Control of Softening Processes in the Heat-Affected Zone During Welding of High-Strength Steels

Abstract

The hardness and the structure of the heat-affected zone (HAZ) under welding of tube steels of strength category K60 – K70 are studied. The steels are treated by regimes imitating the thermal cycles of different welding processes applied to tubes starting with manual arc welding and ending with energy-intensive automatic submerged-arc welding. The welding modes causing maximum decrease in the hardness of HAZ regions are determined. The conditions preventing softening under one-pass and multipass welding of high-strength steels are presented.