Dislocation evolution in 316 L stainless steel during multiaxial ratchetting deformation

Journal Article · Thu Mar 15 04:00:00 EDT 2012 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2012.01.004· OSTI ID:22066426

Yawei, Dong ^[1]; Yujie, Liu; Hong, Wang; Xiaojuan, Cheng ^[2]

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1. State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China)
2. School of Mechanics and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

Dislocation patterns and their evolutions in 316 L stainless steel during the multiaxial ratchetting deformation were observed by transmission electron microscopy (TEM). The microscopic observations indicate that the dislocation evolution presented during the multiaxial ratchetting with four kinds of multiaxial loading paths is similar to that in the uniaxial case [G. Z. Kang et al., Mater Sci Eng A 527 (2010) 5952]. That is, dislocation networks and dislocation tangles are formed quickly by the multiple-slip and cross-slip of dislocation activated by applied multiaxial stress; and then polarized patterns such as dislocation walls and elongated incipient dislocation cells are formed at the last stage of multiaxial ratchetting. The dislocation patterns evolve more quickly from the modes at low dislocation density to the ones at high density during the multiaxial ratchetting than that in the uniaxial case, and some traces of multiple-slip are observed in the multiaxial ones. The dislocation evolution during the multiaxial ratchetting deformation is summarized by comparing the observed dislocation patterns with those presented in the multiaxial strain-controlled and symmetrical stress-controlled cyclic tests. The multiaxial ratchetting of 316 L stainless steel can be microscopically and qualitatively explained by the observed evolution of dislocation patterns. - Highlights: Black-Right-Pointing-Pointer Dislocation patterns change from lines and nets to tangles, walls and cells. Black-Right-Pointing-Pointer Dislocation patterns evolve quicker in the multiaxial case. Black-Right-Pointing-Pointer Aligned dislocation arrays and some traces of multiple slips are observed. Black-Right-Pointing-Pointer Heterogeneous dislocation patterns result in the multiaxial ratchetting.

• OSTI ID: 22066426
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: Complete Vol. 65; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DEFORMATION
DISLOCATIONS
LOADING
SLIP
STAINLESS STEEL-316L
STRAINS
STRESSES
TRANSMISSION ELECTRON MICROSCOPY