Microstructural Evolution of Laser-Welded Dissimilar Lap Joints of Martensitic Abrasion Resistant Steel and Cold-Worked Austenitic Stainless Steel

Autor: Markku Keskitalo, Antti Järvenpää, Matias Jaskari, Atef Hamada, Mikko Hietala
Rok vydání: 2020
Předmět:
Zdroj: Key Engineering Materials. 861:15-22
ISSN: 1662-9795
DOI: 10.4028/www.scientific.net/kem.861.15
Popis: This paper investigates the effect of the energy input on the microstructure evolution and mechanical properties of laser-welded dissimilar lap joints of cold work-hardened austenitic stainless steel (CW-ASS) and martensitic abrasion resistant steel (AR600). Microstructure characterization of the welds was conducted using optical microscopy and electron backscatter diffraction in a scanning electron microscope. Subsequently, the mechanical properties of the dissimilar lap joints were determined using microhardness measurements and tensile tests. The microstructure observations show that the phase structure in the fusion zone (FZ) is predominantly ferritic at both energy inputs. Besides, the solidification microstructure in the FZ resembles the cast structure composed of cellular and columnar dendrites with exhibiting elemental segregations. The hardness reaches its peak in the FZ. However, the FZ near AR600 steel exhibited higher hardness values than that near CW-ASS. The dissimilar lap joints welded at low energy input 160 J/mm achieved a higher shear strength than those welded at high energy input 320 J/mm due to the softening of the weld in the former lap joint.
Databáze: OpenAIRE