What is the minimum preheat temperature for ASTM A606 when welding with 9018 electrodes on 2" thick steel?

The correct minimum preheat temperature for ASTM A606 when welding with 9018 electrodes on 2" thick steel is indeed 150°F. This preheat temperature is important because it helps to reduce the risk of cracking in the heat-affected zone (HAZ) and improves the mechanical properties of the weld.

Preheating is often required for high-strength low-alloy steels like ASTM A606, especially when dealing with thicker materials. This process allows for better control of the cooling rates and mitigates the formation of hard brittle martensite in the weld area which can occur due to rapid cooling.

Specific preheat requirements are detailed in both the AWS D1.1 code and associated tables that guide welders on proper welding practices for different materials and thicknesses. Following the specified minimum preheat temperature ensures compliance with these guidelines and ultimately contributes to a sound weld.

When the preheat temperature is set correctly, the potential for defects such as cracking is significantly minimized, which is essential for maintaining the structural integrity of welded components in engineering applications.