Material flow influence on the weld formation and mechanical performance in underwater friction taper plug welds for pipeline steel. (25th December 2015)

• Record Type: Journal Article
• Authors: Yin, Yayun; Yang, Xinqi; Cui, Lei; Wang, Feixiang; Li, Shengli
• Is Part Of: Materials & design. Volume 88(2015:Dec.)
• Page Start: 990
• Page End: 998
• Publication Date: 2015-12-25
• Subjects: Underwater welding -- Friction taper plug welding -- Material flow -- Mechanical properties -- Pipeline steel; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2015.09.123
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Friction taper plug welding experiment was conducted on X65 pipeline steel in underwater wet condition. Results indicate that the weld defects, microstructural evolution and mechanical properties are closely related to the material flow behavior during welding. The formation of weld defect characterized by incomplete filling or lack of bonding is mainly caused by the poor flowing property of the plug material especially in low axial welding force. In the experiment condition, rising the axial force would result in better material flow, higher weld power, more energy input and further improve the bond quality of the weld. Microstructure of both weld zone and heat-affected-zone mainly consists of lath bainite which results in an overmatching condition through the weld. High quality welds in this study also exhibit good tensile and impact properties that is equal to the base metal and acceptable bend property of 105° as the best. Graphical abstract: Highlights: Defect-free underwater FTP welds with favorable properties in pipeline steel were obtained. The shortcoming of material flow and heat input in HDP is a key factor for the formation of weld defects. Higher axial force is beneficial for omitting root defect and achieving high quality welds.