Slag is refers to the residual slag in weld metal, which is due to some non metallic inclusions in weld pool in the metallurgical process in the crystallization processto cannot float and remained inside the weld. Flux cored wire and submerged arc welding is easy to produce slag. Welding method, welding material production and slag (welding wire, flux) and the materials to be welded components about purity. Slag is mainly divided into the roots of slag, welding, seam welding slaglayer and the grain boundaries in slag.

1, not only harm: decrease in mechanical properties, but also increase thetendency of hot cracks, lamellar tearing induced plate.

2, reason: 1, the welding current is too small, the liquid metal and slaginseparable.

2, the welding speed is too fast, too late to float out of slag.

3, multilayer welding of the workpiece edge and weld cleaning not clean.

4, transport point of view is not correct.

3, prevent measures: correct select welding material (wire purity, flux), to control the content of parent material parathion, process should choose the appropriatewelding parameters, the molten pool exists time not too short. Multilayer welding,attention please except before welding slag, rightly, to slag to.