采用废钢+70%~80%铁水-100 t UHP EAF-双工位120 t LF-VD-连铸-轧制工艺流程生产石油管用钢API5L BNS。通过电弧炉全程泡沫渣操作,EBT出钢合金化,连铸全程保护浇注,大压缩比、无扭微张力轧制,获得钢的良好的低倍组织、夹杂物、表面质量...采用废钢+70%~80%铁水-100 t UHP EAF-双工位120 t LF-VD-连铸-轧制工艺流程生产石油管用钢API5L BNS。通过电弧炉全程泡沫渣操作,EBT出钢合金化,连铸全程保护浇注,大压缩比、无扭微张力轧制,获得钢的良好的低倍组织、夹杂物、表面质量,满足极为严格的微量元素的控制目标,各项指标均满足用户协议要求。展开更多
为了评估API RP 5C5 CALⅣ循环交变复合载荷对螺纹接头密封性能的影响,基于Abaqus软件按照API RP 5C5 CALⅣ的B系、C系、A系试验载荷对特殊螺纹接头进行了有限元仿真分析。结果表明,运用有限元法可实现API RP 5C5 CALⅣ级试验加载全过...为了评估API RP 5C5 CALⅣ循环交变复合载荷对螺纹接头密封性能的影响,基于Abaqus软件按照API RP 5C5 CALⅣ的B系、C系、A系试验载荷对特殊螺纹接头进行了有限元仿真分析。结果表明,运用有限元法可实现API RP 5C5 CALⅣ级试验加载全过程的仿真模拟,循环复合载荷试验对接头密封性能有一定影响,其中C系载荷循环对接头的密封能下降量影响最小,密封能倍数最高;A系载荷下的接头的密封能倍数达到最低,其中在“24和25”载荷点下密封能倍数最低,是该类型接头的潜在泄漏危险点,需要重点关注。建议油田客户对于已通过API RP 5C5 CALⅣ试验验证的特殊螺纹接头系列,针对其新增准入规格可以进行简化的API RP 5C5气密封试验,此举既能在一定程度上有效表征其气密封性能,同时节约油田和厂家双方的时间和经济成本。展开更多
为了更好评价油套管特殊螺纹接头的性能,分析了API RP 5C5:2017和ISO 13679:2002标准的差异,并基于API 5C5:2017标准,对某特殊螺纹接头进行了密封性能评价。结果表明:试样经过上卸扣试验均未发生粘扣现象,极限样台肩扭矩与上扣扭矩的比...为了更好评价油套管特殊螺纹接头的性能,分析了API RP 5C5:2017和ISO 13679:2002标准的差异,并基于API 5C5:2017标准,对某特殊螺纹接头进行了密封性能评价。结果表明:试样经过上卸扣试验均未发生粘扣现象,极限样台肩扭矩与上扣扭矩的比值为0.24~0.78;在整个复合加载试验过程中,1#~4#极限样未出现结构失效及泄漏现象,1#~5#极限样在试验过程中的保载点或失效点均超过标准要求的极限载荷,满足API RP 5C5:2017 CAL IV标准的要求。展开更多
The thermophysical properties of API 5L X80 steel were experimentally measured, in order to use these in computational models to determine the temperature field in welded joints. In this work, values of thermal expans...The thermophysical properties of API 5L X80 steel were experimentally measured, in order to use these in computational models to determine the temperature field in welded joints. In this work, values of thermal expansion coefficient, specific heat, thermal diffusivity and thermal conductivity were experimentally obtained as a function of temperature. The thermal expansion coefficient was determined at temperatures of 20°C to 1200°C in a dilatometer DIL 402 PC. The specific heat was determined on a differential scanning calorimeter at temperatures between 300°C and 1200°C. The diffusivity and thermal conductivity were determined in the temperature range 100°C to 800°C in a 457 LFA diffusivimeter using laser flash technique. The thermal expansion coefficient remained approximately with constant value of 8.5 × 10-6 K-1 and suffered two falls reaching values -25 × 10-6 K-1 and -50 × 10-6 K-1 in the stages of heating and cooling respectively. It was observed for this material, minimum and maximum values of specific heat equal to 0.571 J/gK and 1.084 J/gK at temperatures of 300°C and 720°C, respectively. The behavior of thermal diffusivity and thermal conductivity in the temperature range 100°C to 800°C tends to decrease with increasing temperature. Based on the measured properties, computational modeling of the temperature field can be numerically obtained with better accuracy.展开更多
High-grade(API 5L X80)and large-diameter(OD 1422 mm)line pipes are used in the Sino-Russian eastern route gas pipeline project for high pressure(12 MPa)transmission,and this can significantly increase the transmission...High-grade(API 5L X80)and large-diameter(OD 1422 mm)line pipes are used in the Sino-Russian eastern route gas pipeline project for high pressure(12 MPa)transmission,and this can significantly increase the transmission capacity and meet China's energy strategic demand.With the increase of steel grade,transmission pressure,pipe diameter and design coefficient,however,ductile crack of line pipes becomes the dominant crack mode,so it is necessary to focus on crack arrest and control study.In this paper,therefore,an intensive study was performed on the Battelle Two-Curve(BTC)method which is the major solution to the calculation of arrest toughness,as well as the crack resistance