Effect of Groove Design on the Mechanical Properties of Shielded Metal Arc Welded Joints

Abstract

Objective: To investigate the effects of groove angle on tensile and impact strength of the joints. Methods: To achieve above objective various groove designs having included angle of 50°, 60° and 70° were prepared using a shaper. The weld grooves were completely filled using shielded metal arc welding process. All the weld joints were subjected to visual inspection, dye penetration test and radiographic test. Then tensile and impact specimens were removed from these joints. The tensile and impact specimens were machined in accordance with ASTM E8M-09 and ASTM E23-12C specifications. The tensile and impact strength was evaluated using universal testing machine. Findings: The tensile strength of the specimen having groove angle as 50° is 513.68 MPa which is more than that of the specimen having 60° and 70° groove angle. The tensile strength of base material used is 540 MPa. It is clear that the tensile of the joint is less than base material used. The joint efficiency obtained is 95.12% which is the highest compared with other joint i.e. 60° and 70°. It is further observed maximum impact strength achieved is 53.45 Joule at 50° groove angle. The tensile and impact strength provided by the joint having groove angle as 70° is 471.29 MPa and 39.15 J respectively which is minimum amongst all the joints produced.It can be concluded that 50° groove angle is the best groove design. Moreover less number of welding electrodes is required to fill this joint compared with 60° or 70° groove angle. Hence it is more economical also. Application: This research is useful for industries which are engaged in fabrication work for designing of correct and economical welding grooves. Keywords: Groove Design, Impact Strength, Radiography, Shielded Metal Arc Welding, Tensile Strength