Preparation Of MgO-containing Corundum-Spinel Castables And Modelling Of Corrosion Induced By Fluid Dynamics And Optimization

With the requirement for steel cleanliness and development of steelmaking technology,liquid steel cleanliness requirements increase,corundum spinel castable has become the main refractory for ladle.However,introduction of spinel has an important effect on properties of the castable.In this paper,the molten steel flow fields and slag entrapment during casting were numerically simulated,the flow induced corrosion was anlyzed,then flow fields were optimized.The properties and structure of MgO-containing corundum spinel castable of which tabular corundum aggregate was replaced by the MgO 4wt%corundum aggregate were studied.The main conclusions are as follows:?1?During ladle casting process,mixing region which height is 60mm of molten steel and slag appears.In this mixing region,refractories are severely damaged because of flow induced erosion.The height of the mixing region decreases by 50%when the right angle dam is established in the ladle.And the erosion area of refractoryis effectively reduced.?2?After 1000?×3h treatment,the results show that the room temperature flexural strength of castable increased by 39.7%,and the room temperature compressive strength of castable increased by 84.4%with the addition of Mg-containing corundum increased from 0wt%to 75wt%.After 1500?×3h treatment,the room temperature flexural strength of castable increased by 92.4%,and the room temperature compressive strength of castable increased by 74.2%.After being heated at 1500?for 3h,the strength retention rate increased from 15%to 23%after five times of 1100?-water cooling cycle.After 1600?×3h slag resistance test,penetration area of the castable decreased from 20.6%to 15.6%,eroded area of the castable decreased from 6.2%to 1.3%.?3?After 1500?×3h treatment,with the addition of MgO-containing corundum increased,the addition of magnesite decreased,combination between aggregates and matrix in castable was improved,the compressive strength at room temperature increased.After 1500?×3h treatment,the alumina rich spinel gathered in pores and edges of aggregate,and the content of Al₂O₃ in the aluminum rich spinel increased which was easy capturing Fe and Mn in the slag.The spinel introduced by the aggregate dispersed more evenly in the castable.When the temperature gradient occurs inside the material,the differences of the thermal expansion coefficient decrease,as results,the thermal stress will decrease and the thermal shock resistance of the material increases.