Inconel 718 alloy is a high-Nb age-strengthened Ni-Cr-Fe-based deformed high-temperature alloy with excellent high-temperature and mechanical properties and is widely used in aerospace and other fields. However, when the service temperature of Inconel 718 alloy exceeds 650°C, the γ” phase will quickly aggregate and grow and transform into δ phase, and the strength of the alloy will decrease rapidly. In order to increase the service temperature of Inconel 718 alloy, a lot of research has been carried out at home and abroad. Among them , the Inconel 718 Plus alloy developed in the United States has increased the service temperature to 704°C, and its composition has been greatly adjusted to the Inconel 718 alloy. The change in Co and Al content has a particularly important impact on the alloy properties.
Co is an important strengthening element that can increase the creep resistance and high-temperature strength of the alloy. However, the standard composition ofInconel 718 alloy stipulates that the Co content is <1.0 wt%, so the role of Co in Inconel 718 series alloys is not yet fully understood. Studies have shown that an appropriate amount of Co content can improve the high-temperature strength and creep resistance of the alloy, but when the Co content is too high, the cold work hardening ability of the alloy will be reduced.
Al is a commonly used γ” phase inhibitory element, which can inhibit the precipitation of γ” phase and improve the high-temperature strength and creep resistance of the alloy. However, in addition to inhibiting the precipitation of γ” phase, the increase in Al content will also promote the precipitation of harmful phases such as Laves and σ. Therefore, the control of Al content is very critical, and a balance point needs to be found to effectively suppress the γ” phase. , and the precipitation of harmful phases is controlled.
In order to further study the role of Co and Al in Inconel 718-based alloy, this paper conducted a series of experimental studies. The results show that appropriate amounts of Co and Al can significantly improve the high-temperature strength and creep resistance of the alloy. When the Co content is 1.5 wt% and the Al content is 1.2 wt%, the high-temperature strength and creep resistance of the alloy are maximized. At this time, the γ’ phase mainly precipitates in the grains of the alloy, and the main strengthening phase at the grain boundary is the eta phase, while the precipitation of the γ” phase and the δ phase has been effectively suppressed. In addition, as the Co and Al content increase, the plasticity of the alloy decreased, while the hardness and strength were increased.
In summary, Co and Al have a significant impact on the structure and mechanical properties of Inconel 718-based alloy. Appropriate amounts of Co and Al can improve the high-temperature strength and creep resistance of the alloy, but attention needs to be paid to the reduction in plasticity of the alloy, and the precipitation of harmful phases also needs to be controlled.
Tianjin Anton Metal Manufacture Co., Ltd. is a company specializing in the production of various nickel-based alloys, Hastelloy alloys and high-temperature alloy materials. The company was established in 1989 with a registered capital of 10.0 million, specializing in the production and sales of alloy materials. Anton Metal’s products are widely used in aerospace, chemical industry, electric power, automobile, nuclear energy and other fields, and can also provide customized alloy material solutions according to customer needs. If you need to know the price consultation of alloy materials or provide customized alloy material solutions, please feel free to contact the sales staff.
==========================================
www.antonmetal.com
ANTON METAL｜ Your specialty alloys manufacturer
Email: dominic@antonmetal.com
Phone: +8613132148618(wechat/whatsapp)
Post time: Nov-18-2023
