Welded steel pipe weld slag

Welded steel pipe weld slag

After welding, the weld slag residue called slag, slag impact on the performance of the joint is relatively large. Slag because most irregular shape, will reduce the weld ductility and toughness, it will cause a lot of stress in sharp focus, sharp apex often leads to cracks, weld needle phosphide oxides and slag will weld metal brittle, reducing mechanical properties, easy slag iron oxide and sulfide iron clamp weld brittle.

Causes

Bevel angle is too small, the welding current is too small, too large, such as slag viscosity, less slag floating slag bath surface is formed. At the same time the following reasons:①multi-pass welding time, every weld slag removal is not clean, not completely;②electrode coating to block off not melt;

Preventive measures:

The groove and the weld slag layer between the clean, the bump at the leveled; appropriately increasing the welding current, the arc is shortened, if necessary, and to increase the residence time of the arc, the molten metal and slag to be fully heated; according to molten situation, any time to adjust the angle and transport bar electrode method that can float to the molten slag surface; the correct choice of chemical composition of the base material and welding of metals, reduce the melting point and viscosity of the slag to prevent slag produced.