基于DNVGL标准全自动超声波(AUT)检测系统认证

AUT检测技术具有高效、环保等优点,已成为海底管线铺设过程中优选的检验方法,得到了广泛应用。DNVGL标准要求,AUT检测系统需通过认证,验证AUT检测系统的检测和缺陷定量能力。本文介绍了AUT检测系统认证过程中的缺陷制作、重复性试验、温度灵敏度试验和可靠性试验的方法及要点,分析了AUT检测系统认证的影响因素,获得的试验结果满足标准要求,确保了AUT检测系统在海管铺设过程中可靠实施。     

耐腐蚀合金复合材料海底管道环焊缝各区域全自动超声波检测

CRA(耐腐蚀合金)复合材料海底管道内表面通常堆焊约3mm厚的625不锈钢,该海底管道环焊缝通常采用射线(RT)检测技术评估焊缝的焊接质量。由于RT检测效率较低,安全风险较高,极大地影响了CRA复合材料海底管道铺设效率。针对以上问题,对全自动超声波(AUT)检测工艺进行研究,主要通过综合运用低频纵波相控阵(PA)探头,爬波探头、双晶纵波相控阵(TRL)探头以及超声衍射时差(TOFD)探头,对制作的22个人工缺陷焊缝(共242个不同区域的人工缺陷)进行评价试验,并与RT检测评价结论进行对比分析,以评估该AUT检测工艺对CRA复合材料海底管道环焊缝各个区域缺陷的检出率。     

海底管线AUT分区法缺陷高度定量测量修正方法

针对海底管线AUT分区法缺陷高度定量测量存在较大误差的情况,分析了分区法高度定量误差产生的原因,通过理论分析提出高度定量测量修正方法,通过试验对比分析,证明了高度定量修正方法的正确性及可靠性[1-4],并得到第三方机构的认可。对于根部,表面及内部缺陷,通过此方法修正后,可使AUT分区法定量测量精度提高到1mm以内,充分发挥了海底管线不同位置缺陷不同评定方法的优势,为今后海底管线铺设提供更好的质量保障。     

ECA评估在海底管道AUT检测中的应用

AUT检测技术在海底管道的检测方面具有检测速度快、对面积性缺陷检出率高、缺陷定位准确和显示直观等优势,具有广泛的应用前景。现有海底管道标准中给出缺陷验收尺寸不能满足AUT系统的要求。本文根据DNV-OS-F101标准中的建议,采用工程临界评估(Engineering Critical Assessment-ECA)技术建立一套二维尺寸的缺陷验收标准,用于海底管道AUT检验。     

基于DNV GL标准的全自动超声波检测项目验证方法

耐腐蚀合金复合材料(CRA)海底管道主要应用于高酸性油气介质的输送。规格通常是管径为168.3508mm,壁厚为14.131.6mm,耐腐蚀合金层厚度为3mm。根据标准DNV-OSF101(2013)《海底管线系统》要求,全自动超声波检测(AUT)工艺需要经过验证,确保AUT与宏观切片评定的缺陷高度差值小于1mm。由于CRA复合材料海底管道规格各异,AUT检测工艺也需要进行相应的调整。文章基于管径为508mm、壁厚为31.6mm(CRA厚度为3mm)的管道进行了项目验证,通过AUT试块校准、人工缺陷焊缝制作、缺陷焊缝扫查、宏观切片和数据分析,最终评定出AUT检测工艺的缺陷检出能力和缺陷高度定量精度。有望在耐腐蚀合金复合材料(CRA)海底管道环焊缝检测工作中得到应用。     

钢悬链线立管焊缝的自动超声检测

在对钢悬链线立管(SCR)焊缝进行自动超声检测(AUT)的过程中,要求AUT具有可靠的检测能力和较高的检测精度。通过修正AUT缺陷评定方法,验证了AUT焊缝缺陷评定结果与金相检验结果的可靠性。结果表明,修正后的AUT评定结果与缺陷实际尺寸具有良好的一致性,为基于工程临界分析(ECA)验收标准的SCR管线的安装工程应用提供了借鉴。     

海底管道环焊缝的相控阵超声检测

子母型海底管道通常以主管线输送海洋油气,子管线输送化学物质的方式进行管道运输。母管规格(外径)通常为6~12inch(15.2428.48cm),子管规格(外径)通常为2inch(5.08cm)。母管环焊缝通常采用全自动超声检测技术(AUT)进行检测,而2inch子管由于设备工装限制,AUT技术无法应用。若采用射线检测技术(RT),不仅检测效率低,安全风险高,还极大地影响了子母管的铺设效率。针对以上问题,对相控阵超声检测(PAUT)技术进行研究,设计开发了满足2inch子管环焊缝检测的PAUT工艺,并对制作的35个管径为2inch,壁厚为6.4mm海管的人工缺陷焊缝(共105个人工缺陷)进行检测和缺陷高度定量精度评价,以评估该PAUT检测工艺对2inch子管环焊缝各区域缺陷的检出能力和高度定量精度。     

