Rusting behavior and preventative measures of hot-rolled steel plates for automobile applications

As one of the important categories of hot-rolled products, hot-rolled steel plates for automobile applications generally undergo uniform corrosion or localized corrosion according to different environments of manufacturing, transportation and/or storage of the plates. General corrosion often takes place on the surface of a plate in the exterior part of a package, and only reduces the thickness of the plate and slightly increases the roughness of the surface; however, localized corrosion on the surface of a plate inside the package is likely to result in the formation of pit-like defects on the substrate of the plate, which cannot be removed thoroughly by normal acid pickling or sand blasting, and affects the application of the plate. This research report analyzes the phenomena and characteristics of the rusting behavior of hot- rolled steel plates for automobile applications, and the influencing factors are summaried. The corresponding preventative measures are proposed.

Patenting of hot-rolled high-carbon steel and its applications

The patenting process of three hot-rolled steels with carbon mass contents of 0.70%-0. 90% was studied. The effect of the quenching temperature on the cementite lamellar distance in the steel was evaluated on the basis of microstructural characterization and mechanical property tests. The patenting treatment of high-carbon hot- rolled strip and its application in springs were discussed.

Development of accumulative roll bonding for metallic composite material preparation and mechanical/functional applications

Accumulative roll bonding(ARB)is a severe plastic deformation method to prepare the metallic composite material by physical method at room to elevate temperature,without the generation of additional waste solid or gas.With the physical characteristicsmulti-material and hybrid structure,the mechanical and function properties of the ARB composite material,like Al/steel,Al/Mg,Al/Cu,etc.,shall have the"1+1>2"effect on the mechanical and functional properties,including the remarkable properties that include lightweight,high strength,thermal/electrical conductivity,electromagnetic shielding,and other functions.To deeply investigate the preparation method and microstructural evolution of various metal laminates by ARB,as well as the mechanical and functional properties of the laminate,an overview of the history of ARB technique,the breakthrough of ARB sheet properties,as well as the relative products in industries is provided.Addi-tionally,the future development of ARB technology and the utilization of composite materials in different areas will be discussed.

Research and application of the angular rolling technology for plate mill

Angular rolling technology can overcome the size limitation of plate mill equipment and product heavy steel plate with large unit weight or improve the production efficiency of small width spreading ratio product.With the DEFORM software,the numerical simulation study of the angular rolling process was carried out,and the relation laws of the width,rolling force and strain of the rolled piece under different angular rolling process conditions were obtained.The simulation results show that with the rotation angle increasing,the width of the rolled piece increases.Comparing with the conventional rolling process,the rolling force changes gradually during the biting and throwing stage of the angular rolling pass.With the rotation angle increasing,both the equivalent strains in the thickness direction and in the width direction gradually increase.According to the pattern and dimension's changing formula in the double-pass angular rolling process,the prediction model of angle,reduction and width spreading is built.The opening value of side guide is set for the rotation angle controlling.For one 5000 mm heavy plate mill,the automation control system was modified,and the angular rolling technology was applied online.The absolute deviation of target width does not exceed±20 mm and the relative deviation does not exceed 1%.The large unit weight plate that cannot be rolled with traditional process,can be produced now,and the annual output increases by 10000 t.

Stress distribution and fatigue life of built-up sleeved backup roll

The advantage of built-up sleeved backup roll was described. Based on the stress distribution analysis and simulation for the built-up sleeved backup roll by using finite element method, the effects of roll sleeve thickness and shrink range on the stress-strain field were studied. Finally, based on the methodology and strategy of the fatigue analysis, fatigue life of backup roll was estimated by using the stress-strain data obtained through finite element simulation. The results show that roll sleeve thickness and shrink range have a great influence on sleeve stress distribution of built-up sleeved roll. Under the circumstance of ensuring transferring enough torque, the shrink range should be kept small. However, thicker roll sleeve has longer roll service life when the shrink range is constant.

Manufacturing Technology and Application Trends of Titanium Clad Steel Plates

Some of the major manufacturing processes and corresponding mechanical properties of titanium clad steel plates were analyzed, and the consequences of research, manufacturing, and application of titanium clad steel plates in both markets of China and overseas were also summarized. As an economical and environmentally friendly technology, the roll bonding process is expected to become the next-generation mainstream process for the manufacturing of titanium clad steel plate. Some of the crucial and most important technical problems of this particular process, including vacuum sealing technology, surface treatment process technology, application of a transition layer, and rolling process, were discussed along with the advantageous mechanical properties and life-cycle economy of these plates processed by this technology. Finally, the market needs, application trends, and requirements of titanium clad steel plate were also considered from industries of petrochemical, shipbuilding, marine, and electric power.

