COMPOSITE MATERIAL SHOWING SUPERIOR CORROSION RESISTANCE UNDER CHLORIDE-CONTAINING ENVIRONMENT

摘要

PURPOSE:To improve corrosion resistance under a chloride containing environment and erosion resistance by adding NbC to a matrix containing Ni and Cr and further containing, if necessary, Fe. CONSTITUTION:A composite material is constituted by dispersing a hard NbC powder by 1-72% by weight into a matrix of a corrosion-resisting metal consisting of a binary or ternary alloy of Ni(21-83%)-Cr(16-76%)-Fe(0-16%). This composite material forms a passivating film excellent in corrosion resistance, such as pitting corrosion resistance, stress corrosion cracking resistance, and intergranular corrosion resistance, under the environment containing chloride ions as the principal component of seawater. Further, by the presence of NbC grains, pitting corrosion resistance is improved and the effects, e.g., of preventing erosion even if subjected to the collisional action of fine solid matter, such as silica sand, can be produced.