Three-point bend testing method was employed in the crack tip opening displacement(CTOD)test to investigate the fracture toughness of base metal
heat affected zone(HAZ)
and weld of an X100 longitudinal submerged arc welded(LSAW)pipe. The results show that at the same temperature
the δ
0.05
δ
i
and δ
m
in the X100 LSAW pipe distribute as: base metal>weld bead>HAZ; and the crack propagation resistance and tear modulus distribute as: base metal>HAZ>weld bead. Further analysis shows that the toughness of HAZ of X100 LSAW pipe closely relates with its microstructure. Large amount of polygonal ferrite in HAZ microstructure and less content of reinforcement phases
such as granular bainite
can lead to the decrease in fracture toughness
especially at low temperature
and the emergence of local instability.
关键词
Keywords
references
HILLENBRAND H G. Development of linepipe in grade up to X100 [C]∥ Proceedings of the 11th EPRG/PRCI Biennial Joint Technical Meeting on Pipeline Research. Arlington, MA, USA:Pipeline Research Council International, 1997: 6-10.
HILLENBRAND H G, KALWA C. High strength line pipe for project cost reduction [J]. World Pipelines, 2002, 2(1): 1-10.
GLOVER A. Application of grade 555(X80)and 690(X100)in Arctic climates [C]∥ Proceedings of Application Evaluation of High Grade Linepipe in Hostile Environments Conf. Yokohama, Japan: Scientific Surveys Ltd., 2002: 33-52.
BARSANTI L. From X80 to X100: know-how reached by ENI Group on high strength steel [C]∥ Proceedings of Application Evaluation of High Grade Linepipe in Hostile Environments Conf. Yokohama, Japan: Scientific Surveys Ltd., 2002: 231-244.
FAIRCHILD D P. High strength steels: beyond X80 [C]∥ Proceedings of Application Evaluation of High Grade Linepipe in Hostile Environments Conf. Yokohama, Japan: Scientific Surveys Ltd., 2002: 307-321.
BARSANTI L, HILLENBRAND H G, MANNUCCI G, et al. Possible use of new materials for high pressure linepipe construction: an opening on X100 grade steel [C]∥ Proceedings of 4th International Pipeline Conference. New York, USA: ASME, 2002: 287-298.
DEMOFONTI G, MANNUCCI G, HILLENBRAND H G, et al. Evaluation of the suitability of X100 steel pipes for high pressure gas transportation pipelines by full scale tests [C]∥ Proceedings of 5th International Pipeline Conference. New York, USA: ASME, 2004: 1685-1692.
高惠临.管线钢组织、性能与焊接行为[M].西安:陕西科学技术出版社, 1995: 157.
ASTM-E1290-2007 Standard test method for crack-tip opening displacement(CTOD)fracture toughness measurement [S]. Philadelphia, USA: American Society for Testing and Materials, 2007.
LIU Shouxian, LUO Haiwen, WANG Ruizhen, et al. Investigation on the phase transition and microstructure of X100 linepipe steel after continuous cooling [J]. Research on Iron and Steel, 2008, 36(1): 30-32.