超高强度管线钢管X120的开发

天然气的重要性已受到人们的高度关注,但必须降低其远距离输送成本,采用高压操作、小口径薄壁干线用管是有效的办法,为此需要高强度管线钢.新日铁与世界最大的油气公司ExxonMobil公司合作开发了强度等级超过以往的X65和X80的超高强度大口径管线钢管X120.X120的生产技术要求比X65和X80更高.双方在材质设计、炼钢、浇铸、钢板生产和钢管生产(UOE成型和焊缝技术)等方面进行了系统的研究开发,完成了包括小批量生产在内的钢管开发和使用性能评价,并对管线敷设时的现场环焊实用技术等进行了综合开发.研究分析证明,X120的商业化生产是可行的.     

天然气输送管件三通用X90钢板的开发

在中石油计划建设西气东输三线X90/X100管线钢试验段背景下,舞钢成功开发天然气输送管件三通用X90钢板,钢板由中油管道局机械制造厂制作成三通并经西安管材所检验,各项性能指标均符合X90管线钢三通的要求。     

低温韧性优良的管线用X80电焊钢管开发

由于近年提高了对能源输送的需要，即使是在电焊钢管中，为了满足对高强度高韧性管线输送用钢管的需求，已经实现了X80级高韧性电焊钢管的商品化。开发钢管组织中不含粗大的珠光体（简称P）和马氏体（简称M）、而具有均匀的贝氏体·铁素体（简称B·F）组织。另外，将c（碳）含量降至0．03％的低Ceq（c当量）成分钢缝焊部韧性优良，特别是不仅母材，而且即使焊接部位的vTrs（夏比断口转变温度）也低到了50℃以下，从而使X80级电焊钢管韧性优良，能满足多方向管线钢的用途要求。     

中亚管线用X70级螺旋钢管的研制

介绍了浙江金洲管道工业有限公司X70级SAWH钢管的研制开发工作及试制过程.结果表明,通过对钢管管材选材优化,生产工艺流程开发及优化,所研制的中亚管线用X70级SAWH钢管管体抗拉强度约为700 MPa,断后伸长率最小值为39 %,屈强比在0.72~0.77之间.钢管焊缝经腐蚀,焊区未见明显宏观焊接缺陷.这表明所开发的...     

显微组织对管线钢屈强比和低温韧性的影响

石油天然气输送管线钢须具备高强度、高韧性、优异耐蚀性和高焊接性。当今,要求用大口径、高压管线来改善输送效率,这就需对管线钢有更高强度的技术要求。此外,从安全性考虑,管线钢需有低屈强比,     

新一轮天然气管线建设的特点

<正>新一轮干线天然气管线建设将具有输送距离长,采用更高工作压力和大管径输送的特点。当前国际上新一轮巨型天然气长输管道、单管输气量将达到450亿~500亿m3/a的水平。干线一般采用X80钢级。一个具有代表性的项目是正在建设的俄罗斯巴甫年科沃———乌恰天然气管道。管线长度1100km,采用1420mm管径和K65(类似于X80)钢级,输送压力11.8MPa,单管设计输气量约500亿m3/a,计划于2012年三季度进行系统调试。     

提高X70和X80高强度管线钢板屈服极限的可能性

1前言 制管工厂在订购大直径电焊管所用的厚钢板合同中，要求钢板的屈服极限比钢管基本金属的屈服极限高约30N／mm^2。这是因为在制管过程的成形、扩径和机械性能试验中，由于在正反交替的塑性变形影响下出现的“包辛格尔效应”，使屈服极限下降。这种行为是用铁素体-珠光体钢制成的钢管所特有的，X70（K60）强度级的钢和强度低一些的钢都属于这类钢。当改用X80（K65）强度级的和强度高一些的铁素体-贝氏体类钢制做钢管，就会发现制管过程对钢管的强度有不同的影响：特别是在一定条件下，可以观察到屈服极限有明显的提高。     

TSE550级（X80）大口径管线钢的现状,开发和认证

为了寻求达到天燃气输送系统的安全、可靠和成本低、效益好的目标 ,管线设计是一个需慎重考虑的问题。对天然气增长的需求导致了采用大口径 (在法国为 Φ91 4mm)钢管 ,同时壁厚也适合工作压力 ,这类钢管有 TSE 480 ( X70 )级钢板制造。为了获得优质和更高级别管线钢 ,新钢级的开发得到了鼓励 ,为了降低成本和优化焊接性能 ,还限制了微合金元素的添加。由于这些技术方面的进步 ,EN1 0 2 0 8标准(用于天然气管线钢种 )也在欧洲标准的范围内作了修订。新标准反映了过去 2 0年大口径钢管的开发。该文涉及推荐 L5 5 5 MB级 (“TSE 5 5 0”,…     

太钢研制成功X120管线钢卷板

日前,世界上等级最高的X120管线钢卷板在太钢2250热轧生产线试制成功,太钢成为全球首家实现X120管线钢卷板试生产的企业,也是太钢管线钢技术继X80管线钢之后的又一次重大突破。管线钢主要应用于石油、天然气输送管道的制造,由于天然气田大多集中在荒漠、极地冻土带等边远地区,对管线钢的可靠性和经济性要求极高,     

