| Because of the special compositions and solidification characteristics of37Mn5,there are many difference between carbon steel casting and37Mn5casting for the choiceof mold fluxes. Ever the surface crack quality problem of37Mn5steel was serious inTiangang united special steel co.ltd. In order to solve this problem, the solidificationcharacteristics of37Mn5steel and round billet was researched, Distribution temperatureof slag pool was simulated by ANSYS software, the relationship between mold fluxesand each component was researched. The current mold fluxes was optimized, and therang of physical chemistry properties of mold fluxes and percentage of each component.It was concluded that:1)37Mn5steel is crack sensitive grades will have the peritectic reaction in theprocess of solidification, shrinkage coefficient is4.5×10-5∕℃. The shell solidificationshrinkage volume and crack sensitivity. The air gap is big after round billet solidificationshrinkage, the heat transfer is uneven of billet, make the billet surface occure crack. Souniform cooling is important in37Mn5steel continuous casting.2) The physical chemistry properties of mold fluxes was researched, the meltingtemperature is1142℃, melting speed is84s, viscosity is0.532Pa·s, crystallizationtemperature is1270℃,it can’t effectively meet the demand of37Mn5steel continuouscasting.3) Distribution temperature of slag pool was simulated by ANSYS software, it wasfound that the thickness of liquid slag layer is12.8mm in slag pool, can effectively meetthe demand. The relationship between superheat and the thickness of liquid slag layer isweak, but it close to the melting temperature. the length of liquid slag betweencrystallizer and billet is only47.56％of the effective length, can’t meet the demand ofbillet lubrication.4) Designed the orthogonal experiment scheme. Research the relationship betweeneach component and melting temperature, viscosity, crystallization temperature,transition temperature.5) Under the existing process conditions, the properties rang of mold fluxes issuitable for37Mn5steel round billet, confirmed the melting temperature was less than1142℃, the melting speed was60～70s, the viscosity was0.55～0.70Pa·s and thecrystallization temperature was1100℃. Finally, combining the experimental results, thebest choice is the12#mold flux. |
