Effect of welding parameters on ferrite number of weld metal by E309L flux-cored wire

The effect of welding parameters on ferrite number（ FN） of weld metal by E309 L flux-cored wires were investigated through three methods of ferrite tester,Schaeffler diagram and WRC-1992 diagram. The results showed that change of FN in weld metal was the largest with the change of welding electric parameters,the gas flow was in the middle,and wire extension was the smallest. The FN in weld metal could be decreased by increasing wire extension and gas flow appropriately. The N element in weld metal was more sensitive to the change of gas flow and wire extension. WRC-1992 diagram was more accurate due to the consideration of N element,while the ferrite tester was suitable for FN under normal process parameters. With the increase of welding electric parameters,wire extension and gas flow,FN in weld metal measured with Schaeffler diagram decreased gradually.