超级13Cr在H2S和CO2共存环境下的腐蚀行为影响研究

对CO2和H2S共存环境中95 ksi钢级超级13Cr钢的腐蚀行为进行了研究,发现常温条件下H2S和CO2共存环境中,无论是采用恒载荷的方法还是四点弯曲的方法,都在试样的表面出现了局部腐蚀,而在高温条件下未发生点蚀和应力腐蚀现象。分析结果表明,95 ksi钢级的超级马氏体不锈钢在常温H2S和CO2共存环境中出现的局部腐蚀主要是因为夹杂物在应力集中和酸性溶液的作用下形成点蚀,并沿着相同应力水平的区域扩展,局部腐蚀增加了应力腐蚀开裂的敏感性。     

CO2分压对油管钢CO2/H2S腐蚀的影响

采用高温高压釜、失重法和扫描电镜，对不同CO2分压(310．2642、930．7926、1551．3210、2171．8494kPa)条件下油管钢N80和P110的CO2／H2S腐蚀进行了研究。结果表明，随着CO2分压的升高，两种钢的CO2／H2S腐蚀速率均单调增加；除了CO2分压极低的情况以外，P110钢的腐蚀速率总是大于N80钢。     

3Cr抗CO2和H2S腐蚀系列油套管开发

CO2、H2S腐蚀是石油天然气开采过程中的主要腐蚀问题。文章在分析油井管CO2腐蚀行为和腐蚀特点的基础上，介绍了抗CO2、H2S腐蚀油套管的研制过程并开发出腐蚀性能良好的3Cr系列经济型油套管。文章重点介绍了80、95、110等不同钢级成品管的力学性能，抗CO2、H2S应力腐蚀开裂性能。运用SEM扫描电境、X光电子能谱仪、X射线衍射、体视显微镜等分析了钢经腐蚀后的表面腐蚀产物的组成、结构，并对Cr元素改善钢的抗CO2腐蚀行为及机理进行了分析。     

BT80SS抗H2S腐蚀石油套管的研制

根据化学元素对H2S应力腐蚀的影响,选用C,Mn,Cr和Mo为合金元素,控制S和P等有害元素的含量,同时加入RE;根据钢管的组织对抗H2S应力腐蚀的影响,采用淬火后高温回火的热处理制度,生产出了具有自主知识产权的抗H2S套管,该产品具有良好的耐H2S腐蚀性能。     

L245钢抗SSC、HIC的性能试验

采用NACETM0284—2003和NACETM0117—2005实验方法对L245钢进行评定。结果表明：在湿心S环境下,L245钢具有良好的抗氢致开裂（HIC）和硫化氢应力腐蚀（SSC）的能力。在试验结果基础上,对其腐蚀机理及影响因素进行了讨论。     

温度对API—X60管线钢HeS／CO2腐蚀行为的影响

利用高温高压反应釜模拟高含硫气田H2S／CO2共存环境,在流动溶液介质中进行腐蚀试验,辅以扫描电子显微镜和X射线衍射仪等研究手段,探讨了温度对API—X60管线钢H2S／CO2腐蚀行为的影响。结果表明,随着温度的升高,API-X60管线钢的腐蚀速率先升高后降低,腐蚀形态由局部腐蚀趋于全面腐蚀,高温区有点蚀倾向。低温时形成的腐蚀产物以马基诺矿型晶体和铁的单硫化物为主,随着温度的升高,腐蚀产物以层片状马基诺矿型晶体为主,并出现少量磁黄铁矿型晶体,高温区则以磁黄铁矿型晶体为主。低温区点蚀的发生是由于腐蚀产物附着力差导致其覆盖率降低,膜层覆盖处的阴极效应促进了局部腐蚀。     

7%Cr管线钢在含有CO2盐溶液中的腐蚀行为研究

摘要：利用失重法,结合显微形貌、能谱分析、X射线衍射、电化学测试等手段,分析了中铬钢在高温高压含有CO2的盐溶液环境中腐蚀的萌生与发展,以及热处理工艺对中Cr钢的耐蚀性能影响规律。结果显示：7%Cr（质量分数）钢在有CO2的盐溶液中的腐蚀以点蚀为开端,随后形成由Cr(OH)3和FeCO3组成的非晶态产物膜,产物膜外层有颗粒状FeCO3附着,随着Cr(OH)3的大量产生产物膜中部分FeCO3溶解,随后CaCO3沉淀填补了颗粒状FeCO3溶解后留下的空隙。热处理后淬火试样耐蚀性最好,正火次之,轧制试样最差。     

