Pitting Corrosion on H13 Hot Work Die Steel Surface

Pitting defect has been found on the surface of H13 hot work die steel during manufacturing.The defect was investigated in this study,and the initial position of corrosion induced by chloride ions was inspected by the acceleration test of soaking process in FeCl3 solution.The results show that the pitting defect on the surface was of pitting corrosion,and the corrosion product consisted of O and Cl.The initiation of pitting corrosion may take place on the interface of matrix with the second phase particles(such as Mo6C carbides),Al2O3 inclusion,eutectic carbides and so on.The formation of this kind of pitting corrosion may be associated with the local pit environment during the storage of the mold.