时效工艺对2519铝合金热轧板材抗应力腐蚀敏感性的影响

Influence of Different Ageing Process on Stress Corrosion Cracking Sensitivity of 2519 Aluminum Alloy Hot Rolled Plate

以腐蚀的强度指标(Kσ)和腐蚀的伸长率指标(Kδ)评定合金的抗应力腐蚀敏感性,研究了2519铝合金热轧板材在T6、T7和T8状态下的抗应力腐蚀敏感性。试验结果表明,2519铝合金热轧板材的抗应力腐蚀敏感性按T8>T7>T6排序,而它们的力学性能按T6>T8>T7的顺序排列。另外,测试了室温下T6、T7和T8状态2519铝合金试样的恒电位极化曲线,发现可以以合金的极化电阻定性地描述合金的抗应力腐蚀敏感性,且当合金的极化电阻越大时,合金的抗应力腐蚀敏感性越好。

The stress corrosion cracking (SCC) sensitivity was evaluated with parameters such as K_ σ(strength index) and K_ δ(elongation index). The SCC sensitivities of T6,T7,T8 treated 2 519 aluminum alloy hot rolled plate were investigated. The experiments indicate that SCC sensitivity ranks in the order of T8>T7>T6 while mechanical properties rank in the order of T6>T7>T8. The potentiostatic polarization curves tests were carried out at room temperature for T6,T7,T8 treated 2519 aluminum alloy. The electrochemical corrosion behavior of stressed samples shows that the SCC sensitivity can be assessed by polarization resistance (R_ p), so the higher the R_ pis,the better the SCC resistance is.