(1. 北京有色金屬研究總院 有色金屬材料制備加工國家重點(diǎn)實驗室，北京 100088； 2. 東北輕合金有限責(zé)任公司，哈爾濱 150060)
摘 要: 7xxx系鋁合金在淬火后會產(chǎn)生較大的殘余應(yīng)力，且淬火介質(zhì)對淬火殘余應(yīng)力的水平與分布影響顯著。通過裂紋柔度法研究不同淬火介質(zhì)種類、溫度和濃度對淬火殘余應(yīng)力的影響規(guī)律。結(jié)果表明：淬火殘余應(yīng)力符合典型的“外壓內(nèi)拉”分布，淬火殘余應(yīng)力水平隨水溫升高先緩慢降低后急速降低，隨PAG濃度升高先迅速降低后緩慢降低。各淬火介質(zhì)下應(yīng)力水平由高到低的順序依次為5%NaCl+5%KNO3溶液(質(zhì)量分?jǐn)?shù))、20 ℃水、5%PAG溶液(體積分?jǐn)?shù))。在80 ℃水和15%PAG溶液(體積分?jǐn)?shù))淬火后，殘余應(yīng)力水平降低比例最大均達(dá)到60%以上，抑制殘余應(yīng)力效果明顯。
關(guān)鍵字: 7055鋁合金；淬火殘余應(yīng)力；裂紋柔度法；淬火介質(zhì)
（1. State Key Laboratory of Nonferrous Metals and Processes, General Research Institute for Nonferrous Metals, Beijing 100088, China; 2. Northeast Light Alloy Co., Ltd., Harbin 150060, China）
Abstract:Large residual stress produces after quenching in 7xxx series aluminum alloy and quenching medium influences the quenching residual stress obviously. In this work, the effects of quenching medium type, temperature, concentration on quenching residual stress were studied by using the crack compliance method. The results show that the quenching residual stress with typical distribution decreases slowly at first and then decreases rapidly with water temperature rising, while decreases rapidly at first and then decreases slowly with the increasing of PAG concentration. The stress level of each quenching medium from high to low is as follows: 5%NaCl+5%KNO3 solution (mass fraction), 20 ℃ water, 5%PAG solution (volume fraction). After quenching at 80 ℃ water or 15%PAG solution (volume fraction), the reduction ratio of residual stress level is above 60%, thus the reduction of quenching residual stress is obvious.
Key words: 7055 aluminum alloy; quenching residual stress; crack compliance method; quenching medium
