The tensile behavior of GH3535 superalloy at elevated temperature

The tensile behavior of GH3535 alloy has been investigated at strain rates of 8.33 x 10(-5)/s(-1) -8.33 x 10(-3)/s(-1), in the temperature range of 25-800 degrees 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 degrees 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 degrees 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 degrees 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 degrees C, whereas type C serration was noticed when the temperature rose above 650 degrees 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. (C) 2016 Elsevier B.V. All rights reserved.