液氨储罐简体腐蚀原因分析及防范措施

本文对某化肥分公司液氨储罐筒节进行了宏观检验、仪器壁测定、表面检测和强度校核,并根据实际检验情况对液氨储罐筒节腐蚀减薄原因进行了分析。结合实际情况对液氨储罐提出了防腐措施。     

海上风电塔筒的防腐涂装及应用实例

针对广东徐闻海上风电项目塔筒的防腐涂装及应用实例,分析了海上风电塔筒所处的腐蚀环境,提出海上风电塔筒的防腐技术方案和施工工艺,并对涂层施工质量的检测和控制进行了探讨。     

协同处置回转窑筒体腐蚀及处理措施

介绍了Φ4.8m×72m的协同处置固废水泥熟料生产线回转窑筒体的腐蚀跟踪情况，防腐采取的措施，腐蚀性裂纹临时处理措施，对腐蚀严重的部分筒体更换方案，确保回转窑的安全运行。     

硝铵造粒塔的防腐技术

针对硝铵造粒塔在运行中出现的腐蚀情况， 介绍了外壁混凝土裂缝灌浆、筒壁内部防腐、操作室隔墙的更换及防腐、混凝土及钢结构的防腐和排水系统的改造等防腐技术及措施， 实施效果良好。     

快装锅炉的局部腐蚀探析

通过分析锅炉局部腐蚀的腐蚀机理 ,指出快装锅炉的锅炉筒后端下部、锅炉筒水位线附近和两侧集箱后端下部是最容易发生局部腐蚀的地方 ,这些局部腐蚀与锅炉水质、锅炉的结构、运行方式及维护保养等有关 ,可通过改进设备、提高防腐技术、规范操作和加强锅炉的维护保养等手段来减缓上述部位的局部腐蚀。     

火电厂烟囱玻璃钢内筒正装法施工方法

在火电厂烟囱内筒施工中,常用的方法为烟囱内部逐节顶升或者提升,从上到下逐节安装的倒装法,采用正装法施工的较少见。文章结合通辽发电总厂1#烟囱内部防腐改造施工经验,介绍自立式玻璃钢防腐内筒外部起吊,内部正装法施工方法。     

快装锅炉的局部腐蚀探析

通过分析锅炉局部腐蚀的腐蚀机理，指出快装锅炉的锅炉筒后端下部、锅炉筒水位线附近和两侧集箱后端下部是最容易发生局部腐蚀的地方，这些局部腐蚀与锅炉水质、锅炉的结构、运行方式及维护保养等有关，可通过改进设备、提高防腐技术、规范操作和加强锅炉的维护保养等手段来减缓上述部位的局部腐蚀。     

尿素合成塔衬里腐蚀寿命分析及衬里更换

氨汽提工艺尿素合成塔衬里腐蚀主要发生在第1、2筒节衬里,对减薄衬里进行寿命分析,尿素合成塔上封头瓜皮、第1筒节衬里、第2筒节衬里在衬里下一轮大修时必须更换。根据尿素合成塔的结构特点,提出切割上封头整体更换衬里的思路和方法。     

二氧化碳吸收塔腐蚀的原因分析及对策

针对本菲尔脱碳工艺流程中二氧化碳吸收塔下部筒节出现的严重腐蚀问题,经分析认为是冲刷和碱性溶液对金属材质侵蚀性腐蚀所致。对二氧化碳吸收塔腐蚀带进行切割补焊、消除设备缺陷并加强相应的管理措施后,稳定了脱碳工序的生产。     

浅议尿素合成塔在线检漏方法

尿素合成塔多采用层板包扎结构。由于尿素合成塔内尿素和氨基甲酸铵溶液泄漏后对强度层（多为15MnVR或16MnR）腐蚀速度非常快,为防止强度层因腐蚀失效,在顶盖和筒节上分别设计了检漏孔（结构如图1所示）,以便早期发现尿素合成塔内筒泄漏,避免恶性事故的发生。     

