Differential scanning calorimetry analysis on Cu precipitation in a high Cu austenitic stainless steel

The Cu precipitation in a high Cu austenitic antibacterial stainless steel (3.8–5.0% Cu) was studied by using differential scanning calorimetry (DSC) analysis. The results indicated that DSC analysis could be used to detect the Cu precipitation in the experimental steel with different Cu additions. Two stages of precipitation were identified in the steel by DSC analysis, clustering of Cu-rich phases and dissolution/coarsening of the precipitates formed at the first stage. DSC analyses also showed that with increase of the Cu content in the steel, the start temperature of Cu precipitation was decreased and the peak area of Cu precipitation was enlarged. The activation energy for Cu precipitation in the steel was determined to be 181 kJ/mol, indicating that the process should be mainly related to the diffusion of Cu atoms in the steel.