Abstract:In order to study the erosion behavior of the solid particles in the drilling fluid on the valve surface of the managed pressure drilling throttle valve,the water jet method was conducted to simulate the working condition of throttle valve,and the erosion performances of 40Cr were explored under different impact angles.The relationship between erosion mass loss of 40Cr and impact angles were studied and the erosion shape of specimen was captured by 3D scanner under different impact angles.The erosion area of the specimen was observed by SEM to analyze the mechanism of erosion of the specimen under different impact angles.Experimental results show as impact angle increases from 15°to 90°,the depth of erosion pits and the erosion mass loss are increased first and then decreased,which achieve the maximum at 45°.Meanwhile,the erosion pits of specimens change from ellipse to circle gradually.With the increase of time,the erosion mass loss is increased in an exponential manner at 90°.The main erosion mechanisms are “plougheffect” at a low impact angle and “impact” at a high impact angle,however,the interaction of the two mechanisms reach the maximum at the impact angle of 45°.The result illustrates that,by changing the spool profiles to avoid the particle impact angle of 45°,the erosion wear of the throttle valve can be reduced.