level.The final solidification point is very different at different casting speed and slab thickness.After continuous casting process optimization the qualified percentage for central segregation in Q345 steel wide slab within rating I increases from 85.4 % to 99.5 %.