Numerical Simulation and Experimental Confirmation of a Bimetallic Pipe Forming Process

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.

Effect of the Mould Rotational Speed on the Quality of Bimetallic Pipe Fabricated by Centrifugal Casting Process

Bimetallic pipes have found a wide range of applications in the present market scenario. It is due to the fact that they possess really impressive mechanical properties like high corrosion resistance at elevated temperatures, high strength, high toughness, etc. The bimetal pipes can be made by using several combinations of metals depending on the requirements like Al-Cu, Al-Ni, etc. Bimetallic pipes are manufactured by the principle of cladding where one metal is made to clad over another one. They have found their applications in steam condenser, heat exchangers, water supply, industrial applications, etc. These pipes are manufactured using the centrifugal casting process. This paper deals with the effect of the various mould rotational speeds on the quality of the bond produced in the Al-Cu bimetallic pipe while fabricating through the centrifugal casting process. The vertical centrifugal casting setup is used for the process. The detailed analysis of the bond quality is done using Scanning Electron Microscope (SEM). Furthermore, the chemical composition of the bond is studied by using Energy Dispersive X-Ray Spectroscopy (EDS). The strength and quality of the Al-Cu bimetallic bond is studied at varying rotational speeds of the mould and finally the observations are taken. The conclusion is framed accordingly based on the observations.