Studies on microstructure, mechanical and pitting corrosion behaviour of similar and dissimilar stainless steel gas tungsten arc welds

International Conference on Recent Advances in Materials, Mechanical and Civil Engineering

材料科学;机械制造;土木建筑工程

Mohammed, Raffi^1 ; Dilkush^2 ; Srinivasa Rao, K.^3 ; Madhusudhan Reddy, G.^4

Department of Metallurgical and Materials Engineering, NIT, Andhra Pradesh, India^1

Department of Metallurgical and Materials Engineering, RGUKT, Nuzvid, India^2

Department of Metallurgical Engineering, Andhra University, Visakhapatnam, India^3

Defence Metallurgical Research Laboratory, Hyderabad, India^4

关键词: Dissimilar stainless steels;    Duplex stainless steel;    Duplex stainless steel welds;    Filler wire composition;    Gas tungsten arc welding process;    Gas tungsten arc welds;    Microstructural changes;    Microstructural variation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/330/1/012028/pdf
DOI  :  10.1088/1757-899X/330/1/012028

来源: IOP

【 摘 要 】

In the present study, an attempt has been made to weld dissimilar alloys of 5mm thick plates i.e., austenitic stainless steel (316L) and duplex stainless steel (2205) and compared with that of similar welds. Welds are made with conventional gas tungsten arc welding (GTAW) process with two different filler wires namely i.e., 309L and 2209. Welds were characterized using optical microscopy to observe the microstructural changes and correlate with mechanical properties using hardness, tensile and impact testing. Potentio-dynamic polarization studies were carried out to observe the pitting corrosion behaviour in different regions of the welds. Results of the present study established that change in filler wire composition resulted in microstructural variation in all the welds with different morphology of ferrite and austenite. Welds made with 2209 filler showed plate like widmanstatten austenite (WA) nucleated at grain boundaries. Compared to similar stainless steel welds inferior mechanical properties was observed in dissimilar stainless steel welds. Pitting corrosion resistance is observed to be low for dissimilar stainless steel welds when compared to similar stainless steel welds. Overall study showed that similar duplex stainless steel welds having favorable microstructure and resulted in better mechanical properties and corrosion resistance. Relatively dissimilar stainless steel welds made with 309L filler obtained optimum combination of mechanical properties and pitting corrosion resistance when compared to 2209 filler and is recommended for industrial practice.