摘要
【目的】传统热挤压三通制造工艺复杂,组织性能与质量水平不稳定,容易出现三通本体强度或韧性不满足标准要求等问题,严重制约油气管道的安全平稳运行,因此亟需对三通的性能提升与质量控制方法开展研究。【方法】通过对油气管道工程用X80钢级、直径1219 mm等径三通的结构进行优化设计与安全性评价,改善局部应力集中的问题。采用京雷焊丝与电弧增材技术实现了等径三通的增材制造,对产品开展微观组织、力学性能、缺陷与残余应力测试,并对等径增材三通及其环焊缝进行耐压试验与往复循环压力波动试验。【结果】在控制总质量的前提下,优化改进三通结构后,设计压力下三通所受最大应力降低了38 MPa,三通主管连接区域应力降低约50%。增材制造的X80三通力学性能稳定,各部位、方向心部与表面的性能及组织均匀,强度、韧性各向异性小,无厚度效应。相控阵超声与常规超声适用于增材制造三通的缺陷检测,整体热处理可显著降低增材制造三通生产过程中的残余应力。【结论】X80增材制造三通及其连接环焊缝性能远高于同钢级热挤压三通,整体可承受的最大压力超过57.5 MPa,焊接短节爆破裂纹扩展至增材三通管件肩部后停止,具有良好的韧性与止裂能力。增材制造技术提高了三通的安全性与稳定性,为低温服役环境等特殊场景适用的三通设计与制造提供了新的思路与方法。
[Objective]The traditional hot-extruded tees are manufactured through a complex process and exhibit unstable organizational properties and quality levels.These tees are susceptible to having strength or toughness levels below standard requirements,thereby significantly impeding the safe and stable operation of oil and gas pipelines.Hence,it is imperative to explore methods to enhance properties and ensure quality control for tees.[Methods]This study introduced equal tees made of X80 steel with a diameter of 1219 mm for the structural design optimization and safety evaluation of oil and gas pipelines,aimed at addressing local stress concentration issues.These equal tees were fabricated using Jinglei welding wires and the arc additive manufacturing(AM)technique.Various tests,including assessments of microstructures,mechanical properties,defects,and residual stresses,were conducted on the products.Additionally,pressure tests and reciprocating pressure fluctuation tests were performed on these equal tees and their circumferential welds.[Results]The tee structure was optimized and improved on the prerequisite of fulfilling the weight control requirement.The maximum stress in the tees under design pressures decreased by 38 MPa,while the stress at the tee connections to the main pipelines was reduced by approximately 50%.The mechanical properties of the X80 tees,produced through additive manufacturing,demonstrated stability,and their behaviors and microstructures were observed consistent across all parts and directions,including their cores and surfaces.Their strength and toughness exhibited minimal anisotropy and were unaffected by thickness variations.Both phased array ultrasonic testing and conventional ultrasonic testing proved effective for defect detection in AM tees.Additionally,bulk heat treatment was found to be highly beneficial in significantly reducing residual stresses during the production of AM tees.[Conclusion]The X80 AM tees and their circumferential welds for connection significantly outperform hot-ext
作者
田野
TIAN Ye(PipeChina West Pipeline Co.Ltd.)
出处
《油气储运》
CAS
北大核心
2024年第7期787-795,共9页
Oil & Gas Storage and Transportation
关键词
油气管道
高强度
三通
增材制造
X80钢
oil and gas pipeline
high strength
tee
additive manufacturing(AM)
X80 steel
