全面分析管道三层PE防腐层缺陷（三）：表观质量缺陷

三层PE防腐层的表观质量缺陷的存在,在大多数情况下会造成管道运行隐患。本文列举了三层PE防腐层常见的表观缺陷,并通过分析,来进一步提高三层PE的防腐质量。     

全面分析管道三层PE防腐层缺陷（二）：焊缝防腐层缺陷

本文分析了三层PE外防腐钢管焊道区防腐层缺陷的种类、形成原因及其影响因素，提出了防止和控制缺陷形成的技术工艺措施。     

3PE防腐层缺陷成因分析与防范

3PE防腐层被称为“完美”涂层。但是，由于其涂装技术相对比较复杂，如果生产工艺控制不严，将会产生多种防腐层缺陷；另一方面，剥离的聚乙烯层对阴极保护电流具有很强的屏蔽作用，3PE的某些缺陷有可能是致命的。本文对3PE防腐层缺陷产生原因进行了较为全面的介绍和分析，同时提出控制措施，与业内同行交流。     

管道三层结构聚乙烯防腐层的优化

管道三层结构聚乙烯防腐层具有优异的综合防腐性能，是当今国际先进的管道外防腐技术之一，防腐层的厚度直接影响着它的机械性能、防腐性能、耐化学性能、良好的施工性能和经济性，因此防腐层的厚度倍受人们关注。本文扼要阐述了国外三层聚乙烯防腐层最小厚度确定的依据，国内应用情况调研，焊缝部位防腐层厚度试验检测；提出防腐层厚度在没有充分理论依据和实际经验的条件下，不能只从经济角度考虑，将防腐层厚度减薄。根据涂敷试验结果。在目前涂敷工艺条件下，焊缝处防腐层厚度与管体防腐层厚度的差异规定在70％较合适。     

全面分析管道三层PE防腐层缺陷（五）：质量控制

本文从三层PE的生产工艺入手，通过生产过程、涂覆步骤以及相关设备等分析，阐述了三层PE防腐层成型过程中的质量控制。     

全面分析管道三层PE防腐层缺陷（一）：翘边缺陷

本文分析了钢管三层PE外防腐成型过程中形成翘边缺陷的原因及其影响因素，提出了防止和控制翘边缺陷形成的技术工艺措施。     

三层PE防腐层涂敷中出现废层的原因及采取措施

三层PE防腐层是目前广泛采用的钢质管道外防腐层，由于其涂敷过程中出现问题，会造成不合格产品，影响防腐管道的寿命。本文简要阐述了产生不合格三层PE防腐层的原因，提出了改进意见。     

管道外防腐层抗划伤性能研究

在当前的管道建设中，熔结环氧粉末防腐层(FBE)、三层聚乙烯防腐层(3-PE)和双层环氯粉末防腐层(DPS)是最常用的外防腐层，然而在敷设过程中发现外防腐层受到的划伤极为严重，冯庆善、李获两位专家在本文中根据管道施工过程中，管道外防腐层经常被划伤这一现象，针对外防腐层的耐划伤性能进行研究，以达到控制质量、提高使用寿命的目的。研究结论的应用将显著提高管道外防腐层的抗机械损伤性能，保证了防腐层的一体性和管道运行寿命。同时，对降低工程造价、改善涂层结构具有指导意义。     

坨—鞍输油管道防腐层检测与修补

坨－鞍输油管道采用泡沫黄夹克防腐保温，在运行过程中对管道防腐层进行检测并进行修补，保证管道运行，提高企业的经济效益。     

长输管道不停产防腐层大修技术

东河塘至轮南输油管道，经过8年的运行，钢管外石油沥青玻璃布防腐层已老化严重甚至剥离。在不停输的情况下，对输油管道防腐层大修，特别像东-轮输油管道，地处沙漠边缘、戈壁地带，没有成熟的施工经验用以借鉴。本文就输油管道防腐层大修工艺、质量保证措施等具体内容，论述了长输管道不停产防腐层大修技术成功的经验。     

Defects in CVDZnS

Defects seriously influence the optical properties and mechanical properties of CVDZnS.The deposition technique was introduced and experiment methods such as SEM,TEM and OM were adopted to study the defects:hexagonal phase,abnormally large grains,micro-cracks,micro-pores and impurities.The microstructures of these defects were observed,and the formation mechanisms of these defects were analyzed.Hexagonal ZnS as an impurity causes anisotropy in different directions with different refraction indexes and increases the scattering of CVDZnS.Increasing the deposition temperature can inhibit the formation of the hexagonal phase.The main reason for the growth of abnormally large grains in CVDZnS is high deposition rate.The lower deposition temperature increases growth stress in CVDZnS,which consequently results in the bowing of CVDZnS plates,and introduces microscopic defects such as grain blending and micro-cracks in the crystal.Micro-pores and impurities are induced by high reactant concentration in the local deposition chamber,which can be avoided by improving the gas flowing so as to make the concentration more uniform.     

