Monitoring workpiece heat with a temperature indicator stick can minimize warping and weld cracking and reduce the need for gages or electronic devices. Whether roasting the Sunday turkey or preheating an aluminum workpiece, maintaining the required temperature is critical to a successful procedure. A welder preheats the workpiece prior to welding, brazing, or cutting, according to the American Welding Society Welding Handbook, for three reasons: To equalize the temperature of the workpiece minimize warping/distortion or possible rupture of a weldment. To reduce the amount of heat needed to make a weld or braze. To prevent hardening and cracking when a part is cooled too rapidly through the transformation range, particularly for cast iron and most carbon steels. A smaller temperature differential reduces the heat flow from theweld area and slows the cooling rate.
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