Numerical Modeling and Experimental Investigation of M-4330 Low Alloy and 17–4 PH Stainless Steels Low Cycle Fatigue Behavior

Fatigue failure is the main concern in designing and manufacturing of different engineering equipment including fracture pumps. These pumps were basically designed for ordinary drilling applications. However, after invention of the hydraulic fracturing technology, they were also employed in unconventional drilling too. Longevity of the fracture pumps can significantly drop due to the unconventional drilling effects leading to the fatigue failure, particularly in the fluid end module. Therefore, to compensate the unconventional drilling detrimental impacts and increase the service life of the pumps, accompanying by considering new designs and manufacturing processes, new alloys have also been employed. Modified 4330 low alloy and 17–4 PH stainless steels are two relatively new ferrous alloys used for manufacturing the fluid end module of fracture pumps. In here, strain based fatigue experiments were performed to investigate the cyclic behavior and extract the low cycle fatigue properties of both alloys. A combined nonlinear kinematic/isotropic hardening model was developed by utilizing the experimental results and materials low cycle fatigue behaviors were numerically modeled through finite element analysis method. Finally, this study compares the numerical results derived from FEA model and common cyclic loading analytical equations to evaluate the accuracy of each approach.