What are the precautions for the operation of electric welding flat welding position

1. Since the weld is in the horizontal position during welding and thedroplet is mainly transmitted by gravity according to the platethickness, larger welding current and thicker electrode can be usedfor welding.

2. Short arc welding is preferred

3. During welding, the included angle between the electrode and theweldment is 40°~ 90°. It is also necessary to control the arclength and strip conveying speed to separate the liquid metal fromthe slag and prevent the slag from flowing forward.

4. If the plate thickness is less than 5mm, generally, P3 or 4 weldingrod can be used for short arc welding. Do not shovel weld the rootbefore back sealing welding (except for important parts).

5. When horizontally welding inclined welds, uphill welding can be usedto avoid slag inclusion defects in the welds and prevent slag fromflowing to the front of the molten pool.

6. If multi-layer and multi pass welding is used, pay attention to theweld bead sequence and number.

7. For fillet, T-shaped and overlapped flat fillet welds, if thethickness of the two plates is different, the angle of the weldingrod needs to be adjusted to make the two plates heat evenly and makethe arc bias towards the thick plate.

8. Select the correct strip transportation mode.

(1) If the plate thickness is less than 5mm, 1-shaped groove butt weldingcan be adopted. In case of double-sided welding, the penetrationshall be greater than 2 / 38, and straight-line strip transportationshould be adopted for the front weld; The back weld shall also bestraight. The welding current shall be slightly larger than the gapon the front of the welding, and the speed of strip transportationshall be faster.

(2) Other grooves shall be made when the plate thickness is more than5mm. Butt welding, multi-layer welding or multi-layer and multi passwelding can be used. Bottom welding is suitable for small diameterelectrode, small welding current and straight-line strip welding. Thecovering weld and filler layer of multi-layer weld shall be linear,sawtooth, crescent, etc. according to the specific situation. Formulti-layer and multi pass welding, straight line should be adopted.

(3) When the weld leg size of T-joint is small, straight line, obliquering or sawtooth strip transportation can be adopted, andsingle-layer welding can be selected; When the weld leg size islarge, multi pass welding or multi-layer welding should be adopted.The backing welding adopts the straight-line strip transportationmethod, and then the oblique sawtooth or oblique ring striptransportation can be used for the welding of each layer. Formulti-layer and multi pass welding, it is best to use straight-linestrip welding.