X70 grade large diameter line pipe with helical and longitudinal seam SAW was developed and used in West-East Pipeline Project of Petrochina. The operation pressure of the pipeline was designed as 10 MPa, with diamete...X70 grade large diameter line pipe with helical and longitudinal seam SAW was developed and used in West-East Pipeline Project of Petrochina. The operation pressure of the pipeline was designed as 10 MPa, with diameter of 1016 mm OD. This project represents the first high-pressure, large diameter and high strength grade gas pipeline in China. All the factors affecting the safety of the pipeline shall be considered. The welds quality of line pipe is very important for safety of the pipeline. Acicular ferrite type X70 grade pipeline steel was adopted for the base material. The welds performances of X70 line pipes with 1016mm OD and 14.6-21.0 mm WT has reached a very high level, especially of low temperature Charpy V impact toughness of welds metal. Welding technique and quality status of X70 line pipe of China are investigated in this paper.展开更多
利用Gleeble-3500热模拟试验机,测定了Φ406.4 mm×16.5 mm X70深海无缝管线钢管(/%:0.07C,0.70Si,0.80Mn,0.008P,0.002S,0.25Ni,0.25Cr,0.20Mo,0.10Cu,0.06V,0.03Nb,0.04Alt,0.0060N)的CCT曲线,并通过光学显微镜,扫描电子显微镜,H...利用Gleeble-3500热模拟试验机,测定了Φ406.4 mm×16.5 mm X70深海无缝管线钢管(/%:0.07C,0.70Si,0.80Mn,0.008P,0.002S,0.25Ni,0.25Cr,0.20Mo,0.10Cu,0.06V,0.03Nb,0.04Alt,0.0060N)的CCT曲线,并通过光学显微镜,扫描电子显微镜,HV硬度计分析了0.1~100℃/s的冷却速度下钢管的组织特征。结果表明,冷却速度为0.1~5℃/s时钢中组织主要为铁素体+珠光体,当冷却速度大于5℃/s时,钢中组织为贝氏体+铁素体;随冷却速度的提高,钢组织细化,硬度增加;当冷却速度为30~50℃/s时,可以获得适量的板条贝氏体组织,从而可保证管线钢有良好的力学性能。展开更多
文摘X70 grade large diameter line pipe with helical and longitudinal seam SAW was developed and used in West-East Pipeline Project of Petrochina. The operation pressure of the pipeline was designed as 10 MPa, with diameter of 1016 mm OD. This project represents the first high-pressure, large diameter and high strength grade gas pipeline in China. All the factors affecting the safety of the pipeline shall be considered. The welds quality of line pipe is very important for safety of the pipeline. Acicular ferrite type X70 grade pipeline steel was adopted for the base material. The welds performances of X70 line pipes with 1016mm OD and 14.6-21.0 mm WT has reached a very high level, especially of low temperature Charpy V impact toughness of welds metal. Welding technique and quality status of X70 line pipe of China are investigated in this paper.
文摘利用Gleeble-3500热模拟试验机,测定了Φ406.4 mm×16.5 mm X70深海无缝管线钢管(/%:0.07C,0.70Si,0.80Mn,0.008P,0.002S,0.25Ni,0.25Cr,0.20Mo,0.10Cu,0.06V,0.03Nb,0.04Alt,0.0060N)的CCT曲线,并通过光学显微镜,扫描电子显微镜,HV硬度计分析了0.1~100℃/s的冷却速度下钢管的组织特征。结果表明,冷却速度为0.1~5℃/s时钢中组织主要为铁素体+珠光体,当冷却速度大于5℃/s时,钢中组织为贝氏体+铁素体;随冷却速度的提高,钢组织细化,硬度增加;当冷却速度为30~50℃/s时,可以获得适量的板条贝氏体组织,从而可保证管线钢有良好的力学性能。
