Analysis on the Corrosion of the Inner Cavity of the Christmas Tree Hydraulic Valve in a Well in Western China

In this paper, with the observing corrosion morphology of the inner cavity of the Christmas tree hydraulic valve and detecting the physical and chemical properties of the material (chemical composition, mechanical properties and metallographic structure),It is found that the main reason for the corrosion of the inner cavity of Yidong fan is that in the production process, due to improper heat treatment process, Cr element is accumulated in the metallographic structure of the hydraulic valve matrix, forming a grid like high Cr region, and the grid becomes a low Cr region, under the action of formation water containing CO2, the low Cr area is corroded, and large and deep corrosion pits are formed in the internal cavity of the hydraulic valve.