Study On The Regularity Of Solidification Of316Stainless Steel In The Mould During The Continuous Casting

The volume shrinkages based on peritectic reaction bring the air gap between solidified shelland copper in continuous casting process of the peritectic steel. The air gap is the important factor ofunstable thermal conductivity, uneven growth of solidified shell,and will generate some defects.Therefore,it is fairly important to study the influence of the primary δ ferrite content.The paperinvestigates the influence of δ ferrite content, the casting speed, the superheat etc on the thicknessgrowth of shell in mould in316austenite stainless steel. depending on the commercial software-ANSYS and the thickness data of the breakout slab shell from Royal Institute of Technology,Sweden. Outlet temperature, surface temperature and thickness change of the solidified shell aresimulated as five different δ ferrite content,0%,25%,50%,75%and100%, four types of castingspeed,0.4m/min,0.5m/min,0.6m/min,0.8m/min, three different superheat,30℃,40℃and50℃, and three types of fluctuation cycle，50mm,75mm and100mm. Then the regularity of shellthickness evolution in the mould was discussed. Meanwhile, the result of simulation and thethickness of the breakouting of slab shell in the mould was compared to demonstrate the correctnessof the simulation.The results show that the contents of the δ ferrite have great effects on the gradient oftemperature along the casting direction，and is little effects on the lateral temperature variations.From the calculating results the shell thickness is the minimum in about40mm from the corner ofthe slab. Meanwhile，the thickness variations are investigated systematically;with the casting speedand superheat increased,the outlet and the corner temperature of slab shell rise,outlet thicknessbecome thin.The undulatory range of the corner temperature gets smaller with the casting speedincreased;the shell thickness is minimum about40mm on the horizontal with the low castingspeed,the location of the shell thickness approaches to the corner of shell with the high castingspeed.Under the calculation conditions of this paper,the other results also shows temperaturefluctuations can be over250℃in150mm along the horizontal of wide face and the maximum oftemperature fluctuations is87.44℃in100mm along the casting direction. Fluctuation cycle hassmall effect to,the outlet temperature and outlet thickness of shell. The experimental data ofthickness of shell display fluctuation change.The comparability of the thickness of the breakoutingof slab shell of Royal Institute of Technology, Sweden and the result of simulation which is50%ofδ ferrite content revealscorrectness of simulation. Result of simulation presented that δ ferrite content, casting speed,superheat and fluctuationcycle has different influence on the thickness of shell in the mould. This will offer the clews andproof for researching of the growth of solidified shell and improving heat transfer in the mould.