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What are the three main zones formed around an arc weld?
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welding
Shielded metal arc welding.
When an arc weld is performed, the process creates three distinct zones in the surrounding metal due to the thermal effects of the welding arc:1
- Weld metal (fusion zone): This is the portion of the joint that was melted during the welding process. It typically consists of a mixture of the filler material and the base metal.1
- Heat-affected zone: This region is located adjacent to the weld metal. While it does not melt, it undergoes changes in its microstructure or mechanical properties because it is subjected to the heat generated by the welding process.1
- Unaffected zone: This is the base material that was not heated sufficiently during the welding process to alter its original properties.1