Effect of Solid Solution Temperature on Microstructure and Corrosion Resistance of CoNiCrMo Alloy

Influence of solid solution temperature on microstructures and corrosion properties of CoNiCrMo alloy were investigated by means of optical microscopy (OM), scanning electron microscope (SEM) and electronic differential system. The corrosion resistance of CoNiCrMo alloy in 0.9%NaCl aqueous solution was also investigated. The results indicated that with the increase of solution treatment temperature, the dendrites of CoNiCrMo alloy gradually disappeared. Thus, the corrosion resistance of the alloy decreased. When the solution temperature is 1200oC, the dendrites almost disappeared and most carbide dissolved, and begins to spheroidization. The corrosion resistance of CoNiCrMo alloy treated at 1000oC for 1h is the highest than the one at 1100 oC and 1200oC. Its self-corrosion potential is -424mV and self-corrosion current density is 1.02×10-8A/cm2.