Stability condition of semisolid continuous casting process

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Stability condition of semisolid continuous casting process

The major unsteady phenomena in semisolid continuous casting process are the breakage and breakout. The essential reasons for them are the passageway blocking or the solidified shell too thin to endure the withdrawal force because of the remained shell formed at the beginning and its developing afterwards. Through theoretically analyzing the crack filling and the remained shell developing, stability conditions were presented. The essential one of them is that the stress acted on the semisolid slurry must be larger than the yield stress of it. The condition without breakage is to build a balance between the increase of the remained shell resulted in solidifying and the decrease of it resulted in flowing of the semisolid slurry. The condition without breakout is to ensure the solidified thickness larger than the safe thickness. The corresponding mathematical formulas of these conditions were set up and the verification experiments show that these conditions are reliable in applications.