What is the recommended preheat temperature for welding ASTM A285 C grade

The recommended preheat temperature for welding ASTM A285 C grade steel depends on several factors, including the thickness of the material and the welding process being used. In general, a preheat temperature in the range of 200-400°F (93-204℃) is commonly recommended.

For thicker sections of ASTM A285 C grade, a higher preheat temperature may be necessary to ensure proper fusion and prevent cracking. In some cases, a differential preheat may be required, where the base metal is preheated to a higher temperature than the weld metal.

It's important to consult the welding procedure specification (WPS) provided by the manufacturer or an experienced welding engineer when determining the appropriate preheat temperature. The WPS will provide guidance on the specific preheat temperature, as well as other variables such as preheat time, interpass temperature, and post-weld heat treatment.

Additionally, it's crucial to follow proper welding techniques and practices, such as using appropriate filler metals, maintaining proper weld bead size and shape, and controlling the cooling rate after welding, to ensure the quality and integrity of the finished weld.