Mechanical properties of thermally-stable, nanocrystalline bainitic steels

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:700

Article

Hulme-Smith, C. N.¹  Bhadeshia, H. K. D. H.¹ 

[1] Univ Cambridge, Dept Mat Sci & Met, 27 Charles Babbage Rd, Cambridge CB3 0FS, England

关键词: Mechanical characterization;    Nanostructured materials;    Bainite;   

DOI  :  10.1016/j.msea.2017.04.110

来源: Elsevier

【 摘 要 】

Two novel, thermally stable bulk nanocrystalline bainitic steels were subjected to a range of mechanical tests. One alloy, containing 0.72 wt% carbon exhibited an ambient-temperature 0.2% proof strength of 1500 MPa and a fracture toughness of 64.6 MPa M1/2 after the bainite transformation. The other, containing 0.45 wt% carbon and 13.2 wt% nickel, had a 0.2% proof stress of 1000 MPa and a fracture toughness of 103.8 MPa m1/2 Both steels showed excellent creep resistance, with a rupture life at 450 degrees C and 700 MPa of 114 h and 94.8 h, respectively. Both displayed fatigue lives consistent with other steels of similar structure in the literature. After thermal exposure at 480 degrees C for 8 d, both steels increased in strength to 1800 MPa, and 1600 MPa, respectively. The latter steel reduced in fracture toughness to 19.6 MPa m1/2 These alloys are suitable for a range of engineering applications and remain so after thermal exposure. Combined with impressive high-temperature performance, this makes the current alloys candidates for use in some elevated temperature applications.

【 授权许可】

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