A review on welding of high strength oil and gas pipeline steels

Mechanical Properties of High-Nb X80 Steel Weld Pipes for the Second West-to-East Gas Transmission Pipeline Project

“…The microstructure and mechanical properties of the HAZ are strongly related to the welding heat input and chemical composition of the steels [14,16]. Because the similar welding process parameters are adopted for the same size pipe manufactured in the mill, the chemical compositions of the pipeline steels become one of the most important factors to affect the mechanical properties of HAZ [14].…”

“…The microstructure and mechanical properties of the HAZ are strongly related to the welding heat input and chemical composition of the steels [14,16]. Because the similar welding process parameters are adopted for the same size pipe manufactured in the mill, the chemical compositions of the pipeline steels become one of the most important factors to affect the mechanical properties of HAZ [14]. For the high-Nb X80 steels with high-Nb and bearing Ti, the prior austenite grain Advances in Materials Science and Engineering 11 in HAZ has lower coarse tendency, because the (TiNb)(CN) precipitates are not completely dissolved during the thermal cycle [20].…”

“…However, it is not only the toughness but also the strength that has great effect on the integrality and operation safety of pipeline [14,24]. Therefore, optimizing the amount of the alloying elements for the high-Nb X80 pipeline steels needs to overall consider the effects on strength and toughness.…”

“…Hence, how to control the mechanical properties of HAZ becomes one of key issues in the researches of pipeline steel. The microstructure and mechanical properties of HAZ strongly depend on chemical composition of the steel and welding parameters [14,15]. For the same size steel pipe, the similar welding parameters are generally used in a plant.…”

FE Analysis of Temperature Field in a Twin-wire Tandem Submerged Arc Welded X80 Steel Pipe

“…API X80 pipeline steel with yield strength greater than 555 MPa is the promising grade for today's need of pipeline industry. In comparison with X70 grade pipeline, X80 grade pipeline represents approximately 12 % reduction in total steel weight and up to 25% less deposited weld metal [1][2][3]. These high strength linepipes are usually manufactured by submerged arc welding in the practical application.…”