Per: Ihana Gabriela Conceição de Jesus (ufs), matheus duarte Macedo (ufs), isau de souza alves junior (ufs), Gustavo dória lima (ufs), Sandro Griza (ufs)
Abstract:
Oil, being so versatile, is widely used all over the world for many applications. For the extraction of petroleum, one of the most used techniques is to inject water into wells through a column of injection through valves. In these valves there are springs that are failing with undesired frequency. The springs thus become the object of study of this article so that one discovers the motive of the faults and then proposes viable and reliable solutions. In this way, metallographic, fractographic and hardness analyzes were performed. In view of this, it was verified that the spring in study presented preferential corrosion, besides the formation of pites that led to failure by overload. With the metallographic analysis, it was verified the microstructure formed by austenite grains. Thus, the spring was manufactured from wire that received high level of cold deformation, which reduces the resistance to corrosion, causing greater susceptibility. In this way, it is recommended to change the design of the drive or seal the spring against the electrolyte, or, selection of a drive principle that presents greater resistance against the corrosion of the medium.