Friction Stir Welding of Low-Carbon Steel
The present study focused on the Friction stir welding (FSW) of 4-mm-thick plate of low-carbon steel at different welding conditions. FSW tool made up of tungsten carbide alloy (WC-10wt.% Co) was used to perform the welds at the rotational speeds of 300 rpm and 600 rpm at a constant welding speed of 132 mm/min. The welding was carried out along the rolling direction in the butt joint configuration. Joint was characterized in respect of microstructure, tensile strength, and microhardness. Transient thermal history was recorded using K-type thermocouples during the welding. Microhardness values were higher in the weld zones than the base material. Peak hardness values were observed in the stir zone, which were decreasing on moving toward the base material. Welded sample failed in the base material and demonstrated comparably higher yield and ultimate tensile strength than the base material. However, the ductility of the weld joints was reduced as compared to the base material. Surface roughness measurement was carried out which confirmed more twear at the tool pin than the tool shoulder. From the results, it is concluded that FSW can produce successful welds in low-carbon steel with higher tensile strength and hardness values than the base material.
KeywordsLow-carbon steel WC-10 wt.%Co alloy Tensile properties Microhardness Surface roughness
The authors thankfully acknowledge the funding and support provided by the Naval Research Board (NRB), Government of India. The authors are also grateful to the Management and Mechanical Engineering Department, Indian Institute of Technology Guwahati (IITG), Guwahati, India. The authors are also thankful to the Central Instruments Facility of IITG for providing the required research facilities.
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