Critical assessment of the strain-rate dependent work hardening behaviour of AISI 304 stainless steel

Kishore, Kaushal and Kumar, R Gaurav and Chandan, A K (2021) Critical assessment of the strain-rate dependent work hardening behaviour of AISI 304 stainless steel. Materials Science and Engineering A, 803 . p. 140675.

Full text not available from this repository.


In the present work, the effect of strain rate on the micro-mechanism of plastic deformation and ensuing work hardening behaviour of AISI 304 stainless steel has been critically investigated. The defining role of the early stage of deformation (<10% strain) on subsequent work hardening behaviour which is often ignored has been discussed in detail. It was found that there is a cross-over in the work hardening plot of slow strain rate (SSR) and high strain rate (HSR) specimen at around 5% strain and therefore to understand the sequential hardening behaviour, interrupted tensile tested specimens at 3, 10, 30% strain and up to the point of fracture were examined with respect to substructure evolution using transmission electron microscope and electron back-scattered diffraction. While the propensity of gamma ->alpha' in 3% strained specimen at HSR was higher contributing to lower transition strain from stage 1 to 2 of work hardening compared to SSR, the extent of work hardening was higher in the latter case during the stage 2 due to a combined effect of extensive twinning and deformation induced martensite formation, which was limited in HSR due to occurrence of cross-slip. These differences in the work hardening mechanisms were manifested as an improvement in UTS/YS ratio from 2.66 to 2.99 in HSR and SSR specimens, respectively. Furthermore, changes in the mechanism of plastic deformation was also reflected as similar to 4 fold increase in dislocation density for SSR specimen compared to HSR specimen at any given strain level and nearly 27% increase in hardness at the point of fracture. A significant improvement in UTS/YS ratio and ductility for SSR specimen left its signature on the fracture surface in form of three-fold increase in the number density of finer dimples compared to HSR specimen.

Item Type:Article
Official URL/DOI:DOI: 10.1016/j.msea.2020.140675
Uncontrolled Keywords:Austenitic stainless steel; Deformation induced martensite; Work hardening; Dislocation density; Quantitative fractography
Divisions:Material Science and Technology
ID Code:8378
Deposited By:Dr. A K Sahu
Deposited On:02 Jul 2021 13:06
Last Modified:02 Jul 2021 13:06
Related URLs:

Repository Staff Only: item control page