钢板弯曲试验后出现裂纹的原因

通过对SS400钢板的一系列分析，得出了造成SS400钢板冷弯试验后出现裂纹的原因，即主要是钢板表面附近具有一定大小的硅酸盐夹杂物所致。     

SS400B含硼钢热轧卷板表面翘皮缺陷的改善

对SS400B加硼钢热轧卷板表面翘皮缺陷特征进行了分析。研究结果表明,连铸坯角部横裂纹是导致SS400B钢热轧卷板产生表面翘皮缺陷的主要根源。通过采取钢种成分的调整,优化连铸二冷制度,减小结晶器锥度等措施,消除了SS400B钢卷板表面翘皮缺陷,热轧卷板合格率达到100%。     

SS400热轧酸洗钢高频电阻焊焊缝微裂口原因分析

某厂使用SS400热轧酸洗钢板生产压缩机主壳体,在检查高频电阻焊管焊缝时发现微裂口缺陷。取缺陷样和未加工原板分析,主要包括宏观分析、成分分析、力学性能检测、金相分析、扫描电镜及能谱分析。结果表明,SS400钢的成分中锰含量高,焊接时产生的MnO不易被完全挤出,导致焊缝微裂口缺陷。通过调整该钢的成分,提碳降锰,解决了焊接裂口问题。     

不同退火工艺下建筑抗震钢板的显微组织和力学性能研究

研究了不含V和含V的两种抗震钢板在退火温度为790~850℃范围内的显微组织和力学性能。结果表明,随着退火温度的升高,抗震钢板中贝氏体含量逐渐增多而多边形铁素体晶粒逐渐细化。A2钢板中的贝氏体弥散分布在铁素体基体上,而A1钢板中的贝氏体呈现条带状分布特征。A2钢板退火后析出了纳米级V(C,N)相,该钢经过830℃退火处理后可以获得较好的综合力学性能。     

轧制冷却工艺对LT-FH32低温钢组织及性能的影响

测试了不同控轧控冷工艺参数下LT-FH32钢板的力学性能和显微组织,研究了控轧控冷工艺参数对低温钢LT-FH32组织性能及强化机制的影响。结果表明,减小待温厚度,减少精轧压下量,采用较快的轧制速度,可以降低钢的屈强比。当中间坯待温厚度为1.5 t、4 t(t为成品厚度),终轧和终冷温度分别控制在790℃和560℃,并且轧后水冷速度控制在5～10℃/s时,钢具有较好的综合力学性能。     

TRIP780高强度钢板动态力学特性的研究

通过准静态和动态拉伸实验,获得了材料的力学性能参数,分析了TRIP780高强度钢板材的力学性能特点。基于Johnson-Cook模型建立了描述TRIP780高强度钢应变率相关性的本构关系模型,并将由该模型模拟得到的动态拉伸结果同实验结果进行对比,对比结果表明,数值模拟的结果与实验结果具有较好的一致性。利用数值模拟技术,分别模拟TRIP780钢和普通IF钢的薄壁梁冲击压溃过程,结果表明,TRIP780具有较好的抗冲击碰撞性能。     

焊接结构用厚钢板生产研究与应用

由于厚规格焊接结构用钢板受大压缩比以及厚度方向性能的限制,产品合格率低,生产难度大。采用TMCP+正火的工艺成功研制了厚规格焊接结构用Q345EZ35钢板。对正火态钢板的组织和力学性能进行了检测,结果表明试制钢板力学性能满足标准要求。     

SS400厚规格带钢力学性能的控制

在研究分析SS400带钢热变形中组织演变规律的基础上,通过优化控制轧制控制冷却工艺,并采取提高温度检测的准确性和加强层流冷却系统的维护等措施,较好地解决了唐钢1810mm生产线生产的SS400厚规格带钢的力学性能偏低问题.     

1000MPa级DP钢的成形特性试验

对宝钢产1000MPa级冷轧双相钢和热镀锌双相钢的材料特性和成形特性进行试验,深入分析钢板的力学性能、扩孔性能和成形极限。研究表明,宝钢1000MPa级超高强钢板具有较好的力学性能,其延伸率和扩孔率与国外同类产品相近,成形极限试验测量得到的FLD0为18%,低于采用软钢经验公式计算值。摩擦试验表明,冷轧GI板表面摩擦系数明显低于热镀锌CR板,此外,涂油对CR板表面影响较小,但对GI板表面有较大的影响。     

热处理温度对超高强海工钢组织性能的影响

针对超高强海工钢的研发，采用低碳和较高Ni含量设计了实验钢化学成分，通过力学性能分析及显微组织观察，对比研究了热轧钢板、以及不同热处理温度实验钢板的组织性能，明确了不同热处理温度对超高强海工钢板力学性能的影响规律。结果表明：热轧钢板组织基本为全马氏体组织，经热处理后开始析出碳化物，在热处理温度为650℃时界面处存在一定量的新鲜马氏体或残余奥氏体；经400、500、600℃热处理后，虽然可将实验钢板屈服强度提高至1 000 MPa以上，且断后伸长率大于14%,但由于存在时效脆性，使得钢板在-80℃时发生脆性断裂。经650℃热处理后，尽管实验钢板的屈服强度下降，但仍保持超高屈服强度，为786 MPa;另外，实验钢板的低温冲击韧性得到了显著改善，-80℃冲击吸收功大于125 J,具有最佳的综合力学性能。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

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.