Fabrication of thick multilayered steel structure using A516 Grade 70 by multipass friction stir welding

Abstract

In the present work, a thick-sectioned multilayered steel structure was fabricated by multipass friction stir welding on A516 Grade 70 steel. Tensile strength of the multilayered samples was comparable to that of the base metal. Failure was located in the base metal when a defect-free sample was tested. Charpy impact toughness was higher in the stir zone and heat affected zone than in the base metal. Higher microhardness values were found in the stir zone and heat affected zone than the base metal due to grain refinement and modification of the microstructures. Consequently, improved mechanical properties compared to the base metal were found in the weld zones of friction stir welded A516 Grade 70 steel.

Effect of Different Cycles of Thermal Fatigue in Steel Metallurgical Aspects ASTM SA-516 Grade 60

“…The microstructure of SA-516 grade 60 steel contained ferrite and perlite phases. This microstructure being typical of hypo eutectoid steels (Gong et al, 2010;Lim et al, 2016). The ASTM grain size in the sample as received, using the grain count by the intercept method.…”

“…Some properties of SA-516 steel, on the microstructure in the zone affected by heat (HAZ), equiaxial ferrite grains and small pearlite colonies, occurs. With grains considerably refined, due to the partial transformation of austenite within the intercritical temperature region, between A1 and A3, the material has been exposed to this region for insufficient time for a complete transformation of austenite, leading to the formation of perlite colonies on ferrite, during cooling (Araújo et al, 2015;Lim et al, 2016).…”

“…Higher values of microhardness happen in the HAZ, due to the grain refining and the change of the microstructure, consequently, improving the mechanical property compared to the substrate cooling (Lim et al, 2016).…”

Investigation of Nondestructive Testing Methods for Friction Stir Welding

“…This process works by joining metals layer-by-layer until the desired shape and thickness of the part is achieved [31,32]. The advantage of this method is that each previously added layer acts as a support for the next pass so that the structure is self-supported during the manufacturing process [32,33]. Investigations show that mechanical properties of multilayer FSW formed materials are comparable to those of the corresponding base metal.…”

“…Investigations show that mechanical properties of multilayer FSW formed materials are comparable to those of the corresponding base metal. In addition, there are potentially improved mechanical properties in the weld zone' when compared to those for the base metal [32].…”