Weldability of Ferritic Ductile Cast Iron Using Full Factorial Design of Experiment

The weldability of a ferritic ductile cast iron was investigated as a function of different consumables and welding conditions. A 23 full factorial experimental design was used to analyze the effect of factors and their interactions on ultimate tensile strength of weldments. The shielded metal are welding (SMAW) process was used with two types of consumables (E7018 and ENi-CI) under eight different conditions using as-cast samples. The microstructural evolution and fracture mechanisms were investigated by optical microscopy and scanning electron microscopy (SEM), respectively. The hardness, tensile and impact tests were also performed to determine the weld quality. Based on experiment design, preheat, consumable, cooling condition, preheat-cooling and preheat-consumable interactions were significant factors. Preheat is the most effective factor and in the case of E7018, preheat and cooling conditions were the most sensible factors. It was found that buttering was the most appropriate welding method for ferritic ductile cast iron.