热处理制度对705铝合金力学性能和应力腐蚀开裂的影响

EFFECT OF HEAT TREATMENT ON MECHANICAL PROPERTIES AND STRESS CORRODED CRACKING OF 705 Al ALLOYS

选用四种不同的热处理制度对７０５铝合金进行处理。结果表明，７０５铝合金板材原供货态短横向上的抗应力腐蚀能力很低，裂纹扩展平台速率较高，应力腐蚀开裂界限应力强度因子（ＫⅠｓｃｃ）值较低。而淬火后室温放置３天＋１００℃保温８ｈ＋１２０℃保温２４ｈ处理状态下的力学性能同供货态相当，而应力腐蚀开裂界限应力强度因子高于性能指标，达９．７４ＭＰａ·ｍ１／２。

Four different heat treatments have been selected for 705 Al alloys. The result shows that the stress corrosion resistance of the primary supplied state,with the short transverse (TL) orientation, is very low .The crack expansion velosity is high and the stress corroded intensity factor (K Iscc ) is low .After quenching ,they were kept for 3 days at the room temperature.Their mechanical properties at the state of 100℃×8h+120℃×24h are equivalent to the supplied state,while their K Iscc is increased to 9.74MPa·m 1/2 more than that of the primary ones.