Dong Zhiqiang, Xu Zhenzhen, Wang Wenke, Bi Zongyue, Zhang Jianxun
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
Baoji Petroleum Steel Pipe Co., Ltd., Baoji 721008, China.
Materials (Basel). 2020 Aug 12;13(16):3561. doi: 10.3390/ma13163561.
Most oil and gas is transported by pipeline, and corrosion causes a great threat to the service life of the pipeline; bimetallic pipe, which combines the advantages of good mechanical properties, good corrosion resistance, and relatively low price, is a good choice for high-pressure and corrosion-resistant pipe, but its manufacturing process and stress distribution are more complex than single metal pipe. JCO is a widely used cold forming method for pipes which is named by the shape of the plate in the forming process, i.e. J-shape, C-shape and O-shape, and the forming process is an important parameter that determines the level of imperfections and residual stresses in a pipe, and residual tensile stress will accelerate corrosion failure of the pipe. In this study, the three-dimensional (3D) finite element method (FEM) is used to simulate the pre-bending and JCO forming process of a 2205/X65 bimetallic pipe. The model and the simulated results are validated by digital image correlation (DIC) experimental and the opening width of the formed pipe billet, respectively. The influence factors of the stresses are studied. Further, a two-dimensional (2D) model is established to study the characteristics of bimetallic plate bending and the stress distribution at the interface of different materials, and the results are compared with that of three-dimensional model.
大多数石油和天然气通过管道运输，腐蚀对管道的使用寿命构成巨大威胁；双金属管结合了机械性能良好、耐腐蚀性好和价格相对较低的优点，是高压耐腐蚀管道的理想选择，但其制造工艺和应力分布比单金属管更复杂。JCO是一种广泛应用于管材的冷成型方法，它以成型过程中板材的形状命名，即J形、C形和O形，成型工艺是决定管材缺陷程度和残余应力水平的重要参数，残余拉应力会加速管材的腐蚀失效。在本研究中，采用三维（3D）有限元方法（FEM）模拟2205/X65双金属管的预弯曲和JCO成型过程。分别通过数字图像相关（DIC）实验和成型管坯的开口宽度对模型和模拟结果进行了验证。研究了应力的影响因素。此外，建立了二维（2D）模型来研究双金属板弯曲特性和不同材料界面处的应力分布，并将结果与三维模型的结果进行了比较。
