Steels for sour service: research in Escola Politécnica, University of São Paulo (EPUSP)

Microstructure-property relationships for metallic materials are basic requirements for the design of industrial processes to produce special materials, such as HSLA steels. Currently, there is a demand for materials resistant to aggressive environments having chloride, sulfide and carbon dioxide, all of which are corrosive and embrittling to steels. These environments are present in the extraction and transport of oil and natural gas from deep water. Escola Politécnica, University of ão Paulo, in its Department of Metallurgical and Materials Engineering, has ongoing research aiming at the development of HSLA steels resistant to corrosion, specifically stress corrosion cracking and susceptibility to hydrogen induced cracking under wet hydrogen sulfide and carbon dioxide environments. These objectives were the scope of a project,supported by CBMM (Companhia Brasileira de Metalurgia e Mineração), which contributed to the construction of a laboratory dedicated to the study of corrosion, embrittlement and stress-corrosion by hydrogen sulfide. Development of experimental methods for the measurement of corrosion resistance, evaluation of the effect of inclusions on corrosion behavior and comparison between API 5L X65 and X80 steels with regard to hydrogen embrittlement are some of the achievements from utilizing such a laboratory. Microstructures under study are the ones of as-rolled plates and of pipes; modified structures are produced in laboratory conditions in the Phase Transformations Laboratory and also in the Department of Metallurgical and Materials Engineering. This paper presents part of the history of the Electrochemical Processes Laboratory, where such corrosion studies are made and gives some important results for production of steels for deep water oil exploitation and future projects. (AU) © CBMM