Q ¼ h VvoltageIcurrentðWÞ (1)
where, Q, h, Vvoltage, and Icurrent are net heat input, arc efficiency, arc
voltage and current, respectively [23]. The heat of the molten
droplets is modeled using a volumetric body heat source and is
calculated as:
q ¼ QVpass W=m3 (2)
where q and Vpass are heat flux and volume of the weld pass,
respectively [24,25].
Natural and forced convection boundary conditions are
assumed on the outer and inner surfaces of the model, respectively.
The natural convection coefficient is taken as 28 W/m.K while the
forced convection coefficient is calculated according to Ref. [6].
Analyses were performed using a thermo-mechanical coupled
temperature-displacement procedure in ABAQUS™ version 6.11e2
commercial finite element package. Temperature dependent
thermo-mechanical properties of X65 [6] are adopted in the present
work for temperatures ranging from room temperature up to
1500 C. The material models adopted for pipe, sleeve and weld