低碳中铬钢在模拟CO2-EOR环境下的腐蚀行为

 为了研究Cr5和Cr7(质量分数/%)钢在CO₂-EOR高温高压服役条件下的腐蚀机理,利用高温高压反应釜模拟其腐蚀行为,使用失重法测定了腐蚀速率,采用SEM、EDS、XRD和XPS等手段对腐蚀产物进行了观察与分析,探讨了试验钢在CO₂条件下的腐蚀机理,并提出了腐蚀模型。研究结果表明,Cr5钢的腐蚀速率为0.734 75 mm/a,Cr7钢的腐蚀速度为0.217 32 mm/a;腐蚀产物均由外层的FeCO₃晶体以及内层的非晶态FeCO₃和Cr(OH)₃组成;腐蚀初期,产物膜以原位形成和阳极溶解后逐渐沉积两种途径生成;产物完全覆盖基体后,离子在界面处的扩散后沉积成为产物膜生长的主要途径。     

高含H2S和CO2环境中L80钢的腐蚀规律

 采用失重腐蚀方法研究了在模拟气田井下腐蚀环境中腐蚀影响因素(总压力、温度、腐蚀时间、H2S、Cl-、溶液流速),对套管钢(L80)腐蚀的影响规律,并用扫描电镜分析了腐蚀产物膜形貌。结果表明：60 ℃为L80钢在H2S+CO2腐蚀环境中的腐蚀临界温度,此时,L80钢的腐蚀速率最小;当总压力大于等于9 MPa,温度为120 ℃,H2S、CO2达到各自的超临界点,L80钢的腐蚀速率比温度为90 ℃时小;随腐蚀时间延长,腐蚀速率明显下降;相对在单一的CO2环境下,引入H2S可降低腐蚀速率;Cl-可促进L80钢的腐蚀;溶液流速加快,腐蚀速率提高。     

SSC抗硫化氢应力腐蚀试验方法的开发

文章通过对硫化氢基础特性及油套管硫化氢腐蚀机理的研究探讨,结合NACE TM0177-2005和ASTM A370标准要求,提出了符合企业生产要求的SSC抗硫化氢应力腐蚀试验方法。将该方法应用在现场生产硫化氢腐蚀专用油套管SSC检验过程中,取得良好的应用效果,为企业创造了较高的经济效益与社会效益。     

Investigation of Mechanical Property of Oil Tube Steel P110S in High Temperature and High Pressure Environment Containing H2S/CO2

With the exploitation of high sour and deep oil well in china,the corrosion medium containing CO 2,H 2 S,Cl-and organic acid threaten the safety of oil equipment and tube steel severely.In this article,many experiments,including corrosion tests,tensile tests,hydrogen concentration measurement tests and SEM examinations,were performed to investigate the effect of H 2 S partial pressure and loading stress on the mechanical property of oil tube steel P110S in high temperature and high pressure environment containing H 2 S/CO 2.The tensile strength and yield strength during fracture process of P110S steel were obtained experimentally and the fracture morphology was analyzed by SEM.The results indicate that both tensile strength and yield strength decreased after corrosion.The damage of tensile strength and yield strength became serious with an increase in H 2 S partial pressure and loading stress.According to the fracture analysis,the fracture mode exhibited quasi-cleavage and dimple mixed fracture,and the area of quasi-cleavage pattern increased with H 2 S partial pressure and loading stress increasing.According to the results of tensile test and hydrogen concentration measurement test,the tensile property degradation is closely associated with diffusible hydrogen concentration of P110S steel in the H 2 S/CO 2 environment.     

