ABSTRACT:Objective To study the anti-environment corrosion properties of 2D12 alloy. Methods According to the standard test methods, the corrosion tests including intergranular corrosion test, exfoliation test and stress corrosion cracking test were carried out for 2D12 Al-Mg-Cu aluminum alloys with different specifications, and the test data was analyzed and evaluated. Results The intergranular corrosion depth, exfoliation degree, stress corrosion cracking time and threshold stress intensity factor for susceptibility to stress corrosion cracking (KICC) were obtained. There was intergranular corrosion tendency for 2D12 aluminum in natural aging condition, and the maximum intergranular corrosion depth was 0.18 mm. The anti-exfoliation corrosion property of 2D12 aluminum alloys with differentspecifications varied from P to Ec degree. The tensile stress corrosion cracking time decreased with the increase of the test stress, and the critical stress corrosion threshold of two sheets (δ=1.5 mm andδ=2.0 mm) and EL2805 section bar were 160, 140 and 230 MPa, respectively. The KICC values of S-L and S-T orientation were 22.6 MPa·m1/2 and 27.1 MPa·m1/2, respectively. Conclusion The anti-stress corrosion test of 2D12 aluminum alloy showed that the anti-SCC property of S-L orientation was lower than that of S-T orientation, which was in accordance with the C-ring result, and the fractographies of 2D12 aluminum revealed typical intergranular fracture stress corrosion cracking characteristics.%目的：研究2D12铝合金耐环境腐蚀性能。方法对不同规格的Al-Cu-Mg系2D12铝合金的耐环境腐蚀性能包括晶间腐蚀、剥蚀性能以及抗应力腐蚀性能，按照标准试验方法进行测试、分析、评定试验数据。结果得到了不同规格2D12铝合金晶间腐蚀深度、剥蚀等级、应力腐蚀断裂时间及KISCC等。自然时效状态2D12铝合金具有晶间腐蚀倾向，最大晶间腐蚀深度为0.18 mm。不同规格2D12铝合金抗剥落腐蚀性倾向不同，从P级到EC级。2D12铝合金材料的拉伸应力腐蚀断裂寿命随试验应力的增加而降低，两种薄板（δ=1.5 mm和δ=2.0 mm）和型材（EL2805）临界应力腐蚀门槛值分别为160，140，230 MPa。2D12铝合金在S-L和S-T方向的应力腐蚀开裂门槛应力强度因子分别为22.6 MPa·m1/2和27.1 MPa·m1/2。结论2D12铝合金抗应力腐蚀测试结果表明， S-L方向比S-T方向的抗应力腐蚀的性能低，其应力腐蚀开裂门槛应力强度因子与C环应力腐蚀结果一致，断口呈现典型的沿晶断裂应力腐蚀脆性断裂特征。
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