自然时效对A201-T7铝合金应力腐蚀开裂行为的影响

Effect of Natural Aging on the Stress Corrosion Cracking Behavior of A201-T7 Aluminum Alloy.

作者信息

Chen Mien-Chung, Wen Ming-Che, Chiu Yang-Chun, Pan Tse-An, Tzeng Yu-Chih, Lee Sheng-Long

机构信息

Institute of Material Science and Engineering, National Central University, Taoyuan 320, Taiwan.

Department of Mechanical Engineering, National Central University, Taoyuan 320, Taiwan.

出版信息

Materials (Basel). 2020 Dec 10;13(24):5631. doi: 10.3390/ma13245631.

DOI:10.3390/ma13245631

PMID:33321779

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7764127/

Abstract

The effect of natural aging on the stress corrosion cracking (SCC) of A201-T7 alloy was investigated by the slow strain rate testing (SSRT), transmission electron microscopy (TEM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), conductivity, and polarization testing. The results indicated that natural aging could significantly improve the resistance of the alloys to SCC. The ductility loss rate of the unaged alloy was 28%, while the rates for the 24 h and 96 h aged alloys were both 5%. The conductivity of the as-quenched alloy was 30.54 (%IACS), and the conductivity of the 24 h and 96 h aged alloys were decreased to 28.85 and 28.65. After T7 tempering, the conductivity of the unaged, 24 h, and 96 h aged alloys were increased to 32.54 (%IACS), 32.52 and 32.45. Besides, the enthalpy change of the 24 h and 96 h aged alloys increased by 36% and 37% compared to the unaged alloy. The clustering of the solute atoms would evidently be enhanced with the increasing time of natural aging. Natural aging after quenching is essential to improve the alloy's resistance to SCC. It might be due to the prevention of the formation of the precipitation free zone (PFZ) after T7 tempering.

摘要

通过慢应变速率试验（SSRT）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、差示扫描量热法（DSC）、电导率测试和极化测试，研究了自然时效对A201-T7合金应力腐蚀开裂（SCC）的影响。结果表明，自然时效可显著提高合金的抗应力腐蚀开裂性能。未时效合金的延性损失率为28%，而时效24小时和96小时的合金的延性损失率均为5%。淬火态合金的电导率为30.54（%IACS），时效24小时和96小时的合金的电导率分别降至28.85和28.65。经过T7回火后，未时效、时效24小时和96小时的合金的电导率分别提高到32.54（%IACS）、32.52和32.45。此外，时效24小时和96小时的合金的焓变比未时效合金分别增加了36%和37%。随着自然时效时间的增加，溶质原子的聚集将明显增强。淬火后的自然时效对于提高合金的抗应力腐蚀开裂性能至关重要。这可能是由于防止了T7回火后无沉淀区（PFZ）的形成。