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.