Title: Forming limit analysis of AISI 316LN-austenitic stainless steel

Authors: R. Ramadoss, A. Rajadurai

Addresses: Department of Production Technology, Madras Institute of Technology, Anna University, Chennai, 600 044, India. ' Department of Production Technology, Madras Institute of Technology, Anna University, Chennai, 600 044, India

Abstract: Forming limit diagram (FLD) is an essential tool to evaluate the formability of sheet metals in various strain conditions. In this work, FLDs of two austenitic stainless steels of grades AISI 316L and 316LN of thickness 1 mm and 1.25 mm have been studied and their suitability for forming applications have been examined. From the experimental FLDs it is observed that 1.25 mm thickness sheet posses more formability than 1 mm sheet for both 316L and 316LN stainless steels. The micro structural aspects, tensile properties and formability parameters are experimentally determined and studied. Effect of nitrogen present in the 316LN stainless steel increases the strength and decreases the formability. The limiting strains for these steels under different strain conditions are analysed. The fracture surfaces of the formed samples in three different strain conditions namely tension-tension, plane strain and tension-compression regions are studied using scanning electron microscope (SEM). The SEM images are correlated with the fracture behaviour and formability of the sheet metal.

Keywords: austenitic stainless steel; punch forming; forming limit diagrams; FLD; microstructure; limiting strain; fractography; tensile properties; formability; fracture behaviour.

DOI: 10.1504/IJMMP.2009.031398

International Journal of Microstructure and Materials Properties, 2009 Vol.4 No.4, pp.436 - 454

Published online: 02 Feb 2010 *

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