海底管线环焊缝的双丝焊接及无损检测

介绍了双丝焊接技术和自动超声波检测技术在海底管线环焊缝焊接施工中的应用。指出。双丝焊接不仅可以提高焊接效率和焊接质量，而且有利于改善焊接接头的拉伸性能和断裂韧性；自动超声波检测技术具有检测效率高和成本低的特点，满足了海底管线铺设时效性要求和焊缝质量控制要求。     

海底石油管线的相控阵检测技术应用

本文着重将手工相控阵检测技术引入到海底石油管线检测的应用中去,针对海管特定的壁厚和坡口形式提出了全新的相控阵(PAUT)检测参数设置,并在ESBTOOL模拟仿真软件中进行了声束模拟,确保焊缝两侧的相控阵探头发出的超声波能够覆盖整道焊缝。全自动超声波技术(AUT)已是世界上一项成熟的检验技术,而AUT校准试块是AUT检验正确的重要保障。为了进一步验证海管检测对于海上温度和湿度变化的可靠性,特在海上应用PAUT技术对AUT校准试块上人工缺陷进行检验实验。结果表明,PAUT技术检出率为100%,测长定量准确率高,能够成功运用于海管铺设的检测中。     

近海油气管线铺设的高效焊接技术研究

焊接施工是海底管线铺设过程中的重要环节,制约着铺管质量及效率.从S型铺设和J型铺设两大类方法出发,分别介绍了熔化极气体保护焊、闪光对接焊、高能束焊、单极脉冲焊以及激光复合焊等焊接技术,并介绍了深水管线铺设中适用于钛合金立管的焊接技术.通过分析影响海底管线铺设的焊接因素和一些发达国家的工程化应用研究历程,提出了基于光纤激光器的复合焊接技术是未来高效海底管线铺设连接的发展方向之一.     

Experimental and numerical investigation on combined girth welding of API X80 pipeline steel

Abstract

API X80 pipeline steel is widely used in natural gas and oil transportation. In this study, X80 pipeline steels with 18.4?mm thickness and 1219?mm diameter, made in China, were welded by a combined girth welding technology. Experimental results showed that microstructures in weld metal and coarse grain heat affected zone are mainly composed of coarsening bainite grains with dimensions of 20–50?μm, and Vickers hardness in weld seam is lowered by the seven-pass welding process. Simulated results illustrated that repeatedly thermal cycles imposed by the combined multipass girth welding process easily result in softened weld joints. The predicted microstructures, phase compositions and hardness in weld metal are in agreement with the measured ones. The results could be applied to optimise this combined girth welding process and improve the weld quality of API X80 pipeline steel and even higher grade pipeline steels.     

环焊接头强度对高应变海洋管道轴向承载能力的影响

基于应变设计的油气输送管道,环焊接头的强度对管道轴向变形能力起着至关重要的作用。以OD559×31.8 mm L485高应变海洋管道环缝为研究对象,采用有限元方法和数字图像相关法(DIC)拉伸试验及宽板拉伸试验,研究了GMAW环焊接头不同区域的强度变化对管道轴向承载能力的影响。结果表明,随焊缝金属强度的升高,管道轴向极限载荷和轴向平均应变增大,失效位置由焊缝向热影响区和母材转移;根焊金属占比小,热影响区很窄,高强匹配时根焊金属和热影响区强度对管道轴向极限载荷和轴向平均应变影响较小;在轴向载荷下,低强匹配环焊接头的母材、热影响区和焊缝的轴向应力和轴向应变分布极不均匀。受母材的拘束作用和焊缝金属自身的形变强化,低强匹配焊接接头的抗拉强度高于全焊缝金属,但变形和屈服主要集中在焊缝区域,容易导致管道环焊缝断裂失效。     

基于红外热成像技术的管道激光/电弧复合焊质量在线监测系统

利用福禄克RAYPi20HTRC红外热像仪,获取焊接熔池的红外热成像图像,通过软件对焊接熔池热成像图像进行处理,依据焊接熔池温度梯度分布对当前时刻焊接成型和焊接质量进行判断,识别和判断焊接缺陷,利用算法和程序对焊接质量进行评估,并记录当前的焊接时间和焊接点位,生成焊接记录。系统经过油气管道激光/电弧复合焊接应用试验具有运行稳定、质量评价与缺陷判定准确的特点,可以为现场焊接质量监测和后续焊接质量检测提供重要参考,具有重要工程应用意义。     

