Cause Analysis of the Oxide Scale Formed in Furnace for W470 Steel

The oxide scale formed in furnace for W470 steel was difficult to remove,and seriously affected the surface quality of the finished product.The surface morphology and phase structure were investigated by SEM,EDX,XRD.The results showed that the oxide scale on W470 steel consisted of both oxide scales of the outer latey to be easily removed and the inner layer to be difficult to remove,and both oxide scales all included Fe 2 SiO 4.FeO and Fe 2 SiO 4 were wrapped up in the inner oxide scale each other,and tightly band together with the matrix.The silicon element was preferentially concentrated at the interface in matrix to forme a large number of the rich silicon oxide.Rich silicon oxide greatly reduced the oxidation rate of steel,the difference of oxidation rate made the steel surface form the uneven oxid scale.