Research on the corrosion behavior of three typical alloy steels in LNG receiving station equipment

Abstract LNG receiving stations are deeply troubled by corrosion. Hence, it has increased the operational risks of the equipment. This paper selects three commonly used alloy steels in the equipment of the LNG as the research objects, and the evolution characteristics of the corrosion behavior of the alloy in the corrosive environment were systematically investigated by using the laboratory seawater simulation method and the on-site hanging plate test. The results show that Q235B and X60 exhibit similar corrosion behavior characteristics under the conditions of salt spray and full immersion accelerated corrosion tests. At the initial stage of corrosion, the corrosion rate is relatively high, and as the duration of the experiment increases, the corrosion rate decreases and stabilizes. 304L shows an extremely low corrosion rate. No obvious corrosion marks were found in the morphologies. Under the field test conditions, the corrosion rate of Q235B and X60 in the dock area was close. The corrosion rate decreased first and then increased with the field test time. The corrosion rate of 304L in the two areas was much lower than that of Q235B and X60, and there was almost no corrosion.