Study On Forcasting Of Continuous Casting Roller Based On Image Processing Of Crack Network Simplified Theory

In the continuous casting process,the rollers will inevitably generate the problem of thermal fatigue,wearing and so on.In order to gain more benefits,we consider to adopt welding repair technology to repair the damaged rollers.Many cracks on the roller surface lead to large amount of the expansion depth and need to lathe the roller shell deeply which wastes the material of rollers and extends the processing time.Balancing fully using the residual life of rollers and repairing offline timely,it needs to calculate the life of the rollers to predict the proper time to tape out.The thermal crack on the roller surface coming from the cycle thermal stress is the main factor which decides the online time o f the roller.Due to a specific situation,the paper analyses the roller and gets the thermal field and stress field.Combined with the actual working condition of the roller,get the conclusion that the crack type is mode-I crack.The paper analyses influencing factors,such as the inner pressure,the tension,the bending moment,and the dynamic load effect,contributes to the stress intension factors(SIF)in crack tip area.Using the SIF as a reference variable and combined with real working condition,the paper choose the merging law of the cracks on the roller surface comparing different merging laws.Adopting the MRF and ICM simulation,separates the cracks and non-cracks mixed in the picture.Comparing the pixels in the transverse and longitudinal directions,choose the length of crack as the observational variable combined with the force condition of the roller.Using the software FRANC3 D and selecting the different shape and different relative location as variables analyses the influence on the main crack and gets the crack leading front propagation law.Combined with the results of crack network simplification,the paper proposes simplification rules and determines the priorities.Adopting the linear superposition principle to calculate the influenc e of multi-cracks on the main crack and using the crack shape of b/a=0.3 as an example fits the SIF formula of main crack propagation front.Finally,comparing the real quantity of steel passing through a mould and the simulation,the paper testifies the the network simplification theory of using crack shape as a bridge and the crack length as a variable.