Development of Tack Welding Procedures using the TIG Process

TWI Industrial Member Report Summary 511/1995

F J Blunt

Scope

In response to a perceived need for a device to tack together plates prior to welding, preliminary trials have been undertaken to establish the feasibility of using the TIG welding process for melting of TIG rod into suitable joint preparations in C-Mn steel plate. Particular attention has been paid to inspection for defects, and the behaviour of unrestrained rod under welding conditions.

Objectives

The aims of this project were:

• To establish the feasibility of producing tack welds by fusing short lengths of TIG rod, using TIG welding.
• To define a range of arc energy suitable for the fusion of TIG rod, in the diameter range 1.6 to 3.2 mm, to plate, into fillet welds, and butt welds.
• To determine the effect of varying the root gap in fillet and butt joints. To determine the effect of varying torch angle on leg length in fillet welds.
• To examine the tack welds for defects.
  

The work was confined to a study of welds on clean C-Mn steel.