Girth weldability and welding process of Baosteel X80 UOE linepipes

An analysis of the girth weldability of Baosteel X80 UOE (U-ing-O-ing-Expanding) linepipes was conducted using manual shielded metal arc welding (SMAW) and semiautomatic self-shielded flux cored wire arc welding (FCAW).A technical specification for the optimum quality of a girth welding joint was obtained through a large amount of testing.According to the requirements of America Petroleum Institute(API) standard 1104 and the standards of the 2nd West-East natural gas transmission pipeline project,the mechanical properties of a girth welding joint were estimated.In addition,the effect of the girth welding procedure specifications and the consumable’s suitability on the impact toughness of the girth welding joint was discussed.