| 摘要 |
PURPOSE: A method for cooling the casting piece of stainless alloy in a nonmagnetic austenite group is provided to produce a casting piece in a continuous casting method for preventing cracks or defect generated while hot rolling while producing the stainless alloy in the continuous casting method. CONSTITUTION: A cooling speed of the area containing a liquid phase and a solid phase of austenite stainless alloy casting piece is controlled for 10-3000°C/min while controlling the cooling speed of the area from the solid phase to 700°C for under 150°C/min. Moreover, the solidification process or the segregation movement of austenite stainless steel is seized for preventing crack on the surface of the casting piece and the crack in a hot rolling. An austenite group phase(2) is generated at a liquid phase temperature(1) for being grown according the lowering of the temperature. Thus, the austenite group phase is collided with solidification structure. Then, solute elements such as Cr, Ni, Mn, Si, P, and S, which are discharged to liquid phase, are locked in a weak phase(3) remained in an inter-dendrite. The solidification is progressed for accumulating the solute elements. Then, the austenite phase becomes coarse by passing through a coarsening process. If the cooling speed from the liquid phase temperature to the solid phase temperature is lowered, the generation of solidification crack is prevented.
|
