关键词: 铝合金, 轧制变形量, 剥落腐蚀, 淬火敏感性, 晶界析出相

Abstract: This paper deals with the effect of rolling deformation on the quench sensitivity to the exfoliation corro- sion (EXCO) of thick Al-5Zn-3Mg-1Cu-0. 12Zr alloy plates by means of end-quenching testing,corrosion immer- sion testing,optical microscopy and transmission electron microscopy.The results show that (1) the resistance to EXCO of the plate decreases with the decrease in cooling rate,and the decrement of EXCO resistance increases with the increase in hot rolling deformation,which means that there exists an increasing quench sensitivity to EX- CO; (2) when the rolling deformation ranges from 56% to 91%,the exfoliation corrosion levels of all the samples are P at a quench rate of 2160℃ /min,while the level varies from EA to ED at a quench rate of 100℃ /min; (3) when the rolling deformation is 56%,72%,81% and 91%,the exfoliation corrosion level is EA or deeper than EA at the quench rates of more than 100,159,209 and 320 ℃ /min; and (4) under a constant rolling deforma- tion,the precipitate free zone will be widened with the decrease of quench rate,which may result in the degrada- tion of the exfoliation corrosion resistance.

Key words: aluminum alloy, rolling deformation, exfoliation corrosion, quench sensitivity, grain boundary precipitate