The tensile behavior of GH3535 superalloy at elevated temperature

• Published in: Materials chemistry and physics Vol. 182; pp. 22 - 31
• Main Authors: Han, F.F., Zhou, B.M., Huang, H.F., Leng, B., Lu, Y.L., Dong, J.S., Li, Z.J., Zhou, X.T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2016
• Subjects: Alloying additive; Alloys; Carbides; Grain boundaries; High temperature; Mechanical properties; Microstructure; Migration; Strain rate; Stress strain curves; Stress-strain relationships; Yield strength; Mechanical properties; Microstructure; Carbides; Alloys
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2016.07.001

The tensile behavior of GH3535 alloy has been investigated at strain rates of 8.33 × 10−5/s−1–8.33 × 10−3/s−1, in the temperature range of 25–800 °C. The results showed that the ultimate tensile strength was decreased with increasing temperature and increased with rising strain rate, whereas the yield strength kept almost a constant value at the temperature range from 550 to 800 °C in all strain rates test. The formation of M12C carbides at the grain boundary during the tension process played an important role in increasing the yield strength of the alloy at elevated temperatures. But inhomogeneous deformation at 650 °C resulted in the minimum ductility of the alloy. Additionally, various types of serrations were noticed on the stress-strain curves for the alloy tested in the temperature range of 500–800 °C. Normal Portevin-Le Chatelier (PLC) effect and positive strain rate sensitivity were observed in this alloy. Type A and A + B serrations were presented to stress-strain curves at temperatures below 650 °C, whereas type C serration was noticed when the temperature rose above 650 °C. The analysis suggested that the interactions between substitutional solutes migration and mobile dislocations were the main reason for the serrated flow behavior in this alloy.
•The tensile behavior of GH3535 alloy at elevated temperature was studied.•The yield strength anomaly was observed in the temperature range from 550 to 800 °C.•The formation of M12C improves the grain boundary strength to a certain extent.•Inhomogeneous deformation at 650 °C results in the ductility loss of the alloy.•The interaction between solute atoms and dislocations results in the PLC effect.