30Mn水淬钢调质热处理工艺的研究

测定了30Mn钢的CCT曲线和淬透性。研究表明,当冷却速度大于60℃/s时,能得到50%以上的马氏体组织,淬透性能满足Φ245mm×13.84mm以下油井管的要求。在此基础上研究了不同的回火温度、回火保温时间、淬火温度和淬火保温时间对30Mn钢组织性能的影响规律,制订了实验室条件下的调质热处理工艺,并进行了试验研究。结果表明,经此调质工艺处理后,材料的力学性能达到了API5CT标准要求。作为水淬钢种,30Mn钢可用来生产N80Q钢级的油井管。     

宝钢股份油井管水淬热处理系统

文章介绍了宝钢股份研发的油井管水淬热处理装置特点、主要功能及经水淬热处理后的产品性能。研究表明，宝钢开发的钢管水淬设备可以高效、批量生产高质量油井管。     

宝钢油井管水淬技术的开发研究

介绍了宝钢油井管水淬热处理技术的开发情况。其中重点介绍了水淬工艺及经水淬后钢管的平直度、硬度均匀性和机械性能。研究表明,宝钢油井管经水淬热处理后的内在质量达到世界先进水平。     

油井管内喷旋流淬火设备与技术的开发

为获得理想的力学性能,大部分的油井管在制造过程中都需要采用淬火＋高温回火调质处理。在简要介绍钢管淬火技术和设备现状的基础上,重点介绍了一种新型的油井管内喷旋流淬火技术的原理、特点和设备组成．并通过实际运用证明了该内喷旋流淬火设备具有结构简单、淬火冷却均匀、运行维护费用低等特点,该项技术运用于油井管的淬火处理能够获得较高的淬火质量。     

高钢级油井管淬火装备的研发与应用

针对油井管整体淬火后容易弯曲和缺少能满足快速通断要求的三通阀等装备研发中的技术难点,根据高钢级油井管淬火装备的总体技术要求,设计开发了旋转式内外喷淋淬火装备,并实现了工业应用。     

新型淬火介质的应用

采用新型JEF-G35淬火介质对轴承钢进行淬火冷却的实验,结果表明,采用JEF-G35淬火剂处理的轴承钢,其变形开裂倾向、淬火硬度都优于水淬和油淬,用JEF-G35代替水、油淬火是可行的,有效地解决了油淬不硬、水淬易裂的难题。     

循环加热和淬火对20MnCrNiMo钢组织及性能的影响

对从40 mm厚板坯上切取尺寸为20 mm×40 mm×200 mm的20MnCrNiMo钢试样,分别进行了860℃水淬,860℃水淬再860℃水淬二次淬火,900℃水淬再860℃水淬二次淬火,以及900℃水淬、860℃水淬再860℃水淬三次淬火。经1~3次淬火的试样均于620℃回火。随后,采用光学显微镜、扫描电镜等设备研究了试样的显微组织、断口形貌和力学性能。结果表明,多次淬火可细化钢的晶粒,改善钢的力学性能;三次淬火对组织细化及性能改善的效果好于两次淬火;对于这种钢的两次淬火工艺,初次淬火温度为860℃的工艺能使钢的晶粒更细小,力学性能更优。     

42CrMo钢激光-感应复合淬火淬硬层几何特征及组织研究

采用激光-感应复合淬火的新工艺,将激光和电磁感应两种热源复合提高42CrMo钢激光淬火的淬硬层深度和均匀性。利用COMSOL Multiphysics 5.5软件对42CrMo复合淬火过程中温度场的演变过程进行分析,通过淬火实验对模型进行了验证,淬硬层深度模拟值与实验值一致性较高。采用该模型,比较了复合淬火与单一激光和单一感应淬火在同工艺下淬硬层的表面温度和深度,分析了不同扫描速度和激光光斑尺寸对淬硬层深度的影响。通过实验对复合淬火的淬硬层深度、硬度、晶粒大小和显微组织进行分析。结果表明,激光-感应复合淬火可以有效提高试样的表面淬火温度,提高淬硬层宽度和深度,弥补单一激光淬火功率不足的缺点,通过模型预测了复合淬火最优扫描速度和光斑尺寸。相较于两种单一淬火,复合淬火的晶粒度和显微组织形态在深度方向上的变化趋势与激光淬火相似,且具有更高的淬硬层平均硬度。     

轮毂轴承内法兰盘淬火工艺优化

对55钢轮毂轴承内法兰盘感应加热淬火工艺进行了试验优化,研究了淬火液浓度、电流频率、功率时间比、淬火液流量等因素对淬硬层表面硬度和组织的影响。结果表明,随着淬火液浓度的降低和加热功率的增加,淬硬层表面硬度逐渐升高,在一定范围内,淬火液流量和淬火频率对淬硬层表面硬度影响不显著。淬火液浓度过低会导致淬火开裂风险增加,加热功率升高会导致淬硬层表面马氏体粗大。淬火液浓度5%,加热功率169 kW,加热时间5. 6 s,淬火频率15 kHz,淬火液流量80 L/min为最优工艺参数。     

全自动石油钢管调质生产线

简要介绍了西安重型机械研究所与胜利石油管理局总机械厂开发研制的油井管淬火和回火处理生产线的工艺流程、设备组成及其特点 ,为进一步研制生产调质钢油井管的设备和工艺提供了宝贵的经验     

