A pathway to produce strong and tough martensitic stainless steels resistance spot welds. (3rd April 2019)

• Record Type: Journal Article
• Authors: Aghajani, H.; Pouranvari, M.
• Is Part Of: Science and technology of welding & joining. Volume 24:Number 3(2019)
• Page Start: 185
• Page End: 192
• Publication Date: 2019-04-03
• Subjects: Martensitic stainless steel -- resistance spot welding -- nickel interlayer -- energy absorption -- microstructure; Welding -- Periodicals; Joints (Engineering) -- Periodicals; Surfaces (Technology) -- Periodicals; 671.52
• DOI: 10.1080/13621718.2018.1483065
• Languages: English
• ISSNs: 1743-2936

Abstract

ABSTRACT: Martensitic stainless steel (MSS) resistance spot welds are prone to quasi-cleavage interfacial failure with very low energy absorption capability due to formation of hard and brittle carbon and chromium rich martensite in the fusion zone (FZ). In this work, a new pathway is proposed to enhance strength/toughness of the MSS resistance spot welds based on modification of the FZ composition/microstructure via introducing a nickel interlayer. This altered the FZ microstructure from dual phase microstructure of martensite and δ-ferrite to austenitic microstructure with finely dispersed ultra-fine chromium rich carbides. Formation of a tough predominately austenitic microstructure in the FZ enabled achieving a pullout failure with an unprecedented level of energy absorption.