The effect of cooling rate-induced microstructural changes on CO2 corrosion of low alloy steel
Kapil Kumar Gupta, Saber Haratian, Shivangi Gupta, O.V. Mishin, Rajan Ambat
Abstract
The effect of cooling rate-induced microstructural changes on corrosion resistance in a CO2-saturated 3.5 wt% NaCl solution have been explored for the API L80–1Cr steel. The corroded layer majorly contains siderite, akagenite, and undissolved cementite. The amount of FeCO3 in this layer is larger for the water-cooled sample with a martensitic structure, whereas the furnace-cooled sample with a ferritic-pearlitic structure contains a larger amount of akagenite. The retained cementite and the microrough surface of the furnace-cooled sample provide greater anchoring to the scale. Comparing samples cooled at different rates, the furnace-cooled condition appears to provide better CO2 corrosion resistance.