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Engineering Journal:: March 2017 Issue

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The Effect of welding method and heat treatment on creep resistance of Inconel 718 sheet weldsAbstract The paper presents results of a study on the effect of welding technique and heat treatment on structure and creep resistance of welded joints made on thin (0.5–1.2 mm) Inconel 718 sheet with the use of GTAW and laser method without filler metal. Technological high-temperature creep tests consisted in measuring the time to rupture for sheet metal without and with welded joints under constant stress σ = 150 MPa and at constant temperature tc = (860 ± 2)°C.Sheet metal joints made with the use of GTAW method and laser-welded are characterized with a three-zone macrostructure, including the weld with size of dendritic grains depending on welding method, the heat-affected zone (HAZ), and the base material (BM). For GTAW method, with increasing sheet metal thickness, the observed values of parameter λ2s (distance between axes of second-order branches of dendritic grains) decrease from abo…