Control of special root incomplete fusion flaw produced by fibrin root welding;

The required performance of welding for corrosion resistant overlay on tube plate with no defects such as incomplete fusion and bead crack etc.

In order to prevent incomplete fusion,some measures should be adopted,such as using proper welding parameters,appropriate welding angle,assuring the swing range of electrode wire,confirming the welding layer number depending on the thickness of base metal and making multilayer and more bead as possible.

In order to overcome the decline of side-coupler under high-power pumping conditions,in which the index-matching materials cannot endure high-power light and will decompose,a novel method using CO2 laser to make fused side-coupler was introduced.

Based on the experiment,it analyses the cause of magnetic remnant appearing on groove of steel 980 ultra narrow gap GMAW in shipbuilding;when two different welding source,surface tension transition (STT) welding source and all-digital impulsion MIG/MAG(TPS5000) source are used,the magnetic remnant influences arc functional mode and bead sidewall fusion.