What is the lowest temperature that base metal can be for welding under AWS D1.1 standards?

In AWS D1.1, the minimum temperature for base metal before welding is typically established to ensure appropriate metallurgical properties and to prevent issues such as cracking during the welding process. The correct temperature threshold as specified in the code is 32°F. This is because at this temperature, the risk of brittle fracture increases for certain steels, particularly in certain heat-treated and high-strength steels.

By adhering to the requirement of having the base metal at or above 32°F prior to welding, welders can help minimize the likelihood of defects in the weld, preserving the integrity and strength of the joined materials. It is crucial for welders to understand the significance of this temperature to ensure that they are working under conditions that allow for effective and safe welding practices. This why 32°F is recognized as the critical temperature in the AWS D1.1 guidelines for welding operations involving steel.