The corrosion behaviors of X52, 3Cr low-alloy steel, and 13Cr stainless steel were investigated in an O_2–H2O–CO_2 environment at various temperatures and O_2–CO_2 partial-pressure ratios. The results showed that t...The corrosion behaviors of X52, 3Cr low-alloy steel, and 13Cr stainless steel were investigated in an O_2–H2O–CO_2 environment at various temperatures and O_2–CO_2 partial-pressure ratios. The results showed that the corrosion rates of X52, 3Cr, and 13Cr steels increased with increasing temperature. The corrosion rates slowly increased at temperatures less than 100°C and increased sharply when the temperature exceeded 100°C. In the absence of O_2, X52, 3Cr, and 13Cr exhibited uniform corrosion morphology and Fe CO3 was the main corrosion product. When O_2 was introduced into the system, various forms of Fe_2O_3 appeared on the surface of the samples. The Cr content strongly influenced the corrosion resistance. The 3Cr steel with a low Cr content was more sensitive to pitting than the X52 or 13Cr steel. Thus, pitting occurred on the surface of 3Cr when 1.25 MPa of O_2 was added; this phenomenon is related to the non-uniform distribution of Crin 3Cr.展开更多
Appropriate materials for injection pipelines and tubing for carbon dioxide geologic storage is fundamental to ensure asset integrity and save cost.This paper evaluates the corrosion behaviour of X65,1Cr,3Cr and 5Cr,w...Appropriate materials for injection pipelines and tubing for carbon dioxide geologic storage is fundamental to ensure asset integrity and save cost.This paper evaluates the corrosion behaviour of X65,1Cr,3Cr and 5Cr,which have the potential to be injection pipeline/tubing materials.The influence of steel Cr content on the general and localised corrosion behaviour was investigated at time periods from 6 to 192 h at 60℃and 100 bar.The evolution,morphology and chemistry of corrosion products on the surface of each material were evaluated using a combination of scanning electron microscopy,energy dispersive X-ray spectroscopy and X-ray diffraction and related to their overall corrosion protection.Results indicate that prior to the formation of protective films on the steel surfaces,the resistance of the materials to corrosion increase with increasing Cr content(Corrosion resistance:X65<1Cr<3Cr<5Cr).However,as corrosion products evolve,the protection afforded to the different steels significantly varies and decreases with increasing Cr content.×65 becomes the material with the lowest general corrosion rate by the end of the 192 h experiments and 5Cr exhibits the highest corrosion rate(ranking of corrosion resistance:X65>1Cr>3Cr>5Cr).In terms of the corrosion products on X65,both inner amorphous and outer crystalline corrosion layers consist of FeCO3.For the Cr-containing steels,the outer layer also comprises FeCO3,but the inner layer is enriched with Cr,and is predominantly amorphous Cr(OH)3.The extent of localised corrosion(determined using surface profilometry)is noticeably less for X65 compared to the Cr-containing steels.The paper raises questions about the benefits that low Cr steels offer towards extending component design life compared to carbon steel under the test conditions considered here.展开更多
传统的氯化铵浸取-重铬酸钾滴定法（邻二氮菲比色法）可有效分析试样中较高含量的碳酸铁（7.5%~80%）,但试剂消耗量大、测定步骤冗长、分析误差相对较大,水系沉积物中碳酸铁含量较低,采用此方法分析时其他含铁矿物的干扰易引入测量误差...传统的氯化铵浸取-重铬酸钾滴定法（邻二氮菲比色法）可有效分析试样中较高含量的碳酸铁（7.5%~80%）,但试剂消耗量大、测定步骤冗长、分析误差相对较大,水系沉积物中碳酸铁含量较低,采用此方法分析时其他含铁矿物的干扰易引入测量误差。本研究采用三氯化铝水浴加热浸取,建立了火焰原子吸收光谱法（FAAS）测定水系沉积物中低含量碳酸铁（0.1%~6.0%）的分析方法。使用80 m L浓度为100g/L的三氯化铝溶液水浴加热60 min,可完全浸取试样中的碳酸铁;在标准曲线中加入与待测样品浓度相同的三氯化铝,有效地避免了浸取剂三氯化铝的基体干扰。碳酸铁的检出限为0.015μg/m L,精密度为2.3%~4.0%（n=12）,加标回收率为95.0%~107.5%。沉积物中常见的含铁矿物（如赤铁矿和磁铁矿）对碳酸铁的测定干扰可忽略,磁黄铁矿的干扰可通过加入氯化汞消除。本法比传统化学分析方法的操作简便,准确度和精密度高,解决了其他含铁矿物的干扰问题。展开更多
