Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7971616 | Materials Science and Engineering: A | 2018 | 20 Pages |
Abstract
An ultrahigh-strength CoCrFeMnNi high-entropy alloy wire rod was produced using cryogenic temperature caliber rolling. Because of the highly increased twinning activity caused by lowering the temperature to 77â¯K, significant twinning-induced grain refinement occurred; thus, an ultrafine (<â¯100â¯nm) grain structure could be achieved in the processed material. The processed material showed a remarkably high tensile strength of ~â¯1.7â¯GPa, and also had excellent resistance to hydrogen embrittlement (HE), in contrast to the typical trade-off relationship between these two properties. The exceptionally high resistance to HE was attributed to the combined effects of (1) difficulties in accumulating hydrogen owing to the sluggish hydrogen diffusion caused by the face-centered cubic crystal structure and the severe lattice distortion, (2) the high hydrogen threshold required for HE at the dominant cracking sites of twin boundaries, and (3) absence of martensite transformation.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Young Jin Kwon, Jong Woo Won, Sung Hyuk Park, Jeong Hun Lee, Ka Ram Lim, Young Sang Na, Chong Soo Lee,