curve and decompression curve.Based on the study,the principle and application range of the BTC method were confirmed.In addition,a series of analysis were conducted on the issues which occurred when the BTC method was applied to high-strength,high-toughness line pipe steel,and the commonly used modified approaches to BTC calculation results were also provided.After the crack control scheme of the X80 large OD 1422 mm line pipes for the Russian Bovanenkovo-Ukhta was reviewed,the BTC calculation results were corrected on the basis of the design parameters of the Sino-Russian eastern routine gas pipeline project,the Charpy V-notched(CVN)impact energy which meets the project requirement was finally worked out to be 245 J.展开更多
Oil and gas line pipes are laid underground and run through different areas in the laying process,so they will be subjected to different degrees of corrosion and even crack,leading to enormous casualties and economic ...Oil and gas line pipes are laid underground and run through different areas in the laying process,so they will be subjected to different degrees of corrosion and even crack,leading to enormous casualties and economic losses.In order to guarantee the safe operation of line pipes,therefore,it is significant to investigate the electrochemical corrosion behaviors of pipe steel in a simulated soil environment.In this paper,the electrochemical corrosion behaviors of the base metals and welding materials of API 5L X90 steel longitudinally submerged arc welding pipes in near-neutral simulated soil solution(NS4)were studied by means of the electrochemical impedance spectroscopy(EIS)and the potentiodynamic polarization testing technology.It is shown that the typical characteristic of anodic dissolution is presented but with no passivation phenomenon when X90 linepipe steel is put in NS4 solution.The base material is thermodynamically more stable than the seam weld material.The base material and seam weld samples were polarized under -850 mV polarization potential for different durations.It is demonstrated that with the proceeding of polarization,the polarization resistance and the corrosion resistance increase while the corrosion current density decreases.And the corrosion resistance of base material is better than that of seam weld material.展开更多
文摘采用废钢+70%~80%铁水-100 t UHP EAF-双工位120 t LF-VD-连铸-轧制工艺流程生产石油管用钢API5L BNS。通过电弧炉全程泡沫渣操作,EBT出钢合金化,连铸全程保护浇注,大压缩比、无扭微张力轧制,获得钢的良好的低倍组织、夹杂物、表面质量,满足极为严格的微量元素的控制目标,各项指标均满足用户协议要求。
文摘为了评估API RP 5C5 CALⅣ循环交变复合载荷对螺纹接头密封性能的影响,基于Abaqus软件按照API RP 5C5 CALⅣ的B系、C系、A系试验载荷对特殊螺纹接头进行了有限元仿真分析。结果表明,运用有限元法可实现API RP 5C5 CALⅣ级试验加载全过程的仿真模拟,循环复合载荷试验对接头密封性能有一定影响,其中C系载荷循环对接头的密封能下降量影响最小,密封能倍数最高;A系载荷下的接头的密封能倍数达到最低,其中在“24和25”载荷点下密封能倍数最低,是该类型接头的潜在泄漏危险点,需要重点关注。建议油田客户对于已通过API RP 5C5 CALⅣ试验验证的特殊螺纹接头系列,针对其新增准入规格可以进行简化的API RP 5C5气密封试验,此举既能在一定程度上有效表征其气密封性能,同时节约油田和厂家双方的时间和经济成本。
文摘为了更好评价油套管特殊螺纹接头的性能,分析了API RP 5C5:2017和ISO 13679:2002标准的差异,并基于API 5C5:2017标准,对某特殊螺纹接头进行了密封性能评价。结果表明:试样经过上卸扣试验均未发生粘扣现象,极限样台肩扭矩与上扣扭矩的比值为0.24~0.78;在整个复合加载试验过程中,1#~4#极限样未出现结构失效及泄漏现象,1#~5#极限样在试验过程中的保载点或失效点均超过标准要求的极限载荷,满足API RP 5C5:2017 CAL IV标准的要求。
文摘The thermophysical properties of API 5L X80 steel were experimentally measured, in order to use these in computational models to determine the temperature field in welded joints. In this work, values of thermal expansion coefficient, specific heat, thermal diffusivity and thermal conductivity were experimentally obtained as a function of temperature. The thermal expansion coefficient was determined at temperatures of 20°C to 1200°C in a dilatometer DIL 402 PC. The specific heat was determined on a differential scanning calorimeter at temperatures between 300°C and 1200°C. The diffusivity and thermal conductivity