中南大学学报（英文版）
中南大學學報（英文版）
중남대학학보（영문판）
JOURNAL OF CENTRAL SOUTH UNIVERSITY OF TECHNOLOGY(ENGLISH EDITION)
2015年
7期
2423-2434
,共12页
丰雷%潘清林%韦莉莉%黄志其%刘志铭
豐雷%潘清林%韋莉莉%黃誌其%劉誌銘
봉뢰%반청림%위리리%황지기%류지명
aluminium%polarization%electrochemical impedance spectroscopy (EIS)%intergranular corrosion%exfoliation corrosion%stress corrosion
The through-thickness corrosion inhomogeneity of 7050-T7451 Al alloy thick plate was studied using immersion tests, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), slow strain rate testing (SSRT) technique combined with optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the through-thickness corrosion resistance is ranked in the order of T/2>surface>T/4. And the 75 mm-thick 7050 alloy plate presents better corrosion resistance than the 35 mm-thick plate. The results are discussed in terms of the combined effect of recrystallization and cooling rate in quenching. Alloy with lower volume fraction of recrystallization and smaller grain aspect ratio displays better corrosion resistance. The lower corrosion resistance caused by the slower cooling rate results from the higher coverage rate of grain boundary precipitates and larger width of precipitate free zone.