Corrosion Behavior of 110S Tube Steel in Environments of High H2S and CO2 Content

 The corrosion behavior of the 110S tube steel in the environments of high H2S and CO2 content was investigated by using a high-temperature and high-pressure autoclave, and the corrosion products were characterized by scanning electron microscopy and X-ray diffraction technique. The results showed that all of the corrosion products under the test conditions mainly consisted of different types of iron sulfides such as pyrrhotite of Fe0. 95S, mackinawite of FeS0. 9, Fe0. 985S and FeS, and the absence of iron carbonate in the corrosion scales indicated that the corrosion process was controlled by H2S corrosion. The corrosion rate of the 110S steel decreased firstly and then increased with the rising of temperature. The minimum corrosion rate occurred at 110 ℃. When the H2S partial pressure PH2S below 9 MPa, the corrosion rate declined with the increase of PH2S. While over 9 MPa, a higher PH2S resulted in a faster corrosion process. With the increasing of the CO2 partial pressure, the corrosion rate had an increasing trend. The morphologies of the corrosion scales had a good accordance with the corrosion rates.     

Influence of Chromium on Mechanical Properties and CO2/H2S Corrosion Behavior of P110 Grade Tube Steel

Four kinds of P110 grade tube steels containing different chromium contents were designed to probe the in- fluence of Cr on the properties of tube steel. The microstrueture, mechanical properties and corrosion behavior of the four kinds of P110 grade tube steels were studied deeply and thoroughly. The analysis of the mechanical properties indicated that tensile strength and yield strength of the steel plates were improved, while transverse and longitudinal impact energy and elongation first increased and then decreased when Cr content rose. The impact energy and elonga tion reached the peak when Cr content was 1 ~. Cr precipitates were found only in 3 ~ Cr steel, with （Nb, Ti）（C, N） or Nb（C,N） as the core of precipitation and then grew up. The corrosion experiments demonstrated that the scales on the four steels had a two layer structure under the corrosion of CO2 and H2 S. The outer layer was mainly com- posed of FeS or FeS1 x and the inner layer consisted of FeCOa and Cr compounds. Cr was rich in the inner layer and the Cr content of the inner layer increased with the Cr content in matrix. The enriched Cr enhanced the compactness of the scales, further hindering the diffusion of ions from liquid to the surface of steel, thus reducing corrosion rate.     

Corrosion behavior of super 13Cr stainless steel in a H_2S and CO_2 environment

The corrosion behavior of 95 ksi grade super 13 Cr stainless steel in an environment consisting of H_2S and CO_2 was investigated.The results reveal that for both loading methods(constant load and four-point bending),local corrosion occurred on the surface of the samples tested at ambient temperature but was absent from the samples tested at high temperatures.The local corrosion was caused by the formation of pits at nonmetal inclusions; the pits were formed under the action of stress in an acidic environment, which was due to an acid solution.Subsequently, the corrosion extended along the direction of stress.The sensitivity of stress corrosion cracking increased because of the local corrosion.     

Effect of CO2 partial pressure on corrosion of 3Cr steel in high temperature steam environment

To study the effects of CO2 pressure on 3Cr steel in the high temperature steam environment. The corrosion tests were conducted in a HTHP autoclave to simulate the CO2 auxiliary steam drive. 3Cr steels were subjected to weight loss test under the condition of CO2 partial pressure range of 1-4MPa at 160??. The corrosion morphology and product composition were explored by SEM, EDS, XRD and XPS. The results show that the corrosion rate of 3Cr steel is lower than the corrosion control line of oil field (0. 076mm/a). With the increase of CO2 partial pressure, the corrosion rate firstly increases and then decreases. When the CO2 partial pressure is 1-2MPa, the FeCO3 generated by corrosion process gradually deposits on the surface of steel, and the number of FeCO3 crystals gradually increases. When the CO2 partial pressure is 3-4MPa, a small amount of FeCO3 crystals in the corrosion products dissolves, and the corners of FeCO3 crystals become rounder and the corrosion products become more compact. The results show that CO2 partial pressure mainly affects the deposition and dissolution of FeCO3 in the high temperature steam containing CO2 environment, which influences the protective properties of 3Cr steel corrosion products, thus further affecting the corrosion rate.     

油管钢高温高压CO2腐蚀行为研究

在高温高压条件下，对P110，N80，J55三种油管钢在模拟油田CO2环境下的腐蚀性能进行了研究评价，结果表明：在静态条件下，三种钢对温度和压力的依赖关系均为类似抛物线规律，P110最不耐蚀，动态条件下对P110钢的进一步研究显示，由于流速的存在，与静态下相比，最高均匀腐蚀速率点向温度和CO2分压升高的方向移动。