铸铁件常见铸造缺陷的防止方法

铸铁件常见的铸造缺陷有：气孔、砂眼、渣孔、缩孔、缩松、粘砂、裂纹、变形、硬度不均匀、球铁件球化不良、球化衰退、石墨漂浮和反白口等。介绍各种缺陷的产生原因以及它们的防止措施。     

Defects in Nickel-Base Superalloys

In the sixty years since age-hard-enable, nickel-base superalloys were first identified, the compositional and microstructural features of these high-performance metals have changed markedly—from the early Nimonic (INCO trade name) 80A (a wrought alloy of essentially four elements) to today’s family of wrought from ingot, powder metal, cast and directionally cast alloys. As a result of physical property refinements, the alloys’ characteristics can be tailor fit to specifically defined applications. With this range of possibilities available, it is necessary to consider the appearance and implications of microstructural defects—defects which have accompanied advances in processing and materials selection. As new alloys and processes are developed, industry must correspondingly commit to identifying and controlling new defects.     

镀锌板纵向色差缺陷成因的有限元分析及控制

针对某冷轧厂光整机生产极限宽度规格的镀锌板产生纵向色差的问题,基于有限元方法,建立了四辊光整机的辊系模型,分析了纵向色差产生的原因,并进一步对支撑辊辊型进行了局部优化。随后的生产实践证明,优化后的辊型解决了纵向色差问题,提高了光整质量和轧辊的使用寿命。     

用粘合剂修补铸件缺陷

介绍了粘合剂的组成配比,分析了修补铸件砂眼、气孔等缺陷的方法。     

超声波探伤中缺陷波和伪缺陷波的判别

超声波探伤是目前应用最广泛的无损探伤方法之一，它具有灵敏度高、穿透能力强、检验速度快、成本低、设备轻便和对人体无害等一系列优点。超声波在钢材内部穿透能力很强，因此可检测很厚的钢板和焊缝；对于平面状缺陷，尽管有的缺陷很深，只要超声波直射至缺陷面，均能得到很高的缺陷波。因而超声波对压力容器焊缝探伤未焊透和裂纹等危险性缺陷检测灵敏度很高，具有实用意义。检测中作好缺陷和伪缺陷的判别具有重要意义。     

ASEM Analysis of Casting Defects

While casting defects are a fact of life in the foundry, a method has been developed for analyzing these defects by employing analytical scanning electron microscopy (ASEM). The use of a backscattered electron detector and energy dispersive x-ray systems, available on most ASEM’s, facilitates the examination of various defects. Computer storage and programming can make analysis of many particulate defects a routine procedure. Overall, the method provides a starting point from which a person with a knowledge of the process can begin to quickly diagnose the cause of defects. Examples of the usefulness of the technique are presented using case histories from a grey iron foundry.     

Common Defects in Nickel Deposits

Investigations have been carried out on the corrosion resisting properties and thicknesses of black oxide coatings produced from a solution of sodium hydroxide, sodium nitrate and sodium dichromate. Methods of measuring the film thickness are described, which indicate that it is of the order 0·00005”-0·0001”.

Corrosion tests show that the protective value of the coating is higher on steels containing nickel and chromium, even in amounts as low as 1%, than it is on plain carbon steels, when tested by immersion in fuels and water. In the case of tests made in the humidity chamber the protective value of the oxide film on all the samples tested was negligible.

X-ray diffraction examination showed that the coating consisted of Fe₃O₄ on all steels, but on those containing 3% chromium or more traces of Cr₂O₃ were also found.     

Defects in Strained Layer Semiconductors

The improvement in vacuum deposition technologies such as molecular beam epitaxy (MBE) and metallorganic chemical vapor deposition (MOCVD) has enabled the latticemismatched, pseudomorphic growth of epitaxial systems. These strained layer systems allow for a wide flexibility in tailoring semiconductor heterostructures for certain electronic band gaps. To the materials scientist, this means a wider choice of materials in this field of “band-gap engineering.” As in any engineering application of materials, defects play a major role in materials fabrication and device performance. This paper considers some of the unique features of defects in strained layer semiconductors—both process- and service-induced.