海底管道自动超声检测带状图的测长精度及修正

针对海底管道对接环焊缝全自动超声检测(AUT)中,分区法带状图测量缺陷长度存在误差的情况,使用不同方法对试块中已知尺寸的人工反射体进行测量,并与已知尺寸进行比较,计算误差值。通过数据分析,证明了采用试块误差值修正后的缺陷长度更加精确。该方法对接近标准允许的临界尺寸缺陷的评定起到了积极作用,可在一定程度上减小因缺陷长度评定造成的误判和漏判,提高了施工效率。     

An experimental study of the fracture properties of oil pipeline girth welds

The application of fracture mechanics to the "Fitness For Purpose" assessment of the fracture properties of pipeline girth welds is generally essential for the safe operation of oil pipeline systems. Based on the analysis of the fracture toughness requirements of the oil pipeline girth weld, a systematic study has been conducted on the fracture behavior of the API 5L X65 steel pipelin egirth weld made by two welding materials. The critical COD values of the pipe line girth weld under the different temperatures are tested. In the paper other influential factors on fracture behavior are also discussed, such as the welding materials, the welding positions (flat welding, vertical welding, overhead welding), the welded joint area (weld, heat-affected zone, fusion line and base metal) and the experiment temperature. The result shows that the welding material, the welded joint area and the experiment temperature have considerable influence on the fracture behavior of pipeline girth welds. It is also concluded that t he effect of the welding position is related to the welding process. The study provides a scientific basis for the welding of oil pipelines.     

高钢级管道环焊缝裂纹失效分析

含裂纹缺陷的环焊缝失效分析,是解决X70及以上高钢级管道环焊缝质量风险的必要环节。文中对现阶段含裂纹缺陷的环焊缝排查和失效分析进行了梳理和成果总结分析,及时发现问题和规律,为后续安全管控和裂纹机理研究提供参考。已有失效分析规律总结如下：X70及X80管道环焊缝裂纹以根焊开裂形式为主;变壁厚、管道顶部和底部等位置容易发生环焊缝裂纹缺陷,焊接施工和缺陷无损检测及评判时应重点关注,尽量避免漏评误判;焊瘤、错边、余高等外观检测指标超标,导致环焊缝成形较差,影响裂纹缺陷的检出并加重根焊位置的应力集中。基于上述规律,建议对新建管道需加强针对管道环焊缝外观检测、根焊裂纹检测工艺。而对于在役管道,重点防范弯曲等附加载荷影响,依托环焊缝裂纹失效分析,进一步研究环焊缝裂纹形成的微观机理和控制参数。     

Microstructures and properties of laser/arc hybrid welds and autogenous laser welds in pipeline steels

Abstract

Lasers are capable of producing welds with deep penetration, low distortion and faster travel speeds, compared to arc welding. More recently, laser/arc hybrid welding processes have also been generating interest for industrial fabrication. In this paper, six carbon–manganese, mainly pipeline, steels were welded using both autogenous Nd:YAG laser welding, and Nd:YAG laser/MAG hybrid welding. The improvements in weld microstructures and weld metal toughness that are possible when using the hybrid process are described and illustrated. Laser/arc hybrid welding is shown to be a process that can generate good quality welds in commercially available pipeline steels. It also has the potential to complete girth welds in these steels with significantly fewer welding passes than are currently required for arc welded pipelines, reducing the joint completion time.     

Numerical simulation and experimental verification of the restraint intensity of pipeline girth welding joint

The restraint intensity (RI) of the pipeline girth welding joint was investigated using finite element method and experimental method to predict the cold cracking susceptibility of pipeline steel. The distribution of RI along the girth weld was investigated to study the influence of welding position on the RI. Subsequently, the effects of outer diameter (OD) and wall thickness of pipeline on the RI were studied with ABAQUS software. The results show that the RI is almost independent of welding position. The RI increased with the increasing wall thickness but decreased with the increasing OD. A prediction model of RI was developed based on the effects of the OD and the wall thickness. It has been found that the predicted RIs were in good agreement with the experimental values. The maximum fractional error between the predicted RI and the experimental values was just about 10%. It was indicated that the errors were mainly caused by the heterogeneous of the weld bead.     

X60/625镍基合金复合管环缝焊接工艺及应用

X60/625双金属复合管环缝焊接时,由于2种材料化学成分和物理性能差异太大,易引起镍基合金层氧化、稀释等问题,从而影响覆层耐腐蚀性和管道完整性.针对该问题,文中通过对X60/625双金属复合管焊接性的分析和焊接工艺的研究,制定出适用于X60/625双金属复合管环缝焊接工艺.经过焊缝无损检验、理化性能检验、耐腐蚀性能检...