深水钢悬链立管的开发

Development of deep-water steel catenary riser

宝钢开展了深水钢悬链立管有关材料和制造技术的国产化研究,利用460PQF轧管机组,成功试制了10 in和12 in(φ273.1 mm×25.4 mm和323.9 mm×27.0 mm)两个规格立管样管,综合力学性能和可焊性评价指标均较好地满足中海油的技术指标要求。采用低碳、低碳当量的钢种成分设计,宝钢试制的立管样管实现了全壁厚方向均匀一致的贝氏体组织,硬度分布均匀且HV10可控制在≤230的水平,同时具有良好的-30℃低温冲击韧性,其中A_(kv2)单值和均值均≥300 J,远远高于标准要求。另外,-30℃CTOD单值和均值在1.00 mm左右,显示材料具有良好的断裂韧性。采用全自动GMAW环焊工艺进行评价,焊接接头不同位置(焊缝、热影响区)具有良好的韧性,-30℃下的A_(kv2)值和-10℃下的CTOD值均满足相关技术标准的要求。在应力幅为300 MPa时,疲劳寿命≥10^(7)次,显示具有良好的抗拉压疲劳性能。且疲劳寿命数据显示,相同应力水平下,寿命分散性小,寿命稳定,显示宝钢立管材料的组织性能均匀一致。

Research on the material and manufacturing technology development of deep-water steel catenary riser was conducted in the Baosteel company.Trial production of riser seamless pipes with dimensions of273.1 mm×25.4 mm and323.9 mm×27.0 mm was successfully accomplished in the production line of 460 PQF continuous rolling mill.All the mechanical properties and weldability could satisfy the technical requirements given by the China National Offshore Oil Corporation well.Thanks to the chemical composition design with low carbon and low carbon equivalent for the steel,homogeneous tempered-bainite-type microstructure along the thickness direction was obtained and it guaranteed excellent mechanical properties behaviors,including the stable distribution of the hardness and good controlling of the hardness below 230(HV10),as well as the excellent impact toughness under-30℃,with the individual and average A_(kv2) values both surpass 300 J,which was far beyond the lower limit.High CTOD performance with both individual and average values around 1.00 mm was achieved,which revealed the high fracture toughness of the material.It was further proved that the weldability of the material was well enough to guarantee the A_(kv2) value at-30℃and CTOD value at-10℃met the corresponding standard by means of full-automatic GMAW process.Under the stress range of 300 MPa,long fatigue lifetime with cycles higher than 10^(7) times also certified that the riser material had good fatigue-resistant behavior when suffered cyclic alternating loads of tension and compression.Uniform microstructure and mechanical properties were further demonstrated by the narrow scatter of fatigue lifetime data values.