Session: 03-05 Metals: Dissimilar Materials

Paper Number: 93916

93916 - Synergic Arc Additive Manufacturing of Graded Ferritic-Austenitic Transition Interface Materials for Welding Dissimilar Steels 

Dissimilar welding joints of creep strength enhanced ferritic/martensitic and austenitic stainless steels, which have been used extensively in fossil fuel and nuclear power generation plants, are susceptible to premature failure due to diffusive transformations in the as-welded microstructure that emerge during the service at high temperatures. The abrupt changes in fractions and consequently chemical potentials of alloying elements is a prime reason for such microstructural alterations, as well as the service temperatures. A hybrid plasma-metal arc welding torch was adapted for wire arc additive manufacturing with the capability to build ferritic-austenitic transition metals. Unlike conventional two-wire feedstock WAAM technique that exploits the unidirectional surface stress with direct current co-polarity at droplet/medium interface for mixing two wires, the hybrid plasma-metal arc technique provided smoother compositional grading due to the synergistically amplified Marangoni convection, which is induced by two arcs with different polarities. The spatial variations of chemical composition and metallographic observations were supported by tensile and creep tests in this present work. Evaluation of creep properties of dissimilar metal welds is critical to the structural integrity assessment. Graded ferritic-austenitic transition metal coupons built using this novel WAAM technique, synergic arc additive manufacturing, represented better creep parameters as compared to conventional dissimilar steel weldments.

Presenting Author: Koray Yurtisik Ion Industrial Metallurgy Research and Development Inc.

Presenting Author Biography: After receiving my master’s degree in Metallurgical and Materials Engineering, I worked as a non-destructive inspection engineer and 3rd party surveyor at various industrial manufacturing and construction sites worldwide. Meanwhile I received my International Welding Engineering diploma. Following my contributions in a fitness-for-service engineering assessment of a petrochemical plant as an engineer, I was employed by a leading corporate finance firm as an advisor on oil & gas industry in Turkey. In the following years, as the chief welding engineer at one of Turkey’s top three largest EPC contractors, I was responsible for the welding activities of industrial and civil infrastructures in both its fabrication halls and field sites. Then I was appointed as engineer in charge for the welding coordination of other companies in the group. Simultaneously, I started to give lectures in the welding engineering program at the university. Besides giving lectures, I was assigned to manage R&D and industrial projects at Welding Technology and Non-destructive Testing Research / Application Centre of the university where I completed my PhD studies and received the degree as well. Thanks to number of projects I was involved in, I have had the opportunity to utilize my metallurgical and welding engineering knowledge in the aerospace industry for the last couple of years. I am a founder of Ion Industrial Metallurgy R&D where we develop novel materials and processing technologies for aerospace and power generation industries. Ion IM R&D owns the only independent Nadcap material testing laboratory in Turkey.

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