Mechanical behaviors of alloy 617 with varied strain rates at high temperatures
2014 (English)In: THERMEC 2013, Trans Tech Publications Ltd , 2014, Vol. 783-786, 1182-1187 p.Conference paper (Refereed)
Nickel base alloys due to their high performances have been widely used in biomass and coal fired power plants. They can undertake plastic deformation with different strain rates such as those typically seen during creep and fatigue at elevated temperatures. In this study, the mechanical behaviors of Alloy 617 with strain rates from 10-2/s down to 10-6/s at temperatures of 650C and 700C have been studied using tensile tests. Furthermore, the microstructures have been investigated using electron backscatter detection and electron channeling contrast imaging. At relatively high strain rate, the alloy shows higher fracture strains at these temperatures. The microstructure investigation shows that it is caused by twinning induced plasticity due to DSA. The fracture strain reaches the highest value at a strain rate of 10-4/s and then it decreases dramatically. At strain rate of 10-6/s, the fracture strain at high temperature is now smaller than that at room temperature, and the strength also decreases with further decreasing strain rate. Dynamic recrystallization can also be observed usually combined with crack initiation and propagation. This is a new type of observation and the mechanisms involved are discussed. © (2014) Trans Tech Publications, Switzerland.
Place, publisher, year, edition, pages
Trans Tech Publications Ltd , 2014. Vol. 783-786, 1182-1187 p.
, Materials Science Forum, ISSN 0255-5476
Dynamic strain ageing; Elevated temperature; Nickel base super alloy; Twinning
IdentifiersURN: urn:nbn:se:liu:diva-116728DOI: 10.4028/www.scientific.net/MSF.783-786.1182ScopusID: 2-s2.0-84904564494ISBN: 9783038350736OAI: oai:DiVA.org:liu-116728DiVA: diva2:801365
8th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2013