ESSC & DUPLEX 2019

Dual phase duplex stainless steel comprised with ferrite and austenite performance shows its strength and corrosion resistance in many aggressive environments based on outstanding performance in the last years. The current worldwide rapid growth, demand, and consumption of duplex stainless steel, particularly in petrochemical, marine, power plant, food industry and other engineering application, where the multiphase steels are being utilized that require welding for fabrication components. Joining of duplex alloys is a challenging, due to number of embrittling precipitates and metallurgical changes. Generally, the quality of a weld joint is strongly influenced by parameters during welding process; inappropriate welding conditions and imbalance phase ratio of austenite/ferrite leads to solidification cracking, corrosion susceptibility, and lower ductility. To achieve high quality welds mathematical models that can predict the bead geometry for obtaining the desired mechanical properties of the weldment has been developed. This paper focuses on determining the percentage of ferrite in GMAW welds of duplex stainless steel SAF 2205. Previously established models for the prediction of weld bead geometry were applied. The values of weld penetration and reinforcement were calculated using statistical approach and applying the rule of mixture, and using the Schaeffler diagram. The amounts of ferrite in the duplex stainless steel welds were determined and compared with experimentally-determined ones. The results show that the developed models for predicting weld bead geometry can also be applied to estimate the percentage of ferrite in the duplex stainless steel weldments.