Hardenability of 7A04 Al alloy super thick plate
Chen Yuanqing, He Kezhun, Yao Xiang, Wei Xiuxun, Zhang Hang, Chen Shaowen
2020, 45(5):
166-171.
doi:10.13251/j.issn.0254-6051.2020.05.032
Abstract
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The microstructure, properties and hardenability of the 7A04 Al alloy super thick plate were studied by means of universal mechanical testing machine, optical microscope and scanning electron microscope. The results show that when the 225 mm thick 7A04 Al alloy hot rolled plate is solid solution treated at 475 ℃ for 340 min with water quenching, then artificially aged at 120 ℃ for 24 h, the surface mechanical properties of the plate are the optimum, with the tensile strength, yield strength, and elongation being 584 MPa, 500 MPa, and 11%, respectively. However, the T/4 thickness layer gets the poorest property combination, with the tensile strength, yield strength, and elongation being 396 MPa, 257 MPa, and 11%, that is, the tensile strength and yield strength differ from that of the surface by 32% and 49%, respectively. The one-side quenching depth is 32 mm. By adjusting the chemical composition, increasing rolling reduction and increasing quenching cooling rate, the differences of mechanical properties between the plate surface and center can be improved, so is the hardenability.
