How does preheating affect welding of high carbon steels with GTAW?

How does preheating affect welding of high carbon steels with GTAW?

• A. Preheating has no effect on high carbon steel.
• B. Preheating reduces thermal gradient and cracking risk, improves ductility, and controls cooling rate; excessive preheating can cause grain growth and distortion.
• C. Preheating always eliminates distortion.
• D. Preheating increases hardness of base metal.

Answer: (B)