Fatigue Analysis of Threaded Components with Cd and Zn-Ni Anticorrosive Coatings

The influence of the electrodeposition cadmium and zinc-nickel stress concentration effect on fatigue behavior AISI 4140 steel threaded components were studied. Axial tests at room temperature with a ratio R = 0.1 performed using standard specimens without nut interface under base material, cadmium, zinc-nickel-coated conditions. Finite element analysis (FEA) was used, considering both elastic elastoplastic models, to quantify distribution strain for interface. numeric results correlated experimental data interface, allow oil & gas companies extrapolate different thread dimensions, since are not feasible be all interfaces. Scanning electron microscopy (SEM) used analyze fracture surfaces. factor had greater performance than Cd Zn-Ni coatings. life studs reduced by about 58% nut/stud compared nuts. FEA showed that stud/nut higher values cracks nucleated regions strain, absorbed energy, concentration. substitution coating regarding strength smooth components.