Inter-relationship between microstructure evolution and mechanical properties in inertia friction welded 8630 low-alloy steel

Abstract The evolution of microstructure and mechanical properties in AISI 8630 low-alloy steel subjected to inertia friction welding (IFW) have been investigated. effects three critical process parameters, viz. rotational speed, forge forces, during tubular specimens were explored. these weld joints, including tensile Charpy V-notch impact studied for determining the optimum parameters. joints exhibited higher yield strength, lower hardening capacity ultimate strength compared base metal (BM). maximum ductility combination was achieved welds produced under a nominal speed ~ 2900–3100 rpm, highest force 680–720 kN, lowest axial forging load 560–600 kN. measured hardness distribution depicted values zone (WZ) thermo-mechanically affected (TMAZ), heat-affected (HAZ) BM, irrespective applied substantial increase WZ is due formation microstructures that dominated by martensite. observed microstructural features, i.e. fractions martensite, bainite ferrite, show temperature TMAZ above A c 3 , whereas HAZ below Ac 1 IFW. fracture surface impact-tested presence dimples nucleating from voids, thus indicating ductile failure. EBSD maps revealed subgrains inside prior austenite grains, occurrence continuous dynamic recrystallisation weld. Analysis crystallographic texture indicated (i.e. FCC) both undergoes simple shear deformation