Determination of the optimum conditions of melting of filler wire in automatic orbital welding of steel pipelines

Abstract

A physical–mathematical model of melting of wire in TIG welding has been developed for the determination of the maximum permissible values of the wire feed rate in orbital non-consumable electrode welding and for preventing the formation of lack of fusion defects at the edges or between the layers. The criterion of the optimum wire feed rate is the ratio between the wire feed rate, the power and the diameter of the arc jet resulting in stable melting of the wire. Modelling of the process of formation of the welded joint confirms the efficiency of the proposed criterion.

Keywords:

• pipeline
• compressor station
• non-consumable electrode
• orbital welding
• additional wire
• welded joint
• weld pool