Calcium nitrate (Ca(NO₃)₂) has been suggested to inhibit steel corrosion. However, the effectiveness of corrosion inhibition offered by calcium nitrate in highly halide-enriched environments, for example, completion fluids, is not well known. To better understand this, the inhibition of corrosion of API P110 steel by Ca(NO₃)₂ was studied using vertical scanning interferometry in solutions consisting of 10 mass % calcium chloride (CaCl₂) or 10 mass % calcium bromide (CaBr₂), for example, to simulate the contact of completion fluids with the steel sheath in downhole (oil and gas) applications. The evolution of the surface topography resulting from the initiation and growth of corrosion pits, and general corrosion was examined from the nano-scale to micron-scale using vertical scanning interferometry. Special focus was paid to quantify surface evolution in the presence of Ca(NO₃)₂. The results indicate that, at low concentrations (≈1 mass %), Ca(NO₃)₂ successfully inhibited steel corrosion in the presence of both CaCl₂ and CaBr₂. Statistical analysis of surface topography data reveals that such inhibition results from suppression of corrosion at fast corroding pitting sites. However, at higher concentrations, calcium nitrate’s effectiveness as a corrosion inhibitor is far less substantial. These results provide a means to rationalize surface topography evolution against the electrochemical origin of corrosion inhibition by NO₃⁻ species, and provide guidance regarding the kinetics, and susceptibility to degradation of the steel sheath during exposure to halide-enriched completion fluids.

已建议硝酸钙（Ca（NO ₃）₂）抑制钢的腐蚀。但是，由硝酸钙在高度卤化物丰富的环境（例如完井液）中提供的缓蚀效果尚未广为人知。为了更好地理解这一点，在包含10质量％氯化钙（CaCl ₂）或10质量％溴化钙（CaBr ₂）的溶液中使用垂直扫描干涉法研究了Ca（NO ₃）₂对API P110钢的腐蚀抑制作用。），例如，模拟井下（石油和天然气）应用中完井液与钢套的接触。使用垂直扫描干涉法检查了腐蚀坑的产生和生长以及一般腐蚀引起的表面形貌的演变，从纳米级到微米级。特别关注在存在Ca（NO ₃）₂的情况下量化表面演化。结果表明，在低浓度（≈1质量％）下，Ca（NO ₃）₂在存在CaCl ₂和CaBr ₂的情况下都能成功地抑制钢的腐蚀。表面形貌数据的统计分析表明，这种抑制作用是由于抑制了快速腐蚀点蚀点处的腐蚀而导致的。然而，在较高的浓度下，硝酸钙作为腐蚀抑制剂的有效性远不那么重要。这些结果提供给针对由NO缓蚀的电化学原点合理化表面形貌演化的装置₃ ^-种，和暴露于卤化物富集完井液期间提供关于动力学指导，易感性钢制外皮的降解。