Effect of welding processes and conditions on the microstructure, mechanical properties and corrosion resistance of duplex stainless steel weldments-A review

Dual phase duplex stainless steel comprised with ferrite and austenite shows its strength and corrosion resistance in many aggressive environments based on outstanding performance over the last 20 years establishment is a great attention for researchers, manufacturers and end users. The current worldwide rapid growth, demand, and consumption of duplex-stainless steels, particularly in petrochemical, marine, power plant and other engineering applications, where the multiphase steels are being utilized that require welding for fabrication of components. On the other hand, largest production and applications sectors are captured by austenitic stainless steels globally, but the Ni price volatility breaching the backbone of producers and end users. In such conditions for the cost flexibility, joining of dissimilar metals also reflects the overall industrial need. Joining of duplex alloys is a challenging, due to number of embrittling precipitates and metallurgical changes. On the other hand inappropriate welding conditions, imbalance phase ratio of austenite/ferrite leads to solidification cracking, corrosion susceptibility, and lower ductility. As the demand for higher productivity is increasing worldwide in many domains like oil pipeline, shipbuilding sectors etc., where the thick sections are used, which endorses the requirement of higher heat input, optimization of interpass temperature, cooling rate, proper selection of consumables, defect free joints for fast and rapid productivity. However, many advanced techniques like plasma, laser, PCGTAW, A-TIG and hybrid welding processes are developing to fulfill the requirements for higher productivity without distortion. But high ferritization is another issue with those processes. Moreover, suitability and standardization of duplex alloys for high current and large heat input are still in doubt. Even, no comprehensive accounts of the dissimilar welding operation on the effect of processes and welding conditions are found in the literature. This review paper systematically highlights the effect of welding processes and conditions on microstructure, mechanical properties and corrosion resistance of duplex stainless steels and its various combinations on the basis of structure-property co-relationship. (C) 2016 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.