外围油田埋地金属管道腐蚀穿孔原因及控制建议

管道作为大量输送石油、水、气体等介质的最为安全经济的方法在油田得到广泛应用,而输送油、气的管道大多处于复杂的土壤环境中,所输送的介质也多有腐蚀性,因而管道内壁和外壁都可能遭到腐蚀。据统计,采油九厂在2008、2009年平均每年更换腐蚀老化管线10.25 km,而在2010年更换腐蚀老化管线达到了15.195 km,可以说管线腐蚀问题,已经严重的影响到油田的正常生产。本文对龙虎泡油田腐蚀管线的成因进行分析并对采油九厂阴极保护实施效果进行评价,得出了外围油田埋地金属管道腐蚀穿孔的主要原因,并提出了相应的腐蚀穿孔控制建议,为管道安全输送提供技术保障。     

Microstructure and plasma corrosion behavior of yttria coatings prepared by the aerosol deposition method

Particle contamination arising from inner ceramic components of the plasma etching equipment has become a serious issue. Yttria (Y₂O₃) coatings prepared via aerosol deposition (AD) have demonstrated superior plasma resistance in the reduction of particle contamination. The superior particle contamination performance of Y₂O₃ coatings prepared by AD has been speculatively attributed to its unique microstructure; however, the relationship between the coatings’ microstructure and plasma corrosion behavior has been insufficiently clarified. Herein, we investigated the relationship between the microstructure and plasma corrosion behavior of Y₂O₃ coatings prepared by the AD method and compared the results with those for coatings prepared by other coating methods. When internal pores are present, these internal pores were selectively plasma corroded; plasma corrosion marks reflecting their pore shape were formed, and the surface roughness increased with increasing plasma exposure time. However, when no internal pores were present, as in the case of the AD coating, the surfaces were homogeneously corroded and maintained their initial surface. As the risk of particle contamination caused by the corrosion of the plasma-resistant coatings is greatly increased with surface roughness, we concluded that the Y₂O₃ coating prepared via AD will contribute greatly to reducing particle contamination.     

液化气球罐Zare合金防护层涂装工艺

液化气球罐在使用过程中因球罐内壁存在SSCC(硫化物应力腐蚀开裂)腐蚀环境,造成球罐内壁焊道热影响区出现裂纹,导致球罐内壁腐蚀.本文介绍了采用涂覆稀土合金(Zare)涂层和封闭剂的方法解决液化气球罐内壁SSCC腐蚀问题,着重讨论了球罐内壁防腐涂装工艺及其注意事项.     

火炬管线腐蚀分析与防护措施

碳钢火炬管线使用10年后，发现管线底部出现腐蚀，管内壁上面覆着大面积腐蚀产物，腐蚀减薄严重，甚至局部腐蚀穿孔，蚀孔由管内向管外方向扩展。对腐蚀气分火炬管线及管内壁腐蚀产物进行技术检测，解析腐蚀原因，进而提出防护措施。     

An experimental study on the bond strength between reinforcement bars and concrete as a function of concrete cover,strength and corrosion level

The effect of corrosion on the bond strength between reinforcement bars and concrete was studied in a series of experiments. An accelerated corrosion method was used to corrode the reinforcement bars embedded in concrete specimens. Pullout tests were performed to develop an empirical model for the ultimate bond strength by evaluating bond strengths in two different concrete mixes, three concrete cover depths and different mass losses of reinforcement bars after corrosion. Bond-slip relationships for the different corrosion levels were compared. It was found that the relationship between bond strength and concrete strength in uncorroded specimens differed from that of corroded specimens set in high-strength concrete because of brittleness in the corroded specimens, which caused a sudden loss of bond strength. The results revealed that specimens with higher concrete strength levels and corroded reinforcements showed a higher percentage of bond strength degradation due to concrete cracking during the pullout tests.     