X70级大壁厚海底管线钢板的研制开发

介绍了舞钢研制X70级海底管线钢板的成分设计思路、工艺控制及产品实物性能。通过低碳、铌钛微合金化、复合添加镍钼等合金元素的成分设计以及合理的TMCP工艺控制,得到比例合理的软相多边形铁素体和硬相贝氏体组织,生产出屈强比控制在0.85以下的30.8 mm厚度X70级海底管线钢板。钢板经过卷制、焊接、检测,完全符合深海天然气输送用管线钢的要求。     

Magnetic and other physical properties of X 52, X 60, X 70, and X 80 grade linepipe steels

The following magnetic properties were determined for X 52, X 60, X 70, and X 80 grade linepipe steels: magnetic induction as a function of magnetic field strength in the form of hysteresis loops, coercive force and saturation magnetisation. In addition, the following physical properties were determined: coefficient of thermal expansion between -180 and 400°C, elastic constants between -180 or 20 and 300°C, electrical resistivity, thermal conductivity and thermal diffusivity between -180 and 300°C. The crystallographic textures of the materials were represented by pole figures.     

Getting to X

Just as there exist many forces driving the need for change on many fronts in health care, there are corresponding forces, some equally strong, that resist the change. The article presents a model for nurse executives to help them understand the predominant forces of change. The article also emphasizes the importance of organizational politics in the change process.     

Understanding Generation X employees

Understanding Generation X employees--those born between 1961 and 1981--is essential if they are to be recruited into and retained in nursing and their potential maximized. The author discusses the times, characteristics, and work values and demands of Generation X. Armed with an enhanced understanding, nurse administrators are better prepared to maximize the potential of Generation X employees.     

Fragile X syndrome.

This article provides an overview of current research on Fragile X Syndrome, and how that knowledge can be used to guide successful intervention. The genetic etiology of Fragile X is reviewed and the physical, cognitive, adaptive, behavioral, and emotional phenotypes of children with the disorder are described, highlighting the differences in presentation among males and females. Comorbidity with autism is addressed. Typical strengths and weaknesses of children with Fragile X are delineated as a basis for educational assessment and intervention. A multidisciplinary approach to treatment is advocated, including medical management, educational accommodations, and speech-language and occupational therapy. The social and emotional challenges of those with the syndrome are considered in recommended interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The fragile X syndrome

The aim of this study was to investigate the role of nitric oxide in metabolic disturbances induced in brain tissue of fetal guinea pigs by oxygen-glucose deprivation. Experiments were performed on hippocampal slices so as to exclude the effects of nitric oxide on the cardiovascular system. Metabolic disturbances were assessed by measuring changes in energy metabolism and protein synthesis after different periods of oxygen-glucose deprivation (OGD). Ten min after OGD of 40 min duration, the concentration of cGMP in tissue slices rose from 1.35 +/- 0.38 to 18.6 +/- 1.04 pmol/mg protein (P < 0.05). This rise was almost completely inhibited by the addition of 100 microM N-nitro-L-arginine (NNLA), indicating that NO-synthase was strongly activated after OGD in fetal brain tissue. However, addition of NNLA improved neither protein synthesis nor energy metabolism measured 12 h after OGD. Thus, nitric oxide does not appear to contribute directly to processes leading to metabolic disturbances induced by transient ischemia in immature brain tissue.     

Steel cleanness requirements for X65 to X80 electric resistance welded linepipe steels

Abstract

In Australia, a large proportion of the gas pipelines traverse rural areas of low population density with considerable distances between population centres. As these pipelines transport non-sour gas, there have been considerable economic advantages to be gained from the use of thin walled, small diameter, high strength linepipe grades. The successful development of these X65 to X80 grades has required a balance to be constantly maintained between process parameters, alloy design constraints and quality control measures. This paper considers this mixture of metallurgical and processing challenges in the context of steel cleanness. The steelmaking and casting processes are required to not only produce a low volume fraction of suitably morphology modified inclusions, but also to ensure their dispersion in cast and hot rolled structures. Critical in the achievement of these aims was found to be the order in which calcium treatment and vacuum processing of the liquid steel are carried out. As these steels are complex microalloyed grades, the clean steel concept was extended to include the composition and precipitation of the carbide and nitride species. This broad approach to steel cleanness was achieved while also maintaining a narrow range of casting temperature and chemical composition.     

Characterization of X80 and X100 Microalloyed Pipeline Steel Using Quantitative X-ray Diffraction

Quantitative X-ray diffraction characterization of four (4) X80 and three (3) X100 microalloyed steels was undertaken. The effect of through-thickness position, processing parameters, and composition on the measured crystallite size, microstrain, and J index (relative magnitude of crystallographic texture) was determined. Microstructure analysis using optical microscopy, scanning electron microscopy, transmission electron microscopy, and electron-backscattered diffraction was also undertaken. The measured value of microstrain increased with increasing alloy content and decreasing cooling interrupt temperature. Microstructural features corresponding to crystallite size in the X80 steels were both above and below the detection limit for quantitative X-ray diffraction. The X100 steels consistently exhibited microstructure features below the crystallite size detection limit. The yield stress of each steel increased with increasing microstrain. The increase in microstrain from X80 to X100 is also associated with a change in microstructure from predominantly polygonal ferrite to bainitic ferrite.