Challenges and developments in pipeline weldability and mechanical properties

Abstract

Recent economic and political events have further highlighted the need for new and strategically accessible sources of oil and gas. With the continually increasing demand for oil and gas, the requirement for pipeline steels with higher strength, toughness and weldability has been one of the most important factors driving the development of high strength pipeline steels, particularly with the oil exploration proceeding into arctic and deep sea regions, enhancing the weldability and mechanical properties of the new pipeline steels and weld consumables. Developments in the welding processes for manufacture and field welding are described in terms of process principles, equipment, consumables, weld quality, process economics and further developments. The increasing and changing requirement for weldability and mechanical properties in the heat affected zone and weld metal of pipeline welds are presented along with the reported solutions to the problems.

An investigation on girth friction welding of duplex stainless steel pipes

“…X70, X80, X100 and X120 are widely used for the transportation of oil and gas, and finding a suitable joining technique for such pipes has always been a challenging task. Liu and Bhole [1] presented a critical examination of the degradation of mechanical properties in the heat affected zone (HAZ) of fusion welded joints of high strength steel linepipes. The authors noted significant sofening of HAZ and deterioration of HAZ toughness and attributed the same to high heat inputs during submurged arc welding (SAW) of X100 and X120 steels.…”

“…The addition of both Ni and Mo powders respectively between 2.03%-2.91% (wt) and 0.70 %-0.995 % could improve the joint toughness due to substantial reduction in the detrimental phases such as grain boundary ferrite (GBF) and secondary phase ferrite (SPF) in weld metal microstructure. Liu and Bhole [1] reported further that the fusion welding processes such as gas metal arc welding (GMAW), gas tungsten arc welding (GTAW) and SAW of high strength steel linepipes could result in cold cracking of the welded joints. Linepipes of duplex stainless steel (DSS) are increasingly preferred for onshore piping applications due to their high strength, superior toughness and excellent corrosion resistance.…”

Experimental investigation of structural integrity behavior of High strength low alloy steel – Study of mechanical, microstructural and corrosion behavior of Submerged arc welding weldments

“…Further, the use of new material in different industries such as pipelines, bridges, structures and automobiles puts focus on a better understanding of qualifying requirements of welding for reducing the failures in future. 9 Appropriate weld joint is required to meet the specified strength of High strength low alloy steel as specified during manufacturing process. It was reported that combined electrode manual welding technique was used to solve this problem.…”

Hydrogen-Induced Cracking of Laser Beam and Gas Metal Arc Welds on API X65 Steel

“…Therefore, improving welding productivity is very important to reduce the cost of pipeline construction. The pipeline welds also require high strength, toughness, and resistance to sulfide stress corrosion cracking (SSCC) and hydrogeninduced cracking (HIC) to prevent leaks and protect the environment [1]. Normally, gas metal arc (GMA) welding is used in pipeline construction.…”