Specimens of AISI 321 stainless steel (0Cr18Ni9Ti) of various martensile contents were prepared by the low temperature(-70℃) elongation method- X-ray diffraction (XRD) and transmission electron micrograph (TEM) techn...Specimens of AISI 321 stainless steel (0Cr18Ni9Ti) of various martensile contents were prepared by the low temperature(-70℃) elongation method- X-ray diffraction (XRD) and transmission electron micrograph (TEM) techniques were used to study the phase transition process and its structure. The relationship between deformation-induced martensite and stress corrosion cracking (SCC) susceptibility of the steel in 42% (boiling) MgCl2 solution was investigated using the constant load SCC test with the normalized threshold values. The results reveal that when the α'-martensite content is less than 5% and also in the range of 15%-24 % , the SCC susceptibility of this material decreases with the increase of α'-martensite content.However. whenthe α' martensite content is in the rang of 5% -15% and more than 24%, the SCC susceptibility of this material increases with the increase of the α'-martensite content. The SCC fracture surface of the specimens exhibits a stepped fracture surface and transgranular stress corrosion fracture surface morphology.展开更多
基金Supported by the National Natural Science Foundation of China and State Key Laboratory for Corrosion and Protection and Study Foundation of The Hong Kong Polytechnic University.
文摘Specimens of AISI 321 stainless steel (0Cr18Ni9Ti) of various martensile contents were prepared by the low temperature(-70℃) elongation method- X-ray diffraction (XRD) and transmission electron micrograph (TEM) techniques were used to study the phase transition process and its structure. The relationship between deformation-induced martensite and stress corrosion cracking (SCC) susceptibility of the steel in 42% (boiling) MgCl2 solution was investigated using the constant load SCC test with the normalized threshold values. The results reveal that when the α'-martensite content is less than 5% and also in the range of 15%-24 % , the SCC susceptibility of this material decreases with the increase of α'-martensite content.However. whenthe α' martensite content is in the rang of 5% -15% and more than 24%, the SCC susceptibility of this material increases with the increase of the α'-martensite content. The SCC fracture surface of the specimens exhibits a stepped fracture surface and transgranular stress corrosion fracture surface morphology.