Investigating the Effects of Heat Input on Corrosion Rate of Joint of Duplex Stainless Steel 2205 Weldments by GTAW Process

Duplex stainless steels has had a variety of usage in the chemical، petrochemical، oil and gas industries because of the adequate mechanical properties and high corrosion resistance. In this article، corrosion rate and mechanical properties of welded duplex stainless steel (2205) has been analyzed using for different heat input of 0. 86، 0. 91، 1. 02، 1. 12 kJ/mm. welding process carried out using reverse Pole GTAW process. The corrosion resistance in 3. 5% of NaCl solution was evaluated by potentiodynamic polarization tests for weld deposit and heat affected zone (HAZ) at room temperature. The results indicated that for heat input 1. 12، 1. 02، 0. 91، 0. 86 kJ/mm the corrosion rate are 0. 230، 0. 004، 0. 009، and 0. 034 (mm/yr) respectively. Decreasing the heat input causes the ferrite volume content of weld deposit of the samples to increase which the correspondence between the theoretical and experimental results of this article has been indicated by studying the effects of this parameter on the corrosion rate and mechanical properties. The sample No. 1 having Max. Heat input possesses Max. Corrosion rate. The results also show that the sample No. 2 with heat input of 1. 02 kJ/mm، have an optimum condition of corrosion rate and creating proper mechanical properties for welding the 2205 stainless steel.