Authors

The demand of natural gas has been increasing. To meet the growing demand of natural gas, new gas fields must be developed. The transportation cost of gas to market is an important factor for the development of new gas fields, which are located in remote area. High-pressure gas pipelines by high strength steel pipes have been focused to find the solution of it. API grade X100 and X120 line pipes for high-pressure gas pipeline have been successfully developed and the application technologies have been studied to construct safe and economical pipelines. High quality steel and TMCP (Thermo-Mechanical Control Process) technology in plate rolling made it possible to achieve high strength and high toughness of X100 or X120 grade large diameter line pipes. Optimum steel chemistry for high strength and high toughness has been selected to maintain good weldability. Lower cooling finishing temperature has been applied to get higher strength. Pipes produced by UOE process were proved to meet X100 or X120 grade high strength line pipes for high-pressure operation. One of the key issues for the application of these high strength line pipes is the arrestability of propagating ductile fracture in high-pressure gas pipelines. A series of full scale burst tests were conducted to evaluate the arrest energy for high strength line pipes. It was reported that the prediction of arrest energ