海洋用X65MO钢级直缝埋弧焊管焊接接头强韧性研究OA

Addresses the special requirements for the longitudinal tensile properties of the weld seam and the impact toughness of the welded joint of the X65MO SAWL pipe as made by a certain project,the feasibility and rationality of the manufacturing process for the said pipe are experimentally analyzed.Based on the study of the regularity associated with the influence by different wire matches on the longitudinal tensile properties of the pipe's weld seam,it is revealed that when the longitudinal yield strength of the weld seam is reduced to the level of that of the base metal,it will probably cause cracking of the welded joint during the guided bending process,which would negatively affect the comprehensive mechanical properties of the steel pipe.Accordingly the embrittlement problem of the weld seam and heat-affected zone(HAZ)at the center of the wall of the Φ711 mm×19.1 mm X65MO SAWL pipe for marine service is solved by means of taking such measures as proper base metal chemical composition design,limitation of the impurity elements in welding materials,proper control of flux alkalinity,and optimization of the welding process,etc.As a result,the average Charpy impact energy values of the weld seam and the HAZ of the said pipe at 0℃reach 160 J and 279 J respectively,while the corresponding shear area ratios are up to 63%and 91%respectively.