Han goc (E)

Subject Fillet welding in flat position 1 1. Finished image 2. Materials (1) The size of materials (2) Welding materials 2. The shape of welding joint 3. Tack welding and its position (1) Tack welding condition Tack welding current A Arc voltage V CO 2 flow rate l/min Crater filler switch Off 2 3 (2) How to do tack welding 4 ■Hold materials as “V” and do tack welding at both ends by jig to fix materials. ■ T he n lay 2 tack welding beads as shown in the above figure. (2) The start of welding (3) Aiming of the wire tip 5 ■G enera te the arc at 10 ～ 20 mm from starting point and return to the starting point quickly. ■Aim the wire tip at root of welding joint and do not lean the torch to each side of materials. (5) Treatment of the welding end of the first layer ■ Return to the starting point about 5 ～ 10 mm at the welding end slowly or generate the arc intermittently at the welding end and bury the melting wire at crater. ■ After welding, clean and check a bead. 6 ■ Keep the wire tip at leading end of the molten pool. ■ Push the torch during observing the melting of both sides of material evenly. 5. Welding of the second layer with one pass by backhand welding with weaving motion (1) Welding condition Welding current A Crater filler switch Off ・ On Arc voltage V Crater current A CO 2 flow rate l/min Arc voltage V (2) The start of welding (3) The point of welding the second layer P: Pitch of weaving 7 ■ Gener ate the arc at 10 ～ 20 mm from starting point and return to the starting point quickly. Backhand welding is the opposite direction of forehand welding. Next aiming of the arc: ■ Melt the triangle zone with the leading end of the molten pool and each side of material. ■ Weld the second later about 1 mm low from the both edge of material. 8 Next aiming of the arc:　 　 ■ Move the wire tip from side to side and stop it for a short moment (One breath) at each side. (4) Treatment of the welding end of the second layer is the opposite of the first layer. 6. Welding the final layer with one pass by backhand welding with weaving motion. (1) Welding condition Welding current A Crater filler switch Off ・ On Arc voltage V Crater current A CO 2 flow rate l/min Arc voltage V (2) The start of welding is the same to the second layer. (3) The point of welding of the final layer ■ Ai m the wire tip(arc) at the leading end of the molten pool. ■ Move the wire tip at the leading end of the molten pool and pass the arc quickly at center of the molten pool. ■ Observe the enlarging the molten pool by both edge of material. 9 Next aiming of the arc: ■ Move the arc by both edge of material and stop it for a short moment (One breath) at each side. ■ Melt the triangle zone with the leading end of the molten pool and each side of material. Next aiming of the arc: ■ Melt the triangle zone with the leading end of the molten pool and each side of material. ■ Do not melt too much at both edge of material. (4) Treatment of the welding end of the final layer is the same to the second layer. 10 . point and return to the starting point quickly. Backhand welding is the opposite direction of forehand welding. Next aiming of the arc: ■ Melt the triangle. sides of material evenly. 5. Welding of the second layer with one pass by backhand welding with weaving motion (1) Welding condition Welding current A Crater