were determined in the temperature range 100°C to 800°C in a 457 LFA diffusivimeter using laser flash technique. The thermal expansion coefficient remained approximately with constant value of 8.5 × 10-6 K-1 and suffered two falls reaching values -25 × 10-6 K-1 and -50 × 10-6 K-1 in the stages of heating and cooling respectively. It was observed for this material, minimum and maximum values of specific heat equal to 0.571 J/gK and 1.084 J/gK at temperatures of 300°C and 720°C, respectively. The behavior of thermal diffusivity and thermal conductivity in the temperature range 100°C to 800°C tends to decrease with increasing temperature. Based on the measured properties, computational modeling of the temperature field can be numerically obtained with better accuracy.
文摘High-grade(API 5L X80)and large-diameter(OD 1422 mm)line pipes are used in the Sino-Russian eastern route gas pipeline project for high pressure(12 MPa)transmission,and this can significantly increase the transmission capacity and meet China's energy strategic demand.With the increase of steel grade,transmission pressure,pipe diameter and design coefficient,however,ductile crack of line pipes becomes the dominant crack mode,so it is necessary to focus on crack arrest and control study.In this paper,therefore,an intensive study was performed on the Battelle Two-Curve(BTC)method which is the major solution to the calculation of arrest toughness,as well as the crack resistance curve and decompression curve.Based on the study,the principle and application range of the BTC method were confirmed.In addition,a series of analysis were conducted on the issues which occurred when the BTC method was applied to high-strength,high-toughness line pipe steel,and the commonly used modified approaches to BTC calculation results were also provided.After the crack control scheme of the X80 large OD 1422 mm line pipes for the Russian Bovanenkovo-Ukhta was reviewed,the BTC calculation results were corrected on the basis of the design parameters of the Sino-Russian eastern routine gas pipeline project,the Charpy V-notched(CVN)impact energy which meets the project requirement was finally worked out to be 245 J.
基金Project supported by the CNPC Application Fundamentals Research Project,“Basic Research on Safe Operation of In-Service High-Strength Pipelines”(Grant No.2014B-3313).
文摘Oil and gas line pipes are laid underground and run through different areas in the laying process,so they will be subjected to different degrees of corrosion and even crack,leading to enormous casualties and economic losses.In order to guarantee the safe operation of line pipes,therefore,it is significant to investigate the electrochemical corrosion behaviors of pipe steel in a simulated soil environment.In this paper,the electrochemical corrosion behaviors of the base metals and welding materials of API 5L X90 steel longitudinally submerged arc welding pipes in near-neutral simulated soil solution(NS4)were studied by means of the electrochemical impedance spectroscopy(EIS)and the potentiodynamic polarization testing technology.It is shown that the typical characteristic of anodic dissolution is presented but with no passivation phenomenon when X90 linepipe steel is put in NS4 solution.The base material is thermodynamically more stable than the seam weld material.The base material and seam weld samples were polarized under -850 mV polarization potential for different durations.It is demonstrated that with the proceeding of polarization,the polarization resistance and the corrosion resistance increase while the corrosion current density decreases.And the corrosion resistance of base material is better than that of seam weld material.
