MODIFICATION OF EROSION CORROSION TEST APPARATUS AND STUDY OF THE EFFECT OF CO2 GAS PRESSURE ON EROSION CORROSION RATE OF API 5L X60 AND 5CT L80 STEEL PIPE MATERIALS IN CH3COOH ENVIRONMENT

• Main Author: Bambang Asmoro Aji, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/38535
• Institution: Institut Teknologi Bandung

The problem of corrosion of steel pipes in the oil and gas industry has caused losses to the industry. Steel pipes can corrode because they are in a corrosive environment. An example of corrosive substance contained in crude oil is CH3COOH. The presence of CO2 also affects corrosion. Pipe corrosion can be exacerbated by erosion that occurs in dynamic fluid environments. The study of the effect of CO2 pressure on the erosion corrosion rate of two types of API steel material is carried out in an acetic acid environment. Testing for erosion corrosion is carried out with an autoclave device that is personally designed. The specimens used are API 5L X60 steel (line pipe application) and 5CT L80 (tubing application) API 5L X60 and 5CT L80 steel specimens were characterized by OES and metallography, tested for mechanical properties by tension test and hardness test, tested for their corrosion properties by immersion test, polarization, and erosion. An autoclave that was originally used for CO2 gas pressurized immersion corrosion testing was modified to be an autoclave for CO2 gas pressurized erosion corrosion testing. The results of OES characterization and mechanical properties test are in accordance with API standards. The test results showed that X60 specimens were superior in corrosion resistance while L80 was superior in mechanical strength (yield strength, tensile strength, hardness). Specimens that have been tested for erosion were observed with a stereo microscope. The result showed pitting corrosion with different degrees for each specimen. In general, more pits are observed in higher pressure conditions. For X60 and L80 in 5 bar pressure condition, mesa attack was observed observed. Additionally, for L80, it is observed that the contours of surface corrosion resemble the fluid flow line characteristic.