How does the white iron appear in the case of ductile iron?
The addition of 0.2% SiC in the raw iron water can effectively reduce the chill.
If it is to solve the white cast, the casting can be annealed.To prevent a chill in the casting, it is important to know your entire casting process to find the cause and the solution.
Casting cooling, surface and thin section at often produce white. White tissue hard and brittle, poor processing performance, easy peeling. So it is necessary to use the annealing (or normalizing) method to eliminate white tissue. The annealing process: heating to 2 DEG C 550950 ~ 5 h, then 500 to 550 DEG C Furnace cooling again followed by air cooling. During high temperature insulation, high travel cementite eutectic cementite decomposition of graphite and A in the subsequent two carburizing cooling process and eutectoid cementite decomposition, graphitization process. Due to the decomposition of cementite, resulting in the decrease in hardness, thereby improving machinability.Hope to help you.
