Corrosion resistance of rolled and rerolled super martensitic steel in media containing chlorides and hydrogen sulfide

Abstract

In the oil and gas industry, super matensitic steels have been used primarily in the manufacture of seamless steel pipe for use in drilling oil and gas. The objective of this work is to evaluate the corrosion resistance of rolled and rerolled super martensitic steels in electrolytes of aqueous solution of NaCl 35 g/L, and aqueous solution of NaCl 120 g/L, sodium acetate 0.4 g/L, with pH 4.5 (standard solution), saturated and unsaturated with H 2 S, simulating the service conditions of petroleum industry in the pre-salt operation. For this evaluation, the electrochemical tests used are electrochemical impedance spectroscopy (EIS) and cyclic polarization test. The characterization techniques used are optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The effect of H 2 S saturation of the solutions studied on the corrosion resistance of steels was detrimental. The super martensitic steel in the rerolled condition showed a higher corrosion resistance than the rolled steel in an aqueous solution of 35 g/L NaCl and in a standard solution saturated with H 2 S. In the 35 g/L NaCl aqueous solution saturated with H 2 S and in the standard solution, the rolled steel showed a higher corrosion resistance than the rerolled steel. In an aqueous solution of 35 g/L NaCl, the rolled and rerolled steels showed pitting diameter of 140μm and 100μm, respectively.

Production of Seamless Steel Pipe for Oil and Gas Extraction in Challenging Conditions

“…The development of many new oil fields is complicated by the presence of carbon dioxide, which quickly corrodes carbon and low-alloy steel. This may be addressed by using high-chrome steel-for example, martensitic stainless steels with around 13% Cr [14][15][16][17]. To prevent CO 2 corrosion, the global production of such steel increased sharply in the 1980s.…”

Influence of Thermal Treatment on SCC and HE Susceptibility of Supermartensitic Stainless Steel 16Cr5NiMo

“…Supermartensitic stainless steels have been developed to offer increased corrosion resistance, especially in sour environments (containing hydrogen sulphide H 2 S) [1][2][3]. They also present remarkable weldability and fracture toughness even at low temperatures, in comparison with traditional martensitic stainless steels.…”