Microstructure and fatigue behaviour of spin-arc welded AISI C1018 low carbon steel

Abstract

This work investigates the fatigue performance of 10 mm AISI C1018 low carbon steel plates welded with ER70S-6 using a gas metal arc welding-based spin-arc welding process. Welded joint microstructure is characterized by bainite, acicular ferrite, and allotriomorphic ferrite along with pearlite in the ferritic matrix. The tensile strength of the weld metal was comparable with base metal and meets the mechanical property requirements in accordance with the ASTM A311/A311M-04 (2020) standard. The fatigue strengths of base metal and weld metal are 121 and 126 MPa, respectively, after sustaining 106 cycles. During cyclic loading, fracture surfaces were distinctly noticed as the crack initiation, crack propagation, and final rupture regions. The decrease in alternating stress increased the fatigue cycles to final rupture, and the nature of fatigue fracture was ductile with dimples and voids.