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Preheating of work piece is essential in welding

Preheating of work piece is essential in welding Correct Answer Cast iron

Concept:

Preheating involves heating the base metal, either in its entirety or just the region surrounding the joint, to a specific desired temperature.

Preheating is often employed when welding cast iron, high carbon steel, or alloy steel since preheating slows down the cooling rate of that area of parent metal close to the weld itself and the weld itself and thereby prevents the formation of martensite which accounts for hardness across the weld.

The change of cracking in the heat-cooling is also minimized by preheating.

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