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研究了时效制度对Ａｌ－Ｚｎ－Ｍｇ－Ｃｕ合金（ＬＣ４）双悬臂梁（ＤＣＢ）试样的残余应力分布及其对应力强度因子、腐蚀开裂行为的影响。结果表明，轴向残余拉应力可以引起试样弯曲成弓形，相当于ＤＣＢ试样附加一应力强度因子Ｋ１Ｒ，Ｋ１Ｒ随时效温度提高而减小。在自然时效状态Ｋ_（１Ｒ）约１０ＭＰａ·ｍ￣（１／２），１２０℃时效时态Ｋ_（１Ｒ）约７．５ＭＰａ·ｍ￣（１／２）时，无外加载荷均可产生严重的腐蚀开裂现象，且具有沿晶断裂特征并呈特殊的长舌形区。１６０℃时效状态未出现腐蚀开裂现象，对其原因进行了讨论。
The effect of aging system on the residual stress distribution and its effect on the stress intensity factor and corrosion cracking of Al-Zn-Mg-Cu alloy (LC4) double-cantilever (DCB) The results show that the axial residual tensile stress can cause the specimen to bend into a bow shape, which is equivalent to adding a stress intensity factor K1R to the DCB specimen. The K1R decreases with the aging temperature. Under the natural aging condition of K_ (1R) of about 10MPa · m ~ (1/2) and 120 ℃ aging time K_ (1R) of about 7.5MPa · m ~ (1/2), no external load can produce serious Corrosion cracking phenomenon, and has the characteristics of intergranular fracture and was a special long tongue-shaped area. The phenomenon of corrosion and cracking did not appear at the aging state of 160 ℃, and the reason was discussed.