Wang, Yongqiang Li, Na Effect of Ferrite on the Precipitation of σ Phase in Cast Austenitic Stainless Steel Used for Primary Coolant Pipes of Nuclear Power Plants <div><p>The effect of ferrite phase on the precipitation of σ phase in a Z3CN20.09M cast austenitic stainless steel (CASS) used for primary coolant pipes of pressurized water reactor (PWR) nuclear power plants was investigated by using isothermal heat-treatment, optical microscopy (OM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) techniques. The influence of different morphologies and volume fractions of ferrite in the σ phase formation mechanism was discussed. The amount of σ phase precipitated in all specimens with different microstructures increased with increasing of aging time, however, the precipitation rate is significant different. The formation of σ phase in specimens with the coarsest ferrite and the dispersively smallest ferrite is slowest. The lowest level Cr content in ferrite and fewest α/γ interfaces in specimen are the main reasons for the slowest σ precipitation due to they are unfavorable for the kinetics and thermodynamics of phase transformation respectively. By contraries, the fastest formation of σ phase takes place in specimens with narrow and long ferrite due to the most α/γ interfaces and higher Cr content in ferrite which are beneficial for preferential nucleation and formation thermodynamics of σ phase.</p></div> Cast austenitic stainless steel;ferrite;σ phase;precipitation behavior;microstructure 2017-12-05
    https://scielo.figshare.com/articles/dataset/Effect_of_Ferrite_on_the_Precipitation_of_Phase_in_Cast_Austenitic_Stainless_Steel_Used_for_Primary_Coolant_Pipes_of_Nuclear_Power_Plants/5668975
10.6084/m9.figshare.5668975.v1