Tailoring mechanical behavior of a fine-grained metastable austenitic stainless steel by pre-straining
| Autor: | Longfei Li, Dehui Li, Juan Ye, Heng Jiang, Chengsi Zheng, Xiyun Hao |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Annealing (metallurgy) Mechanical Engineering Alloy Kinetics food and beverages 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Mechanics of Materials 0103 physical sciences engineering Hardening (metallurgy) General Materials Science Austenitic stainless steel Composite material 0210 nano-technology Shear band Necking |
| Zdroj: | Materials Science and Engineering: A. 746:332-340 |
| ISSN: | 0921-5093 |
| DOI: | 10.1016/j.msea.2019.01.038 |
| Popis: | A fine-grained AISI 304 austenitic stainless steel (ASS) was fabricated by cryogenic-rolling and cycle annealing. The fine-grained ASS was pre-strained to various strains of 0–0.16, and the corresponding microstructures, kinetics of strain-induced α′-martensite (SIMα′) and work-hardening behavior were investigated based on quantitative characterization, interrupted-tensile tests and physical metallurgy. We find that the yield strength of the ASS can be enhanced by combining grain-refining with pre-straining due to the strengthening effect of grain-refinement, dislocations, shear bands and SIMα′. The formation rate of shear band increases with increasing pre-strain (ep) and the probability for an intersection of shear band to form a SIMα′ embryo is insensitive to the pre-strain, and as a result, the kinetics of SIMα′ is accelerated by pre-straining. The fine-grained ASS with ep ≈ 0–0.16 display a three-stage work-hardening behavior, and the corresponding Stage I, II and III are completed in advance mainly due to their faster kinetics of SIMα′ and severer dynamic recovery caused by pre-straining. The work-hardening rate (Θ) of pre-strained fine-grained ASS decreases faster than that of non-pre-strained counterpart at Stage I, accompanying with dislocations-dominated hardening. The Θ ascend with increasing strain to a peak value at Stage II and then decline continuously to necking at Stage III, following as SIMα′-governed hardening, which can be tailored by grain-refining and pre-straining. Our studies provide the direct experimental evidence for the pre-straining to trim the kinetics of SIMα′ in a fine-grained ASS. These observations help to deepen understanding of the effect of pre-strain on the mechanical behavior of other fine-grained strengthening ASS and transformation-induced-plasticity (TRIP) assisted alloy. |
| Databáze: | OpenAIRE |
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