Main measures to prevent welding spatter

The main disadvantage of CO2 gas shielded welding is welding spatter, which mainly adopts the following measures:

Correct selection of welding parameters

1.In CO2 gas shielded welding, the spatter rate and welding current of welding current and arc voltage have certain rules for each diameter of welding wire. The spatter is small in small current transition zone, and small in large current transition zone, but the spatter rate is large in the middle zone. The welding current zone with high spatter rate should be avoided, After determination, the welding current should match with the appropriate arc voltage.

2.The extension length of welding wire also has influence on welding spatter. If the diameter of welding wire is 1.2mm, the welding current is 280A, and the extension length increases from 20cm to 30cm, the welding spatter increases by 5%. The longer the extension length is, the greater the welding spatter is. Therefore, the extension length of welding wire should be shortened as far as possible.

Improve welding power

The main reason of welding spatter is in the final stage of short circuit transition. Due to the increase of short circuit current, the liquid bridge metal rises rapidly, resulting in heat accumulation and liquid bridge burst splash. Considering the improvement of welding power supply, the welding circuit adopts series reactor, resistance, current switching and current waveform control to reduce the liquid bridge burst current and reduce welding spatter.

Argon is added to the CO2 gas

After adding argon into CO2, the physical and chemical properties change. With the increase of argon ratio, the welding spatter decreases. The more significant change is the spatter with particle diameter greater than 0.8mm, but it has little effect on the spatter with particle diameter less than 0.8mm. The effect of argon on weld penetration, weld width and weld reinforcement decreases with the increase of argon content.

Use low spatter wire

On the premise of ensuring the mechanical properties of the joint, the carbon content of the solid cored wire can be reduced, and the alloy elements such as aluminum and titanium can be appropriately increased to reduce the welding spatter. The flux cored wire can reduce the welding spatter, and the welding spatter produced by the flux cored wire is one third of that of the solid cored wire.

Control of welding angle

When the welding torch is perpendicular to the weldment, the welding spatter is the smallest. The larger the inclination angle is, the more spatter is. When welding, the inclination angle of the welding torch should not exceed 20 º。