The effects of long-term annealing on the microstructure and pitting corrosion resistance of Fe_(balance)-18Cr-12Ni-1.5Mn-(0.2%,0.8%,1.8%,mass fraction)B stainless steels were investigated.For the B-containing stainle...The effects of long-term annealing on the microstructure and pitting corrosion resistance of Fe_(balance)-18Cr-12Ni-1.5Mn-(0.2%,0.8%,1.8%,mass fraction)B stainless steels were investigated.For the B-containing stainless steels,annealing at 1180℃for 192 h spheroidized the(Cr,Fe)_(2)B phase,increased the grain size,and homogenized the element distribution in theγmatrix around(Cr,Fe)_(2)B.Potentiodynamic polarization tests indicated that the long-term annealed samples had lower resistance to pitting corrosion than the unannealed samples,and MottSchottky analysis showed that the passive films formed on the annealed samples contained larger amount of point defects.In addition,the films on the annealed samples had a lower cation fraction of Cr than those on the unannealed samples.The changes in the pitting resistance and passive film properties were found to be primarily due to the grain growth during long-term annealing.展开更多
基金supported by the Korea Planning & Evaluation Institute of Industrial Technology under the Ministry of Trade,Industry and Energy (MOTIE, Korea, Program No: 20010778)Fundamental Research Program (Grant no. PKC2130) of the Korea Institute of Materials Science (KIMS) in 2024
文摘The effects of long-term annealing on the microstructure and pitting corrosion resistance of Fe_(balance)-18Cr-12Ni-1.5Mn-(0.2%,0.8%,1.8%,mass fraction)B stainless steels were investigated.For the B-containing stainless steels,annealing at 1180℃for 192 h spheroidized the(Cr,Fe)_(2)B phase,increased the grain size,and homogenized the element distribution in theγmatrix around(Cr,Fe)_(2)B.Potentiodynamic polarization tests indicated that the long-term annealed samples had lower resistance to pitting corrosion than the unannealed samples,and MottSchottky analysis showed that the passive films formed on the annealed samples contained larger amount of point defects.In addition,the films on the annealed samples had a lower cation fraction of Cr than those on the unannealed samples.The changes in the pitting resistance and passive film properties were found to be primarily due to the grain growth during long-term annealing.
