WELDING, CUTTING, AND BRAZING

Arc Welding and Cutting - Introduction

Shielding is one of the unique requirements of arc welding.

Experience has shown that welds will have better chemical and physical properties if the air can be kept away from the weld puddle. Such gases as oxygen, hydrogen, and nitrogen, along with water vapor (moisture) all tend to reduce the quality of the weld. Dirt, dust, and metal oxides (contaminants) also reduce the weld quality.

Shielding of the arc preserves the integrity of the weld joint. Shielding is provided either by:

Decomposition of the electrode covering, known as flux

A gas (or gas mixture) which may or may not be inert.

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