Research On Soft Reduction Control System In XinSteel 420mm Thick Slab Casting

With the continuous development and improvement of the slab casting technology, the method of using the solidification end soft reduction technology has effectively inhibit the center segregation and porosity. This method also guarantees the production of high-quality and high value-added slabs. More and more companies start to use the soft reduction technology widely. The technology has become the most effective ways to avoid center segregation and porosity, and it’s an important flag of the modern slab casting.This thesis analyzes the XinSteel 420mm slab casting status and field craft. As one of the key technologies of the slab casting, soft reduction system has a direct impact on the quality of slab. At present there is no heavy slab caster soft reduction related experience, technical information or process parameters. In order to effectively protect the quality of slab, the system’s validity must be ensured.Several typical thickness steel slabs were selected in the production process of slab casting. Shell thickness of slab were measured and integrated coagulation factors were corrected through the nail experiments, and defined the depressed position under the different kinds of steel and different thickness. Nailing experiments can track slab solidification process more accurately, which provides more reliable information on solidification for soft reduction technology.A dynamic compensation method for servo valve’s zero drift was developed through high precision hydraulic roll gap control research, and using the simulation to analyze the effects of zero drift compensation algorithm. Based on the relationship between the measured values and the roll gap displacement sensor in the hydraulic system debugging, the hydraulic cylinder rigid curve and rack-optimized calibration force was calculated, as well as the mechanical deformation compensation algorithm. After the introduction of the above algorithm, the original slab casting soft reduction system on the dynamic response speed was improved and the slab casting soft reduction control system response speed and accuracy were improved as well.After production practice test, the result shows that the automatic control system with variety of soft reduction compensation algorithm can effectively improve the quality of slabs. It also plays an important role in promoting the company’s product structure adjustment and upgrading.