About this Abstract |
Meeting |
Superalloys 2024
|
Symposium
|
Superalloys 2024
|
Presentation Title |
Influence of Re on High-temperature Microstructural Stability and Mechanical Properties of High-Cr CoNi-based Superalloys |
Author(s) |
Xiaorui Zhang, Longfei Li, Song Lu, Muchun Hou, Min Zou, Qiang Feng, Siliang He |
On-Site Speaker (Planned) |
Siliang He |
Abstract Scope |
A multicomponent high-Cr CoNi-based superalloy was developed for potential use in industrial gas turbine materials. In response to the enhanced overall performance of alloys, the microstructural stability and strength of alloys with different Re additions at 950 °C were investigated. During long-term thermal exposure, the ã′ precipitates remained nearly cuboidal and the addition of Re led to a mild decrease in the ã′ volume fraction. The Re addition can effectively reduce the coarsening rate of ã′ precipitates due to both the significant reduction in the effective diffusion coefficient in the ã matrix and the decrease in interfacial energy between the ã and ã′ phases. Despite a reduction in ã′ volume fraction, the addition of Re improved the creep properties of the investigated alloys at 950 °C/200 MPa - 300 MPa. Firstly, the introduction of Re causes the inversion of W partitioning from ã matrix to ã′ precipitates to improve the ã′ strength. And it also elevates the content of Re within the ã phase, thereby enhancing the solid solution strengthening effect. Moreover, this improvement is also attributed to a decrease in the effective diffusion coefficient of the alloy. All these factors contribute to improving the creep properties and yield strength of high-Cr CoNi-based superalloys. |
Proceedings Inclusion? |
Definite: At-meeting proceedings |