新一代TMCP的实践和工业应用举例

介绍以超快速冷却为核心的新一代TMCP技术在钢材生产中的广泛应用和由此而导致的钢材性能的提升.这些应用包括棒线材控轧控冷技术突破和应用、轴承钢的轧后超快速冷却控制碳化物分布、利用超快速冷却技术进行热轧带钢组织复相化控制,以及热轧带钢轧机实施超快速冷却装置的改造和中厚板轧机实施超快速压力喷射式冷却 ACC的新式冷却系统的建立.     

再结晶控制轧制在高强度压力容器钢板研制中的应用

为了提高产品的性能,本试验对容器钢的化学成分进行了优化,并采用RCR(再结晶控制轧制)+ACC(加速冷却控制)工艺对250 mm厚的连铸坯轧制到30 mm厚,轧后进行了正火处理。通过对热轧板和正火板进行金相检验和力学性能测试,分析了轧制工艺与钢板组织和性能的关系。试验结果表明,采用RCR+ACC工艺生产的钢板正火后各项性能均满足技术要求。与常规工艺相比,RCR+ACC工艺生产的正火板组织分布更均匀,-40℃横向冲击功达到154 J,实现了组织和性能的良好匹配。     

中厚板轧后控制冷却系统

介绍了轧后控冷技术的发展及其作用,指出通过应用轧后控冷技术,可以细化钢板晶粒,提高钢板的强度,代替正火工艺;分析了轧后控冷工艺主要工艺参数如冷却速度、水量及返红温度的控制对于控制冷却系统的影响;对实现轧后控冷技术关键部分的控冷设备及其自动化控制系统的主要构成及特点进行了详细介绍,并对中厚板轧后控冷技术的未来发展趋势进行了展望。     

中厚板轧后控冷系统及其应用

介绍了武汉钢铁（集团）公司轧板厂轧后控冷系统的工艺布置、冷却设备、技术特点及其使用效果，这套控冷系统冷却范围宽、冷却均匀性好，对中厚板性能的改善较明显。     

控轧控冷工艺对低碳贝氏体钢组织性能的影响

通过在中厚板轧机上进行的控轧控冷工艺试验，研究了不同控轧控冷条件对低碳贝氏体钢DB685组织和性能的影响，得出增大变形量可得到细小均匀的晶粒组织，使钢材的强韧性提高；增大轧后冷却速度能有效地提高钢板强度。并提出了工业生产DB685钢的控轧控冷工艺参数：终轧温度≤850℃，轧后冷却速度≥5℃／s，终冷温度≤650℃。     

中厚板轧后超快速冷却控制系统的开发与应用

以中厚板轧后超快速冷却控制系统为对象,分析了系统内部以及与外部系统的通讯方式,建立了基于样本微跟踪策略的功能控制和数学模型,并结合中厚板生产过程的特点进行优化和创新.采用超快速冷却系统进行轧后控制冷却后,简化了系统的调试和维护过程,满足了过程控制系统准确性和稳定性的要求,最终实现了产品工艺参数高精度控制.     

运用控轧控冷工艺提高钢板力学性能

结合马钢中板生产实际, 对控轧控冷工艺中快速轧制, 快速冷却, 大压下量开坯, 大压下率终轧及碳当量对温度控制的影响等主要方面进行了探讨, 并得出适当的工艺参数, 从而大大提高了钢板力学性能合格率。     

简析控轧控冷技术在无缝钢管生产中的应用

从在线常化工艺、在线淬火工艺和在线快速冷却工艺等3方面介绍了控轧控冷技术在国内无缝钢管生产中的应用情况;分析了控轧控冷技术在无缝钢管生产中应用有待加强的问题。分析讨论认为:目前需加强P110钢级油井管、高钢级管线管及高压锅炉管的在线热处理试验研究;完善检测手段和控轧控冷装置;根据机组的类型,选择适宜的控轧控冷工艺等。     

控轧控冷技术的发展及在钢管轧制中应用的设想

传统控轧控冷(TMCP)技术由于受到冷却能力的限制,对钢材性能的提高有一定局限性.为了进一步强化钢材的性能,提出了以超快速冷却技术为核心的新一代控轧控冷(NG-TMCP)技术.该技术提高了钢的细晶强化、析出强化、相变强化等多种强化机制,充分挖掘了钢材的潜力.介绍了NG-TMCP技术目前在热轧带钢、中厚板、棒线材及H型钢...     

25MnV钢贝氏体转变行为研究

通过膨胀仪方法,研究了25MnV钢在模拟2种无缝钢管控轧控冷试验工艺条件下的贝氏体转变行为。结果表明,在终轧温度较高,轧后快速冷却到390～485℃再缓冷的情况下,可获得硬度大于22HRC的全贝氏体组织。采用控轧控冷工艺生产贝氏体组织N80钢级套管是可行的,此项研究成果为开发贝氏体非调质热处理钢管提供了依据。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

FORMULAS OF TENSION OF CONTINUOUS ROLLING PROCESS

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.     

RHEOLOGY FEATURE OF SIMPLE METAL MELT

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.