TWI Industrial Member Report Summary 173/1982
By G A Hutt and W Lucas
The literature relating to the problems of variability in the welding behaviour of different batches of material is reviewed for arc welding processes involving metal transfer.
A previous review concerning cast to cast material variations in TIG welding emphasised the lack of agreement as to the causes of the variations in the penetration and fusion zone geometry observed when welding certain sheet and tube materials.
In consumable electrode arc welding a similar situation exists but here the pmblems arise from the electrode wire material as well as the component material and are characterised by the breakdown of stable metal transfer and inferior weld quality.
In the case of steels this behaviour appears to be linked with minor compositional differences between batches of material and inclusions in the steel whereas with aluminium alloys the presence of volatile alloying elements in the electrode wire is considered to be responsible for arc instabilities.