Work

Creep rupture of smoothed and notched DD6 single crystal superalloy specimens subjected to high-temperature hot corrosion

Year: 2024

Type: article

Abstract: This work studies the creep rupture behaviors of both smoothed and V-notched DD6 Ni-based single crystal superalloy specimens under varying conditions, including air, pre-corrosion and coupled corrosion, within a stress range of 300 to 700MPa at 950 oC. The corrosive medium used consisted of a mixed salt containing 95wt.% Na2SO4 and 5wt.% NaCl. Experimental results revealed that notched specimens exhibited a creep rupture life extended by 6–16 times compared to smoothed specimens, with the extension becoming more pronounced as the stress concentration increased. High temperature hot corrosion (HTHC) shortened the creep rupture time by up to 75%. A significant HTHC-creep interactive effect was found through comparative pre-corrosion and coupled corrosion experiments. The HTHC affected the failure modes of the specimens, with factors such as the amount of salt infiltration into the superalloy, the corrosion duration and specimen configurations playing critical roles. Microstructural analysis revealed that, compared with [[EQUATION]] precipitates, [[EQUATION]] matrix phase was more prone to creep damage and was more susceptible to corrosion.

Source: Materials & Design

DOI: 10.1016/j.matdes.2024.113526

Authors: Baishun Yang, Biao Li, Yaning Zhang

Institution: Northwestern Polytechnical University

Language: English

Topic: High Temperature Alloys and Creep

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,200

Funders: National Natural Science Foundation of China, National Major Science and Technology Projects of China