δ-phase precipitation regularity of cold-rolled fine-grained GH4169 alloy plate and its effect on mechanical properties
(1. Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education, Yanshan University, Qinhuangdao 066004, China;
2. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China)
2. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China)
Abstract: Cold rolling and heat-treatment were used for the grain refinement of GH4169 superalloy plate. The effects of cold rolling reduction ratio and heat-treatment time on the precipitated δ phase, and the effects of δ-phase content and morphology on the mechanical properties of the GH4169 alloy plates, are studied. The results demonstrate that cold- rolling can promote the precipitation of the δ phase and its transformation from the δ-Ni3Nb phase to the δ-NbNi4 phase. The comprehensive properties of the alloy are better when the heat treatment time is 1 h, with 132 MPa increase in the tensile strength and only 2.9% decrease in the elongation relative to those of the original material. The mechanical properties of the alloy are shown to change greatly with the change in the δ-phase morphology.
Key words: fine-grained GH4169 alloy; cold rolling; δ phase; mechanical properties