Abstract:
The corrosion behavior of high-strength and toughness 15 Cr stainless steel under H
2S and CO
2 production conditions was studied by sulfide stress cracking(SSC), stress corrosion cracking(SCC) tests, high temperature and high pressure corrosion simulation tests and in-situ electrochemical tests. The results show that under NACE TM0177 standard conditions(B solution) and simulated working conditions(90 ℃, 3 MPa CO
2, 2 kPa H
2S), the SSC and SCC sensitivity of high-strength and toughness 15 Cr stainless steel are low, showing excellent resistance to hydrogen sulfide stress corrosion cracking. Under the conditions of ultra-high temperature, ultra-high CO
2 and low H
2S partial pressure, the high strength and toughness 15 Cr exhibits good resistance to uniform corrosion and local corrosion. Compared with the partial pressure of CO
2 and H
2S, the influence of temperature on the corrosion rate is more significant, and its applicable temperature can reach 220 ℃(with a uniform corrosion rate of 0.09 mm/a and no obvious pitting corrosion). Under simulated conditions, p-n bipolar passivation film is formed on the surface of high-strength and toughness 15 Cr. Compared with Super 13 Cr, it has lower doping concentration(
NA=7.95×10
22cm
-3,
ND=1.87×10
22cm
-3), higher pitting protection potential(
Ep=-148 mV), and polarization resistance(
Rp=6048.69 Ω ·cm
2), and higher corrosion resistance. The research results provide a theoretical basis for the use of high strength and toughness 15Cr stainless steel in H
2S and CO
2 environment.