Arc ignition of CWW CO₂ welding in A36 steel

ABSTRACT

In gas metal arc welding, arc ignition significantly influences arc stability, droplet transfer, and the quality of welded joints. Cable-type welding wire (CWW) CO₂ welding is an innovative welding method. This paper analyzes the arc ignition procedure for this type of welding based on experiments with three different wire end conditions: an unsmooth wire end, a smooth wire end, and a preheated smooth wire end. Smaller contact areas between the CWW and the workpiece led to higher arc ignition currents, and higher wire tip temperatures led to shorter arc ignition times (AITs) with the same chemical composition, diameter, and extension. Based on the characteristics of the welding wire end structures and the contact resistance between the CWW and workpiece, a suitable mathematical model of the AIT was developed. The model was validated using experimental arc ignition images. The AITs for the unsmooth smooth and preheated smooth wire ends were 14, 20, and 11 ms, respectively, essentially consistent with the model calculations.

KEYWORDS:

• Arc
• cable type
• CO₂
• end
• ignition
• images
• time
• welding
• wire

Additional information

Funding

This work was supported by the National Science Foundation of China (grant no. 51275224 and no. 51575250), the Province Joint Research Project of Jiangsu Province of China (grant no. BY2015065-06), the Collaborative Innovation Center of Ship Technology of China (grant no. HZ20160020) and the Priority Academic Program Development of Jiangsu Higher Education Institutions of China.