The effect of microsilica on the microstructure and residual strain of the welded zone in ST35 steel
Subject Areas : Telecommunication
1 - Department of Engineering, Semnan Branch, Islamic Azad University, Semnan, Iran.
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Abstract :
Welding of an alloy can be evaluated as appropriate when the properties of the welded area are most similar to the base metal. In the present study, to perform the welding process, first, ST35 steel plates were prepared and cut to dimensions of 5×10 cm. Then, the welding area was beveled at an angle of 45 degrees and filled with microferro-silica material in weight amounts of 0.5, 1, 1.5, 2 and 2.5 grams. Subsequently, the welding process was used to connect the parts to each other by the hand electrode method and in gravity mode. To evaluate the properties of the welded area, the samples were cut with a band saw machine to dimensions of 1×3 cm along the perpendicular to the weld seam section. The microstructure of the cut section was examined by scanning electron microscope (SEM). The residual strain in the welding sections of different samples was also obtained using X-ray diffraction (XRD) and Williamson-Hall analysis method. The results of the studies showed that with increasing the amount of microsilica, the grain size of the welding zone becomes finer. It was also observed that with increasing the percentage of microsilica up to 2%, the size of ferrite crystals increases, which indicates the growth of crystals under the influence of the presence of microsilica up to 2%.