Gradient plastic strain accommodation and nanotwinning in multi-pass laser shock peened 321 steel

Karthik, D and Yazar, K U and Bisht, Anuj and Swaroop, S and Srivastava, Chandan and Suwas, Satyam (2019) Gradient plastic strain accommodation and nanotwinning in multi-pass laser shock peened 321 steel. In: APPLIED SURFACE SCIENCE, 487 . pp. 426-432.

PDF app_sur_sci_487_426_2019.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

In this study gradient plastic strain accommodation and nanotwinning are investigated in detail using electron back scattered diffraction (EBSD) and transmission electron microscopy (TEM) techniques in AISI 321 steel after laser shock peening without applying surface protective coatings, employing multiple zigzag peening passes (3 times and 5 times). On the peened specimens, three regions, as identified by residual stress and hardness results, namely, thermally affected region (from top peened surface to 20 mu m), severe plastically deformed region (beneath 20 mu m up to 100 mu m depth) and minor plastically deformed region (beneath 100 mu m up to 180 mu m depth) were observed. Significant grain orientation spread and increased low-angle grain boundaries were noticed in severe plastically deformed region. The accommodation of plastic strain after laser peening gradually decreased from 20 mu m from peened surface. Nanotwins of varying width, in particular, multiple twinning within twin-matrix after 5 times laser peening passes were observed after peening. Interestingly nanotwins were bundled within an austenitic grain after peening with 5 passes.

Item Type:	Journal Article
Publication:	APPLIED SURFACE SCIENCE
Publisher:	ELSEVIER SCIENCE BV
Additional Information:	copyright for this article belongs to ELSEVIER SCIENCE BV
Keywords:	Multi-pass LPwC; Austenitic steel; EBSD; TEM; Plastic strain; Nanotwinning
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	31 Jul 2019 09:52
Last Modified:	31 Jul 2019 09:52
URI:	http://eprints.iisc.ac.in/id/eprint/63159

Actions (login required)

View Item