Erosion-Corrosion Behavior of Various Cast Iron Materials

Abstract

To obtain an effective metal material using valve, the erosion-corrosion behavior of various cast irons in flowing water was investigated. The erosion-corrosion of cast irons was affected by environmental factors, i.e., flowing velocity, temperature and dissolved oxygen content. The erosion-corrosion rate increased with increasing influence of environmental factors. The rate (V_e·c) exponentially increased against flowing velocity (v). The relation of V_e·c with v was described by the equation of Lotz & Heitz, i.e., V_e·c=bv^a, where, a and b are flowing velocity index and constant, respectively, and the a values are 0.8 in closed system and 0.4 in open system. In comparison with gray and austenitic cast irons, the austenitic cast iron has the more effective resistance of erosion-corrosion. The austenitic cast iron depressed local anodic reaction.