Texture evaluation in AZ31/AZ31 multilayer and AZ31/AA5068 laminar composite during accumulative roll bonding

This article presents the texture development of magnesium AZ31 alloy in the accumulative roll bonded(ARB) AZ31/AZ31 multilayer and AZ31/AA5086 laminate composite.The comparative study demonstrates that the texture evolution in AZ31 in a multilayer system is strongly influenced by the interfaces.A typical basal texture of AZ31 has been observed in AZ31/AZ31 multilayer with texture intensity increased with the rolling deformation.Presence of AZ31/AA5086 interface in the laminate composite leads to a tilted basal texture along the rolling direction(RD) in AZ31 alloy.The texture intensity of composite increased initially with rolling reduction and weakened at the higher rolling strain.Weakening of texture in AZ31 during the laminate processing at higher strain has been attributed to the development of wavy interfaces in AZ31/AA5086 laminate.

Rolle定理证明及应用的探讨

对Rolle定理的两种不同证明方法,即闭区间套定理、最大值与最小值定理证明进行了深入的探讨,并对定理的推广及应用作了进一步的分析研究。

Optimization technology of scheduling for hot-rolling mill

To establish the rolling plan of cold-rolling flattening set is very complicated,it is restrained by several constraints of rolling schedule.Operator's subjective and other human factors also affect the rationality of plan arrangement seriously.Its result causes many abuses such as overusing transition strip,high-frequent roller switching,no-fully utilization of rollers,low arrangement rate of the plan.Therefore,we have initially developed a practical optimization model of rolling plan and schedule,which could be established and optimized by computer automatically,and a dynamic alignment module which have friendly UI according to the experience of operators.They have greatly enhanced the system usability.This system takes full advantage of relationship between the roller roughness and the rolling weight,reasonably arranges rolling based on different roughness demand,effectively enhances the use factor of roller and the smooth quality of steel string coil. A practical and effective scheduling optimization algorithm and rolling scheduling optimization applications system was developed based on the study of mixed hot rolling scheduling optimization model of carbon steel,stainless steel,stainless steel and carbon steel cross-rolling.The online application indicates that the model and algorithm is designed reasonable,practical and effective.This model system can significantly improve the scheduling efficiency and quality and it's also very positive in reducing heating energy consumption,enhancing the volume of units rolling plan,and optimizing the production of hot-rolled unit organization and planning and scheduling.

Rolle中值定理的推广及其在解题方面的应用

微分中值定理把函数在区间上的值的变化与导数联系起来,是利用导数研究函数整体性状最基本的理论依据,在数学中十分重要,内容极为丰富。以Rolle中值定理为例,把一元函数的Rolle中值定理推广到多元函数及向量值函数的情形,并进行了几何分析,最后通过实例阐述了Rolle中值定理在解题方面的应用。

Rolle定理及应用举例

给出了Rolle定理构造性的证明,寻求到了结论中c值的实际计算途径。对定理在证明中的应用作了较深入的探讨。

Recent progress in the research on magnesium and magnesium alloy foils:A short review

Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation coefficients,magnetic and electrical conductivities,as well as high theoretical specific capacity.However,magnesium alloys exhibit poor deformation ability due to their hexagonal close-packed crystal structure.Preparing magnesium and magnesium alloy foils with thicknesses of less than 0.1 mm is difficult because of surface oxidation and grain growth at high temperatures or severe anisotropy after cold rolling that leads to cracks.Numerous methods have been applied to prepare magnesium alloy foils.They include warm rolling,cold rolling,accumulative roll bonding,electric plastic rolling,and on-line heating rolling.Defects of magnesium and magnesium alloy foils during preparation,such as edge cracks and breakage,are important factors for consideration.Herein,the current status of the research on magnesium and magnesium alloy foils is summarized from the aspects of foil preparation,defect control,performance characterization,and application prospects.The advantages and disadvantages of different preparation methods and defect(edge cracks and breakage)mechanisms in the preparation of foils are identified.

宽板连轧锥形工作辊轴向窜动调控及工业应用

为了提高连轧锥形工作辊轴向窜动控制精度,对材料加工时发生横向流动的过程建立有限元模型,并构建了机架轧后屈服模型,并将模型置于现场环境中开展验证研究。研究结果表明:受到轧后屈服作用时,处于边降区(15~115)mm之间的断面误差可以控制到3μm范围内,与带钢边部的最大偏差在(0~15)mm之间。在机架间和轧制区内都出现了横向流动的情况,导致锥形辊发生了边降调控性能下降。随着窜辊量增大后,第一、二机架都出现功效下降的结果,第三机架则持续增大至最高功效。下游机架窜辊位都位于上游机架控制特征点范围内。这里调控方式形成了显著边部效果,可以观察到内部偏差。该研究对保证板材的轧制质量具有很好的实际指导价值。

