How to reduce spatter when welding

The main factor of welding spatter is the disadvantage of CO2 gas shielded welding. At present, the following measures are mainly taken to reduce the spatter of CO2 gas shielded welding:

Correct selection of welding parameters:

(1) In CO2 gas shielded welding, there is a certain law between welding current and arc voltage for each diameter of welding wire. Entering the transition zone of high current fine particles, the welding spatter rate is small; The splash rate is small after the small current short-circuit transition zone; The welding spatter rate in the middle zone is the largest. Take the welding wire with diameter of 1. Take 1.2mm as an example. If the welding current is greater than 300A or less than 150A, the welding spatter is small; If the value is between this area, the welding spatter is large. When operating the welding current, match the appropriate arc voltage after determining the welding current to avoid the welding current area with high welding spatter rate.

(2) The extension length of welding wire is: the extension length of welding wire (i.e. dry elongation) also has an impact on welding spatter. The longer the extension length of welding wire, the greater the welding spatter. For example, when the wire diameter is 1. 2mmhas 280A welding current. When the extension length of welding wire increases from 20mm to 30mm, the spatter will increase by about 5%.Therefore, it is required to shorten the extension length of welding wire as much as possible

Improve welding power supply:

The main cause of spatter in CO2 gas shielded welding is that in the last stage of short-circuit transition, due to the rapid heating of liquid bridge metal, the short-circuit current increases sharply, resulting in heat accumulation and finally liquid bridge burst and spatter.From the perspective of improving welding power supply, several methods are mainly adopted, such as series reactor and resistance in welding circuit, current switching, current waveform control and soon. To reduce the burst current of the liquid bridge, so as to reduce the welding spatter

Add argon to CO2 gas

Adding argon to CO2 will change the properties of CO2. With the increase of argon, the welding spatter decreases gradually. The most significant change in splash loss is splash with particle diameter greater than0.8 mm. However, it has little effect on splash with particle size less than 0.8mm.

In addition, adding argon mixture to CO2 gas can improve weld formation.The effect of adding argon into CO2 gas on weld penetration, weld width and reinforcement changes with the increase of argon content inCO2 gas.