Cryogenic temperature toughening and strengthening due to gradient phase structure

Journal Article · Wed Nov 29 00:00:00 EST 2017 · Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing

DOI:https://doi.org/10.1016/j.msea.2017.11.107· OSTI ID:1461318

Ma, Zhiwei ^[1]; Ren, Yang ^[2]; Li, Runguang ^[3]; Wang, Yan-Dong ^[3]; Zhou, Lingling ^[1]; Wu, Xiaolei ^[1]; Wei, Yujie ^[1]; Gao, Huajian ^[4]

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1. Chinese Academy of Sciences (CAS), Beijing (China). State Key Lab. of Nonlinear Mechanics. Inst. of Mechanics; Univ. of Chinese Academy of Sciences, Beijing (China). School of Engineering Sciences
2. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source
3. Univ. of Science and Technology Beijing (USTB) (China). State Key Lab. for Advanced Metals and Materials
4. Brown Univ., Providence, RI (United States). School of Engineering

Cold embrittlement is one of the primary concerns challenging the usage of steels in infrastructures like pipelines and ocean platforms. This challenge is also compounded by the limited selection of materials for application in a cold and corrosive environment. Inspired by recent progresses in developing gradient structured materials with extraordinary properties, in this paper we report a class of stainless steels with gradient phase structures achieving a superb combination of strength (1753 MPa) and tensile ductility (>25%) at the cryogenic temperature of 77 K. A set of cylindrical steel samples acquire a graded mixture of hard martensitic and soft austenitic phases through pre-torsion, which results in an optimal stress partition in the material - the hard martensitic structures showing a positive density gradient from core to edge carry higher stress near the edge, while the soft austenitic phase showing a negative density gradient from core to edge serves to retain substantial tensile ductility. Finally, the phase-transformation at low temperature in gradient structures and the resulted work-hardening could be adopted to enhance the ductility and strength of widely used engineering materials for their applications in harsh environment.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States); Chinese Academy of Sciences (CAS), Beijing (China); Univ. of Science and Technology Beijing (USTB) (China)
• Sponsoring Organization: National Natural Science Foundation of China (NSFC); USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1461318
• Alternate ID(s): OSTI ID: 1549143; OSTI ID: 22829334
• Journal Information: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing, Journal Name: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing Vol. 712; ISSN 0921-5093
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
cryogenic
gradient
strengthening
synchrotron high-energy X-ray diffraction
toughening