L51926 Effects of Welding on HAZ Softening of X70-X80 TMCP Linepipe Steels

Experimental work was done to evaluate the effects of welding on the hardness, tensile and toughness properties of the heat affected zone (HAZ) of a series of commercial high strength micro-alloyed linepipe steels, produced through controlled rolling and accelerated cooling (thermo-mechanical control process - TMCP). The test materials, representative of modern low carbon linepipe steels, were selected such as to cover a broad range of chemistries (alloy /micro-alloy designs) and mechanical properties (X 70 and X 80).