T23,T24合金管材在模拟烟气中的高温腐蚀研究(英文)

Candidate materials for water wall of supercritical and ultra-supercritical utility boilers,T23 and T24,were chosen as the experimental samples and exposed to oxidizing atmosphere,reducing atmosphere and oxidizing/reducing alternating atmosphere separately.The corrosion temperature was 450-550?C.The effects of oxygen con-tent and temperature on the corrosion in reducing atmosphere and alternating atmosphere were investigated.The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) were used to examine the corroded samples.The results show that the corrosion kinetics of T23 and T24 can be described by the double logarithmic equation and parabolic equation respectively.To describe the corrosion of materials accurately it is not sufficient to analyze the macro-mass gain and the macro-thickness of the corroded layer only,but the EDS should be applied to examine the migration depth of corrosive elements O and S.It is revealed that the corrosion becomes more severe when H2S is present in the corrosive gas.S is more active than O,and Cr can reduce the migration of oxygen but not S.The combination corrosion of S and O and pure [S] has a stronger corrodibility than pure H2S.T24 suffers the most severe corrosion at oxygen content of 0.8%.Corrosion is aggravated when the corrosion temperature is above 450 ℃ in the alternating atmosphere.T23 has better corrosion resistance than T24 and W contributes a lot to the corrosion resistance of T23.     

数值模拟研究螺筒结构对单螺杆挤出机性能的影响

通过数值模拟研究了机筒内壁开螺槽的螺筒结构对单螺杆挤出机性能的影响。采用POLYFLOW软件模拟了硬质聚氯乙烯(PVC-R)熔体在单螺杆螺筒挤出机以及传统单螺杆挤出机中的三维等温流场及混合过程,并对二者的混合挤出性能进行了比较。结果表明:机筒内壁为螺旋沟槽结构的单螺杆螺筒挤出机,其混合性能相对于传统单螺杆挤出机有所提高。     

Using Rheology to Achieve Co-Extrusion of Cement-Based Materials with Graded Cellular Structures

Co-extrusion involves simultaneous extrusion of multiple layers and can be used to produce functionally graded materials whose layers have different properties. Rheological control is vital for successful co-extrusion. During extrusion, flow in the barrel and die land in a ram extruder should be plug-like, while the paste should be sheared and uniformly elongated in the die entry region. In the barrel of the extruder, the paste flow velocity field was inferred by direct observation of the paste left in the barrel, and evidence for plug flow in the barrel was seen only at low-extrudate velocities. In the die land, the Benbow nonlinear model was employed to assess the paste flow behavior, and plug flow was achieved only when the shear stress applied to the paste by the die land wall was smaller than its yield stress. For co-extrusion, a simple method using thin-walled tubes was found to be effective to prepare layered feedrods. Functionally graded cellular structures of cement-based materials were successfully co-extruded by using a low-extrudate velocity when the paste had decreasing shear viscosity from inner to outer layers.     

Hot corrosion of cordierite/mullite composites by Na-salts

Cordierite/mullite (C/M) ceramic composites were corroded by NaCl and Na₂SO₄ at 1000 °C for 24 h. The predominant corrosion products in attack by the Na-salts were found to be nepheline and carnegieite for the cordierite and mullite component, respectively. NaCl attacked both components with different corrosion rates, producing corrosion layers consisting of two distinct regions where both cordierite and mullite were chemically attacked near the surface region and only the cordierite phase was damaged in the succeeding inner part. In the hot corrosion by Na₂SO₄, on the other hand, only the cordierite component was severely attacked in the composites, resulting in occurrence of selective corrosion. Thus, the corrosion of the C/M composites by the Na-salts proceeded through the path of the less resistive cordierite component at 1000 °C in air.     

旧煤气管线改作天然气管线前清洗的重要性

论述了旧煤气管线改作输送天然气管线前,清除管线内壁焦油类沉积物及锈蚀产物的必要性,通过测定碳钢在四氢噻吩(THT)-石油醚溶液中的腐蚀性能,揭示残存的焦油能吸收添加在天然气中的THT,造成THT在管线输送过程中的额外损耗,并与此同时对送气管线构成一定的腐蚀.采用腐蚀挂片试验与XPS表面成分分析发现,在锈蚀的碳钢表面总伴有大量的含硫化合物吸附富集,吸附与锈蚀共存,二者是相互促进的关系.碳钢管线内壁发生腐蚀,也会引起THT的额外消耗,对清除旧煤气管线内壁的焦油和铁锈,提出了建议.