Effect of heat treatment on microstructures and properties of a novel Al-Zn-Mg-Cu alloy for oil drilling

Publication date: Available online 20 April 2019Source: Progress in Natural Science: Materials InternationalAuthor(s): Yanjun Fu, Xiwu Li, Kai Wen, Shuhui Huang, Yang Dong, Mao Rao, Fubo Yang, Yugang Wang, Baiqing Xiong, Zhihui LiAbstractIn view of the special requirements for strength, heat resistance and corrosion resistance of Al-Zn-Mg-Cu alloy for oil drilling, the Al-6.2Zn-2.5Mg-1.6Cu alloy was prepared by increasing Cu content on basis of Russian Series 1953 alloy. The effect of heat treatment on the microstructures and properties of the alloy was characterized by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM), and investigated by tensile test at room temperature, thermal exposure test and corrosion test. The results show that the strength after T6 aging treatment exhibit a decrease trend as an increase of the solution temperature from 465 °C to 480 °C. After the solution treated by the rate of 470 °C/1 h, second phases dissolve into the matrix very well and the strength property reaches optimum. The alloy has better comprehensive properties treated by a solution treatment of 470 °C/1 h and then followed by an aging treatment of 120 °C/24 h + 170 °C/1 h + 120 °C/24 h. Under the aging state, the precipitated phases inside the grains are suitable in size, while on the grain boundary distribute discontinuously and the precipitate-free zone is obvious. Besides, the alloy still maintain high tensi...
Source: Progress in Natural Science: Materials International - Category: Materials Science Source Type: research