Creep and Oxidation Behavior of GTAW Welded ET45 Micro Alloy Tube

摘要: Ethylene pyrolysis furnace tubes are subjected to a variety of failure mechanisms such as creep, oxidation, carburization, and thermal shock. Therefore, proper selection of filler metal and welding process is important in their repair process. In this work, the effect of UTP 2535 Nb and UTP 3545 Nb filler metals on the microstructure, creep behavior, and oxidation resistance of Gas Tungsten Arc WeldedET45 Micro alloy tube is investigated. Based on the results, the microstructure of the joint welded with UTP 2535 Nb filler metal is composed of Chromium and Niobium carbides deposited along the dendritic grain boundaries of the austenitic matrix. The joint welded with UTP 3545Nb filler showed a similar structure, except for denser and more continuous carbides. Compared to the base metal, the weld zone of both samples showed higher hardness values which can be explained by the finer grain size and continuous …