Characterization of Microstructure, Strength, and Toughness of Dissimilar Weldments of Inconel 625 and Duplex Stainless Steel SAF 2205

Abstract

The dissimilar combinations of Inconel 625 and duplex stainless steel SAF 2205 obtained from manual GTA welding process employing ER2209 and ERNiCrMo-3 filler metals have been investigated. Formation of secondary phases at the HAZ of Inconel 625 and grain coarsening at the HAZ of SAF 2205 were witnessed while using these filler wires. The average hardness of ER2209 weldments was found to be greater than ERNiCrMo-3 weld. Tensile fracture was observed at the weld zones for both the fillers. Impact test trials showed brittle mode of fracture on employing ER2209 filler and mixed (ductile-brittle) mode of fracture while using ERNiCrMo-3 filler. Further optical microscopy and SEM/EDS analysis were carried out across the weldments to investigate the structure-property relationships.

Study on Microstructural Characterization, Mechanical Properties and Residual Stress of GTAW Dissimilar Joints of P91 and P22 Steels

“…The precipitation of Nb- and Mo-enriched Laves phase also increased the hardness of the weld metal. A similar observation has also been made by previous researchers [ 18 , 53 ].…”

Microstructural Analysis of Inconel 625 Nickel Alloy / UNS S31803 Duplex Stainless-Steel Dissimilar Weldments

“…Ni-based alloys are more expensive than stainless steels, and duplex stainless steels become more admirable and reliable candidate for replacement when compared to austenitic and ferritic stainless steels [3] Preferability of Ni-based alloys comes of their excellent characteristics such as; suitable yield, good tensile and creep strength and perfect corrosion resistance [2][3]. Duplex stainless steel is a less expensive material which brought down the cost without concession of the efficiency [6]. Dissimilar welds of Ni-based alloys and duplex stainless steels have substantial advantages in geothermal power plants, aeronautical, aerospace, chemical, off-shore and marine applications, steam generators, reformer and pyrolysis tubes in oil refineries.…”

“…Dissimilar welds of Ni-based alloys and duplex stainless steels have substantial advantages in geothermal power plants, aeronautical, aerospace, chemical, off-shore and marine applications, steam generators, reformer and pyrolysis tubes in oil refineries. In addition, these dissimilar welds are used in sensitive industries for heavy duty operations such as petrochemical factories, acid production plants and nuclear power plants, where a combination of the high mechanical strength and high corrosion resistance is required [1][2][3][4][5][6]. Dissimilar welding of Ni-based super alloys with stainless steel has some difficulties such as ductility-dip cracking (which occurs during the multi-pass welding of Inconel 625), hydrogen cracking (cold cracks) and brittle phases in the fusion and heat affected zone of the weld which may lead to poor mechanical and metallurgical characteristics [7].…”

Nikel Bazlı Süper Alaşım Inconel 625 ile AISI 304L Paslanmaz Çelik Malzeme Çiftinin Birleştirilmesinde Farklı İlave Metallerin Tokluk ve Mikroyapısal Özelliklere Etkisi

“…[1] Korrapati P.K., Avasarala V.K., Bhushan M., Ramkumar K.D., Arivazhagan N., Narayanan S., Assessment of Mechanical properties of PCGTA weldments of Inconel 625, Procedia Engineering, 75, (2014 ), [9][10][11][12][13]…”

“…304L tarafında ise ergime sınırı boyunca tane sınırı kalınlaşması mevcut olup ostenitik paslanmaz çeliklerin yapısı gereği tane büyümesi bulunmamaktadır. Kaynak metali mikroyapısı daha açık tonda görülen dendritler arasındaki Nb ve Mo gibi ağır metallerin segregasyonunda dolayı, koyu dendtritik ağ ters ışınımlı elektron mikroskobunda daha açıkça görülür(13).…”