论文部分内容阅读
Evolution and growth of non-metallic inclusions are very important phenomena to understand the role of inclusions on the formation of microstructure of steel.Formation and stability of inclusions in steelmaking temperature or solidification temperature have been studied in detail to control the composition and size of inclusions.However,when we aim to utilize existing inclusions for the creation of microstructure of steel,evolution or growth of inclusions in solid steel is also quite significant.Recently,the evolution or growth of inclusions in solid state steel has been intensively studied by several researchers and the evolutional change of inclusions has been reported.In the present study,the evolution and growth of inclusions in solid iron deoxidized by Al-Ti addition have been studied.Two Fe-AI-Ti alloys were prepared with difference nitrogen content at I 873 K.A cylindrical piece of the alloy was machined and the piece was encapsulated into a steel ampoule by arc-welding.The ampoule was heated at 1 473 K for 3 h,and then inclusions in the as-cast and heated specimens were observed and analyzed by FE-SEM and EDS.The equilibrium oxide at 1 473 K was defined by the composition change of Al2O3-TiOx inclusion during heating.Size and number of Al2O3-TiN inclusions increased by formation and growth of TiN during heating.Increase in N content resulted in the enhancement of TiN formation.