Corrosion Fatigue Behavior of 6000 HP Fracture Pump of the Valve Body Under Different Plunger Stroke Times and Acid Fracture Fluid Environment

Abstract

As a key equipment for oil and gas extraction, the fracture pump is prone to failure due to fatigue crack in the crossbore of valve body. First, under acid fracture fluid and different loading frequencies, the fatigue crack growth rate of 17-4PH stainless steel was obtained by test, and the test data were used the modified Paris law. Then it is applied to numerical simulations to research the fatigue crack growth behavior of the valve body. The results show that the higher the loading frequency in the fracture fluid, the lower the fatigue crack growth rate, which is consistent with the test results. The influence of the working pressure on the stress intensity factor of the crack front is greater than that of the plunger stroke times. The model accurately predicts the fatigue crack orientation and corrosion fatigue crack growth life of the valve body.