Electrochemical techniques, X-ray diffraction （XRD）, and scanning electron microscopy （SEM） were applied to study the corrosion behaviors of X65 steel in static solution with carbon dioxide （CO2） at 65℃. The re...Electrochemical techniques, X-ray diffraction （XRD）, and scanning electron microscopy （SEM） were applied to study the corrosion behaviors of X65 steel in static solution with carbon dioxide （CO2） at 65℃. The results show that iron carbonate （FeCO3） deposits on the steel surface as a corrosion product scale. This iron carbonate scale acts as a barrier to CO2 corrosion, and can reduce the general corrosion rate. The protection ability of the scale is closely related to the scale morphological characteristics.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51671215)the Science Foundation of China University of Petroleum, Beijing (No. LLYJ-2011-41)the Ph.D Basic Research Innovation Foundation of China University of Petroleum, Beijing (No. 2462016YXBS06)
文摘The corrosion behaviors of X52, 3Cr low-alloy steel, and 13Cr stainless steel were investigated in an O_2–H2O–CO_2 environment at various temperatures and O_2–CO_2 partial-pressure ratios. The results showed that the corrosion rates of X52, 3Cr, and 13Cr steels increased with increasing temperature. The corrosion rates slowly increased at temperatures less than 100°C and increased sharply when the temperature exceeded 100°C. In the absence of O_2, X52, 3Cr, and 13Cr exhibited uniform corrosion morphology and Fe CO3 was the main corrosion product. When O_2 was introduced into the system, various forms of Fe_2O_3 appeared on the surface of the samples. The Cr content strongly influenced the corrosion resistance. The 3Cr steel with a low Cr content was more sensitive to pitting than the X52 or 13Cr steel. Thus, pitting occurred on the surface of 3Cr when 1.25 MPa of O_2 was added; this phenomenon is related to the non-uniform distribution of Crin 3Cr.
文摘Appropriate materials for injection pipelines and tubing for carbon dioxide geologic storage is fundamental to ensure asset integrity and save cost.This paper evaluates the corrosion behaviour of X65,1Cr,3Cr and 5Cr,which have the potential to be injection pipeline/tubing materials.The influence of steel Cr content on the general and localised corrosion behaviour was investigated at time periods from 6 to 192 h at 60℃and 100 bar.The evolution,morphology and chemistry of corrosion products on the surface of each material were evaluated using a combination of scanning electron microscopy,energy dispersive X-ray spectroscopy and X-ray diffraction and related to their overall corrosion protection.Results indicate that prior to the formation of protective films on the steel surfaces,the resistance of the materials to corrosion increase with increasing Cr content(Corrosion resistance:X65<1Cr<3Cr<5Cr).However,as corrosion products evolve,the protection afforded to the different steels significantly varies and decreases with increasing Cr content.×65 becomes the material with the lowest general corrosion rate by the end of the 192 h experiments and 5Cr exhibits the highest corrosion rate(ranking of corrosion resistance:X65>1Cr>3Cr>5Cr).In terms of the corrosion products on X65,both inner amorphous and outer crystalline corrosion layers consist of FeCO3.For the Cr-containing steels,the outer layer also comprises FeCO3,but the inner layer is enriched with Cr,and is predominantly amorphous Cr(OH)3.The extent of localised corrosion(determined using surface profilometry)is noticeably less for X65 compared to the Cr-containing steels.The paper raises questions about the benefits that low Cr steels offer towards extending component design life compared to carbon steel under the test conditions considered here.
文摘传统的氯化铵浸取-重铬酸钾滴定法（邻二氮菲比色法）可有效分析试样中较高含量的碳酸铁（7.5%~80%）,但试剂消耗量大、测定步骤冗长、分析误差相对较大,水系沉积物中碳酸铁含量较低,采用此方法分析时其他含铁矿物的干扰易引入测量误差。本研究采用三氯化铝水浴加热浸取,建立了火焰原子吸收光谱法（FAAS）测定水系沉积物中低含量碳酸铁（0.1%~6.0%）的分析方法。使用80 m L浓度为100g/L的三氯化铝溶液水浴加热60 min,可完全浸取试样中的碳酸铁;在标准曲线中加入与待测样品浓度相同的三氯化铝,有效地避免了浸取剂三氯化铝的基体干扰。碳酸铁的检出限为0.015μg/m L,精密度为2.3%~4.0%（n=12）,加标回收率为95.0%~107.5%。沉积物中常见的含铁矿物（如赤铁矿和磁铁矿）对碳酸铁的测定干扰可忽略,磁黄铁矿的干扰可通过加入氯化汞消除。本法比传统化学分析方法的操作简便,准确度和精密度高,解决了其他含铁矿物的干扰问题。
文摘Electrochemical techniques, X-ray diffraction （XRD）, and scanning electron microscopy （SEM） were applied to study the corrosion behaviors of X65 steel in static solution with carbon dioxide （CO2） at 65℃. The results show that iron carbonate （FeCO3） deposits on the steel surface as a corrosion product scale. This iron carbonate scale acts as a barrier to CO2 corrosion, and can reduce the general corrosion rate. The protection ability of the scale is closely related to the scale morphological characteristics.