硅钢退火炉高温钢丝炉辊的研究及实践

介绍了一种用于无取向硅钢退火炉的高温钢丝炉辊,新型钢丝炉辊表面无结瘤,无异常磨损,上线使用后能够替代传统炉底碳套辊,减少开炉检修次数,有效提升生产线作业效率。

辊压连续成型制备聚丙烯超疏水表面

在平板热压印技术的基础上优化了工艺,以不锈钢筛网作为模具,通过控制变量法,采用热辊压压印的方式,以聚丙烯(PP)薄膜为基材,并使用具有疏水性的二氧化硅(SiO_(2))微球进行修饰,最终制备出了具有超疏水表面的薄膜,并对样品的耐久性进行了测试。实验总结出了合适的辊压工艺参数:辊压温度为170℃,辊压压力为10 MPa,辊轮转速为2.0~2.2 r/min。结果表明,该方法可以在PP薄膜表面连续构筑出具有较好疏水效果的二级复合微纳结构,并且,表面镶嵌的SiO_(2)微球使薄膜耐久性显著提高,接触角为154°,滚动角为1°。文章优化了热压工艺,即采用了热辊压印的方式,采用SiO_(2)疏水微球修饰薄膜表面,显著增强了薄膜表面的耐久性和力学稳定性。

基于压电原理的装配式结构套筒灌浆饱满度检测方法研究

为解决当前装配式结构套筒灌浆饱满度检测成本高、难以实时检测的技术难点,开发了基于压电测试原理的检测方法及设备,开展了相关的材料试验、模型测试和工程应用研究。首先,通过灌浆料的电学特性测试,探究灌浆料类型和凝固时间对压电测试结果的影响;然后,通过透明套筒的灌浆-漏浆循环试验,分析压电法对漏浆缺陷测试的有效性;进一步,通过预制模型试验,确定压电法判定灌浆饱满度的阈值;最后,依托广州东晓南路—广州南站连接线装配式桥梁工程,验证了压电法用于测试灌浆饱满度的有效性和实用性。研究结果表明:在埋没于灌浆料后,压电传感器测得的谐振电压显著降低,且该电压值在60 min内总体保持平稳,之后随着凝固时间的增加,电压值增长,且逐渐接近试验前初始电压值。在灌浆-漏浆循环试验中,无论传感器采用平放还是竖放的埋设方式,谐振电压均呈现出较明显的变化,说明压电法受传感器埋设方式的影响较小。对于套筒内灌浆饱满情况,其测量电压与灌浆前初始电压之比小于0.4,此数值可作为灌浆饱满度的判定阈值。工程应用结果表明,压电法现场操作方便,可指导现场对灌浆缺陷套筒进行补浆,满足对装配式结构套筒灌浆过程中的质量控制要求。研究结果为解决套筒灌浆质量检测难题提供了一种新途径和实践参考。

不同盾构接收技术在地铁施工中的应用分析

盾构接收作为盾构施工过程中的关键风险环节,其技术选择对工程安全与经济效益具有显著影响。基于南京地铁三个车站的盾构接收案例,对比分析了传统“现浇混凝土挡墙”工法、“钢套筒”工法以及新兴的“装配式钢板箱”工法。通过适用条件、安全性能、施工工效、施工成本四个维度的综合评估,研究发现“装配式钢板箱”技术在盾构水中接收环节展现出显著的应用优势,特别是在应急抢险场景下的应用潜力,旨在为类似工程条件下的盾构接收技术选择提供理论依据。

基于PLC的万能轧制在邯钢重轨轧制生产中的应用

邯钢大型型钢生产线采用万能轧制的方法,可生产各种规格的型钢及高精度重型钢轨。该生产线采用PLC自动控制技术,重点对万能轧制法的相关技术进行详细阐述,并探讨了万能轧制法在邯钢重轨轧制生产中的应用效果。基于PLC的万能轧制工艺的应用,实现了对重轨轧制过程的高度自动化及对轧制力的准确控制,保证了重轨产品的质量。

EN 50155:2021标准中的型式试验的技术要点解析

本文对EN 50155:2021中的型式试验要求进行了解读,概述了各试验项目的要求,总结了按标准开展型式试验过程中的注意事项,为业主、设备供应商和第三方检测机构的相关人员在开展型式试验时提供必要的技术参考。

自动化控制技术在轧钢生产过程中的应用分析

文章先对轧钢生产过程中常用的自动化控制技术进行了分析,并结合轧钢生产过程进一步研究了轧钢设备监控、轧钢生产参数、控制轧钢生产质量检测和轧钢生产安全管理中自动化控制技术的具体应用,充分肯定了自动化控制技术在轧钢生产中的重要性。通过对自动化控制技术的合理运用全面促进了轧钢生产效率、质量和安全管理成效的提升,加快了轧钢企业的现代化发展进程。