Pitting corrosion of older underground cast iron pipes

Major water supply distribution networks in many cities consist of buried cast iron pipes. Often the pipes are internally cement-lined. For these the most severe external pitting corrosion is important because this may cause leakage and eventual structural failure. Herein representative data is reported for 10 pipes, ranging in age from 34 to 129 years and from 200 to 600?mm diameter that are part of a larger data set. The pipes examined were selected by the water utilities from several critical locations. Pit depths over 1–2?m lengths of pipes were measured and examined and soil properties measured. The morphologies of pitting around the pipes were found to be very different, with often much greater pit depths and larger pit areas at the base of the pipes. There were also considerable differences along the length of individual parts of pipes. When plotted on a Gumbel plot for the maximum pit depths, the deepest pits showed a different Gumbel trend compared with the majority of pit depth maxima. Theoretically, this indicates that different pitting mechanisms are involved. This possibility is explored by reference to earlier work on the long-term pitting corrosion of steels in sea water. Comments are made also about empirical fitting with other extreme value distributions, as sometimes suggested.     

长期存储对钢管质量的影响及建议

分析了钢管在国内干燥气候地区、年降雨较多地区长期露天存储时存在的问题,并提出了具体解决措施.分析认为：目前国内钢管长期露天存储时,存在表面锈蚀、壁厚与椭圆度超差、防腐层老化及翘边等问题;因此,建议在开始存储时就使用结实耐用的不透明遮盖物,遮盖时保证钢管表面通风,存储时有支撑物,去除管端保护器,确定合理的堆放层数等.     

高压锅炉管用T22钢的热处理研究

国内某大型锅炉公司向扬州龙川钢管有限公司订购的高压锅炉管T22批量大,热处理难度较高,生产中经常出现产品批量性能不合格的情况。主要体现在钢管硬度偏高,显微组织不稳定,晶粒大小不均匀。因此常常需要对产品重新进行热处理,加长了生产周期,降低了生产效率,增加了生产成本。通过对T22钢管进行的一系列热处理试验研究,制定出合理的热处理工艺,使产品的热处理合格率大幅提高。     

Effect of barium on the phosphorus content of deposited metal of welded joints in cold‐resistant steels

The methods of producing two-layer pipelines of different design, including bimetallic pipes, consisting of carbon and high-alloyed stainless steels, are investigated. It is shown that at optimum design, the welded joints in the pipes should be distributed in a zigzag order so that the welded joints on the external and internal pipes are away from each other.     

发动机燃油管断裂故障分析

某型发动机燃油管多次发生断裂故障,断裂部位在管接头端焊缝附近,采用断口分析、金相组织分析、管道强度计算、安装应力测量等方法,对燃油管断裂的原因进行了分析。结果表明,燃油管安装应力过大是引起断裂的主要原因。结合实际经验,加强装配过程控制,提高装配质量,可有效预防燃油管断裂故障。     

Influence of Pipe Quality on corrosion of galvanized steel pipes for domestic water supply

Experiments were made for the purpose of comparing corrosion in galvanized pipes of eight different makes in hot and cold domestic water. Fittings of two makes and two methods of jointing were also compared. Experiments were made throughout a period of 15 months under conditions closely simulating conditions in practice. The water used was relatively hard with fairly high salt content and had in practice caused pitting corrosion in galvanized pipes. The experiments confirmed that corrosion of pipes is only to a slight extent influenced by the pipe quality. The only exception was galvanized pipes with a thin coating and with no layer of pure zinc. These pipes seemed clearly to be less resistant. The experiments disclosed no difference between the two types of fittings or between the two jointing methods. Pipes in which hot water circulated continuously showed on the whole more corrosion than pipes with cold water or with hot water without circulation. However, the most serious case of pitting corrosion was observed in a cold water pipe. In connection with the experiments lead and cadmium were determined in the zinc coatings from the pipes and in water samples from the experimental set-up. Contents of zinc and copper in the water samples were also determined.     

优化焊管结构增加高附加值产品

简析了80年代以来国内钢管的消费结构 ,指出近年来焊管的消费量已经大于无缝钢管 ,焊管业应抓住这一契机 ,根据产品的市场需求 ,拓展服务领域 ,优化焊管内部结构 ,发展走向空间 ,推进锅炉管、油井管、远距离输气输油管线管、低合金高强度结构管、涂层管、冷加工管和不锈钢管等焊管品种的生产。     

Development of steels and heat treatment modes for cold-resistant and hydrosulfide-resistant high-strength pipes

The structure and mechanical properties of pipes from steel 26KhMFA after hardening and tempering at various temperatures are considered. The possibilities of ensuring mechanical properties in pipes of strength group E and higher are considered. The highest strength categories attainable by heat treatment are determined for each composition. Effective compositions and modes of heat treatment are recommended for the production of hydrosulfide-resistant pipes. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 18–22, May, 2007.     

蛇形管管排焊接的难点与对策

大型散装热水锅炉的省煤器系统内部结构采用了密布蛇形管排布置形式,管间位置狭窄、管排密集。蛇形管间障碍焊是焊接这种结构的难点。通过分析蛇形管管排空间位置特点,经过多次模拟试焊,确定采用钨极氩弧焊,并改造了氩弧焊枪,制定了特殊位置焊缝的焊接工艺,同时对常见的焊接缺陷提出了解决措施,形成了一套比较成熟的焊接工艺。在实际工程中,采用此工艺进行焊接,焊缝一次合格率达到了98.7%。施工进度也由以往一天焊20余道焊口,提高到一天焊60余道焊口。     

高温高压管道焊接坡口选择及焊条用量计算

从经济和技术角度分析火电厂高温高压管道焊缝宜采用的坡口形式,并对各种坡口形式的焊条用量估算推导出经验公式.