Alloy pipes generally need to be welded with other steel materials to fully exert their effectiveness.

Alloy pipes don't demand particularly high welding standards, but the weld must be seamless and perfect. Preheating is required for alloy pipes at temperatures not too high, so when should preheating occur given the surrounding temperature?

Welding requirements for alloy pipes are not stringent; the environmental temperature must not be below 5℃. If it is lower, consider increasing the environmental temperature. Generally, preheating is necessary for weld quality assurance when the plate thickness is above 20mm or the carbon equivalent is high.

Preheating is not about the surrounding environment's temperature; it's about the board thickness and carbon equivalent.