An Evaluation of Creep Behaviour in Friction Stir Welded MA754 Alloy

作者：Wang Jiye^*; Yuan Wei; Mishra Rajiv S; Charit Indrajit

来源：Journal of Materials Engineering and Performance, 2014, 23(9): 3159-3164.

DOI：10.1007/s11665-014-1092-7

• creep
• friction stir welding
• oxide dispersion strengthened alloy
• threshold stress

Effect of friction stir welding (FSW) on microstructure and creep properties of oxide dispersion strengthened (ODS) alloy MA754 were investigated. Fine-grained microstructure developed in the weld zone. TEM results showed some degree of particle agglomeration as a result of intense material flow. Creep tests of the FSW material were carried out at 973 and 1073 K. Power law creep behaviour was observed with stress exponent values of 6.9 and 6.3 at 973 and 1073 K, respectively. The results were compared to those of the as-received material. Creep resistance of FSW material was lower than that of as-received material associated with significantly reduced threshold stress. Post-weld annealing was carried out at 1598 K for 1 h. The heat treatment resulted in a coarse-grained microstructure and enhanced the creep resistance of the welded material. The creep data were compared with those of ODS Ni-Cr alloys in literature. The analysis shows the threshold stress of ODS alloys to be grain size- and temperature-dependent.

• 出版日期2014-9