Fluxes for MMA electrodes
Role of flux
- to stabilise the arc and make it easy to strike
- to provide a gas shield
- to provide a slag which protects the weld pool
- to provide extra alloying elements to the weld pool
Main types
- cellulosic - high volume of gas, fast welding but high level of hydrogen
- basic (calcium carbonate) - CO2 gas shield produced and basic slag, low hydrogen if kept dry
- rutile - mixture of TiO2, hydrated minerals and cellulose, high hydrogen content