Influence of Wire Feeding Speed, Welding Speed and Preheating Temperature on Hardness and Microstructure of Weld in RQT 701-british Steel Produced by FCAW

FCAW (flux-cored arc welding) is an arc welding process widely used in different industries to join the metals and alloys. The present study focuses on the effect of FCAW-G process parameters on the hardness and microstructure of weld in RQT 701-British steel having 5 mm thickness. In this study, effects of wire feeding speed, welding speed and preheating temperature were investigated. Different samples were produced by employing wire feeding speed of 4.5, 6 and 7.5 m/min, welding speed of 30, 45 and 60 cm/min and preheating temperature of 200, 300 and 400°C. After welding process, brinel hardness (HB) test was performed on weld metal and the micro-structural evolution of weld was analyzed by optical observations of the weld cross sections. Results were clearly illustrated that change in process variables has significant effect on hardness, grain size and phases transformations in weld metal.