Effects of process parameters and thermo-mechanical simulation of GMAW process for welding of 3Cr12 steel

Abstract

Stainless steel has wide applications and the demand for stainless steel is increasing worldwide. In this paper, gas metal arc welding process is used for the welding of 3Cr12 steel considering welding voltage, welding speed, wire feed speed and gas flow rate as input process parameters. The experiments are conducted using central composite design matrix and the bead geometry parameters like bead height, bead width, bead penetration and mechanical properties like tensile strength and hardness are measured. The mathematical models for bead geometry parameters and mechanical properties are developed and the effects of process parameters on bead geometry parameters, mechanical properties and microstructure are found out. The tensile tests shows that fracture occurred at weld zone due to high welding voltage which gives high heat input and forms larger cast dendritic structure in weld zone region. The higher hardness is observed at heat-affected zone than at base metal and the weld zone. The microstructure shows ferrite and pearlite structures with variation in amount with coarse and fine grain size. The thermo-mechanical simulation is also carried out and shows the normal, transverse and longitudinal stresses are compressive and von-Mises stresses are tensile in nature and are maximum at weld zone.