Analytical solution for the general mechanochemical corrosion of an ideal elastic–plastic thick-walled tube under pressure

The paper presents analytical solutions for the equal-rate mechanochemical wear of an ideal elastic–plastic thick-walled cylindrical tube subjected to any combination of internal and external pressure. The rates of corrosion at the inner and outer surfaces are supposed to be proportional to the equivalent tensile stress at the surface involved when it exceeds a given threshold. Furthermore, the corrosion rate can decay exponentially with time. The obtained solutions allow to assess the time of the initial yielding at the bore of the tube and the time of fully plastic yielding. Calculations showed that the time of plastic-zone propagation throughout the tube wall can be much greater than the length of the pure elastic stage. The proposed analytical solutions are to be used for design purposes and as benchmark solutions for numerical analysis.

• An analytical solution for the mechanochemical wear of a thick-walled tube is presented.
• Stresses in a tube grow due to corrosion and, in turn, increase corrosion rates.
• The times of the initial yielding and fully plastic yielding are determined.
• It is shown that the partially plastic stage can be an essential part of the total life of a tube.