STUDY OF THE CORROSIVE PERFORMANCE OF HIGH MECHANICAL STRENGTH ALLOYS SUBMERGED UNDER LAKE MARACAIBO BRACKISH WATER

摘要

The following paper presents the corrosion performance of high-mechanical strength alloys immersed in Lake Maracaibo (Venezuela) brackish water at ambient temperature, these were: AISI 1018 Carbon steel, AISI 4140 low alloy steel, martensitic stainless steel type 416, precipitation hardened stainless steel type 17-4 PH, austenitic stainless steel types 304, 316 and XM-19, and the precipitation hardened Ni-Cu Alloy K-500. The alloys were metallurgically characterized through chemical, metallographic, and hardness analyses. Throughout the immersion of specimens in the water of the lake their tendencies to biofouling were qualitatively determined and the corrosion products were characterized. It identified the types of corrosion that affected them and it was quantitatively established the speed of attack. Conducting potentiodynamic polarization resistance and cyclic potentiodynamic polarization measurements, it was determined the electrochemical parameters that define the behavior of these alloys with respect to the corrosion by water of the Lake Maracaibo. The results of the following study allowed identifying the stainless steel types XM-19, 316, 304 and 17-4 PH as the alloys of high mechanical resistance recommended to be employed in immersion services in the water of the Maracaibo Lake at ambient temperature. There were established selection criteria for the best use of these alloys.