This study investigated the microstructure of the dissimilar metal welding of Inconel 625 and AISI 316L using Continuous Current Gas Tungsten Arc Welding (CCGTAW) and Pulsed Current Gas Tungsten Arc Welding (PCGTAW) processes with ERNiCr-3, TIG 316L and twisted (ERNiCr-3 and TIG 316L) fillers. Microstructure examinations were carried out using an optical microscope and Scanning Electron Microscopy (SEM)/Energy Dispersive X-Ray (EDAX). The results of the study showed the existence of a partially melted zone (PMZ) on the AISI 316L side. Weld zone (WZ) analysis showed the existence of a multi-directional grain growth on the 316L side in all specimens, although less growth was found on the Inconel 625 side. Grain growth almost disappeared using PCGTAW with twisted fillers. SEM/EDAX investigations indicated that secondary deleterious secondary phases were tiny and white in five experiments. However, a meager amount of precipitates occurred in PCGTA welding with twisted fillers. Moreover, these were particularly innocent precipitates, represented by black dots in images, whereas other tiny white secondary phases are known to be brittle. As a result, PCGTA welding with twisted fillers exhibited the best metallurgical properties.

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Rotary kilns have widespread usage in many field of industry due to continues flow and heating the products inside it, simultaneously. Rotary kiln can be used in the process of alumina, cement, lime, magnesium etc. Rotary kiln material for corrosive process media is usually designated as stainless steel. In some media as high temperature and dilute acidic, even stainless steel can be subject to rapid corrosion. In this study, an alternative material, titanium Gr 2, was investigated instead of conventional 316L (1.4404) quality stainless steel material of rotary kiln. Due to the different physical properties of titanium Gr 2 material, two different alternative designs were prepared and analyzed with the model. In the first design the outside of the titanium shell of the rotary kiln was covered with 316L (1.4404) quality steel material. In this design, different thermal expansion of the materials limited the usage of hybrid materials at high temperature. Therefore, as a second alternative the length of the rotary kiln was extended. According to required product output temperature the required of the length extension was calculated as 4600 mm.