Modeling and simulation of quality analysis of internal cracks based on FTA in continuos casting billet

To improve the internal quality of the continuous casting billet, one new approach for quality analysis and optimum control is proposed based on fault tree analysis (FTA). The interrelation between different hypotheses of the formation mechanism of internal cracks is studied to find out the root causes. According to the features of FTA and expertise, a FTA model of internal cracks is developed, then the software VC++6.0 is introduced to form the visual-FTA system, which is available to generate and analyze the fault tree automatically. Applying the analysis system to the steel Q235 supplied by a steel-maker, the qualitative analysis/quantitative results basically conform to the on-line statistical ones, and then an optimum control scheme is proposed to improve the billet quality.