Cast structure is easy to produce castings of more serious TXC segregation, unequal organization, such as the casting surface section is often fine equiaxed, columnar grain floor, the middle is equiaxed and Widmanstaten and mesh cementite, need be removed by heat treatment (solid-state recrystallization) or mitigate their harmful effects, steel castings to control the microstructure by heat treatment to achieve the desired properties. In addition, as the thickness of steel castings and the impact of differences in the structure of the same cast each part having different organizations and can generate considerable need to eliminate residual stress, therefore, generally cast steel valves are required to heat treatment delivery.