There are many serious problems are directly associated with the flow pattern in the mold in the continuous casting of steel process. The nozzle flow plays an important role in determining the mold flow pattern and to minimize casting defects. In this work a new type nozzle designed for a slab casting mold is developed. The 3-D steady k-ε finite-volume model has been applied to study the turbulent flow in nozzle and mold, which predict velocities agree with the impeller measurements in the water model well. The results show that nozzles with a mountain bottom are more impressionable to problems from asymmetric flow and large fluctuation on the mold surface. The impact of liquid at wave bottom nozzle can suppress the jet flow effectively and reduce the velocity variation.

Drastic flatness changes in high-strength steel strips during water quenching cause problems for both their subsequent manufacture and final products. In this work, a temperature-microstructure-stress coupled finite element model is established to simulate the quenching process of cold-rolled high-strength steel strips using a UMAT subroutine in ABAQUS. The evolution mechanisms of two main forms of flatness defects, including C warping defect and edge wave defect, are investigated. Our simulations reveal that the temperature gradients of the strips induce their extension differences along transversal/thickness direction and the sequential phase transformation, both of which finally cause the flatness changes. Furthermore, flatness control strategies are proposed according to the integrated effects of the tension and initial temperature differences during quenching. In addition, quenching experiments are implemented to validate the numerical results.

The elongation closed-loop control mode is essential for the temper rolling of the ultra-thin tin plate. During an unsteady process, the interstand tension is used for the stabilization of the elongation. But due to the drastic changes of the rolling force and rolling speed, the elongation fluctuation is beyond the tension control, which leads to the flatness degradation. In order to stabilize the elongation and the flatness, the adaptive compensation control for rolling force during the unsteady process is discussed in this work. This gain compensation for rolling force is based on the theoretical results from the rolling force model and validated from experimental results. Industrial experiments and application show the fluctuation of the elongation reduces by 90.11% during the unsteady process. Meanwhile, the change range of interstand tension reduces from 14% to less than 5%, length of the flatness degradation period decreases from over 180 m to shorter than 60 m.

Based on the slab caster mold of ChengGang Company as prototype, the water model with 1:1 scale was used to study the effects of casting speed、nozzle port angle、immersion depth、bottom structure、mold width and other parameters on the surface flow velocity of liquid steel in slab caster mold. The results show that the effect of casting speed is biggest and with increase in the casting speed, the surface flow velocity of liquid steel is prominently increased, when the mold width at 1650mm, the surface flow velocity from 0.04m/s to 0.1m/s with the casting speed from 0.7m/min increased to 1.4m/min

The fluid flow in the mould of slab continuous caster was investigated by 1:1 ratio water modeling simulation system. The effects of outlet angle of Bilateral and quadripuntal SEN on surface turbulence, penetration depth and surface velocity were discussed and the regularity of the flow field for change of outlet angle in slab continuous casting mould was obtained. The results show that the case C (both α and β are downward angle and α<β) is better than the usual SEN, for this kind of SEN can stabilize surface turbulence and reduce penetration depth and get moderate velocity.