Practice of Controlling the Cleanliness of Q390C Steel Under low Alkalinity Refining Slag
A study was conducted on the cleanliness of molten steel under low alkalinity refining slag for Q390C steel plate.The results showed that the slag system component w(CaO)=43%~48%;w(SiO2)=12%~l5%;w(Al2O3)=23%~27%;w(MgO)is 3%~7%.When alkalinity(CaO/SiO2)is 3~4,the slag is completely in the liquid phase,and w[S]≤ 0.008%,w(T.[0])≤0.002 5%,the level of BT and Ds inclusions is reduced,and the cleanliness of the molten steel meets the requirements.