温轧机的轧辊加热方式研究

温轧机轧辊加热通常有电热丝及感应加热两种方式.通过对比两种加热方式在辊面温度上升的速度和有效轧制辊面区域温度分布均匀性两方面性能,发现感应加热装置可使轧辊表面快速到达目标设定温度,加热效率高,轧机工况更安全.此外通过加装辊面气道吹扫装置可有效调节辊面轴向的温度均匀性,使温轧机的有效轧制区间扩大.     

第四届国际轧钢会议

第四届国际轧钢会议于1987年6月1～3日在法国Deauville召开,这次会议的主题是板带轧制的理论与技术。来自38个国家和地区的700多名代表参加了这次会议,会上共宣读了150篇学术论文。我国共有7名代表参加了会议(包括台湾省2名),在会上宣读了8篇论文(包括台湾省2篇)。这次会议论文的内容总的概括起来涉及以下几个方面:热带轧制、冷带轧制、中厚板轧制、轧制     

基于数据挖掘的带钢冷轧机轧辊热凸度的研究

在带钢冷轧中,轧辊的热凸度变化会影响厚差及板形质量。然而轧辊热凸度通常难以在线检测。通过建立横向厚差方程,进行热凸度溯源分析,可以找出隐藏在现场数据背后的辊系热凸度变化规律,并在此基础上进行辊系热凸度的在线预报和补偿。将此方法应用在300实验冷带轧机上,并与常规无补偿轧制进行了对比。实验结果表明,辊系热凸度预报可靠,在线补偿对横向厚差具有明显稳定效果。     

提高辊套使用寿命的有效途径

介绍了铝连续铸轧机铸轧辊套的破坏形式,着重分析了辊套的装配应力、轧制应力、热应力等因素对辊套使用寿命的影响.基于ANSYS有限元软件,对辊套进行热结构耦合分析.得到辊套的应力场分布情况.并讨论了辊套疲劳失效的原因,提出了几种提高辊套使用寿命的有效途径.     

高凸度工作辊在炉卷热轧机上的应用

为了适应连铸板坯热装炉和直接轧制的要求,按规格需要轧制不同宽度、厚度和不同钢种的板带材,日本日立制作所在炉卷带钢热轧机上采用了可侧向移动的工作辊,实现了高凸度轧制。这种高凸度轧机具有工作辊弯曲和侧移机构,根据轧制目的有三种控制方法:周期性侧移(CS)法、带钢凸度控制(HC)法和轧辊单侧锥形的位置调节(TA)法。CS 法:于轧制不同宽度带钢时上下工作辊对称移动约20mm,以保证均匀磨损和热凸度,避免因轧辊表面局部磨损而产生辊面的凸出或     

不对称异径五辊轧机冷轧带钢轧制负荷的研究

本文通过试验研究和理论分析得出:(1)不对称轧制时由于一个工作辊直径的减小即可收到显著降低轧制压力的效果。压力下降的原因主要是金属与轧辊接触面积的减小,以及由于小工作辊的大(超)咬入角轧制,促使应力状态减弱而降低了单位轧制压力(甚至比自然抗力K还要小);(2)推导出异径轧制时轧制压力的计算公式,计算结果与实测值基本相符;(3)异径五辊轧机轧制薄带时两辊速度差((v_1-v_2)/v_2)很小(<1％),其影响可以忽略。     

利用激光毛化技术在普通冷带轧机上实现异步轧制

利用激光毛化技术，使两工作辊具有不同的表面粗糙度，以此造成轧制时板带上、下表面摩擦状态的差异，在普通冷带轧机上实现了异步轧制效果。用这种方法实现异步轧制无需改造轧机，工艺简单，成本低廉，生产方便。     

锻钢冷轧辊的使用与维护

用于冷轧薄板的轧辊,常用高碳铬钢、铬钼钢或铬钼钒钢锻造制成,俗称锻钢冷轧辊(以下简称轧辊)。轧辊的工作条件十分恶劣,在轧制过程中,它要承受压应力、弯曲应力、扭转应力、接触疲劳应力和热疲劳应力。为了使轧出的薄板达到规定的尺寸精度和较好的表面粗糙度,要求轧辊辊身表面具有极高的硬度和硬度均匀性。轧辊由于不断地进行轧制作业、表面磨损,形成“桔皮状”缺陷或裂纹,经常需要修磨后再继续使用,     

某热轧1580生产线工作辊热凸度分析研究

热轧精轧机换辊、轧制中断、轧制节奏明显变化等工艺条件下,容易出现较大偏差,导致轧制不稳定、板形有质量缺陷等问题。对首钢某热轧1580生产线工作辊冷却方式进行改造,由辊身均匀冷却方式改为中段集中冷却方式,以便降低工作辊中部温度、减小中部与端部的温差,从而获得较好的工作辊热凸度轮廓曲线,轧制出板形和表面质量良好的带钢产品。     

换辊条件模型的建立与应用优化

<正>柳钢冷轧钢带生产工艺流程为:热轧钢卷→酸洗轧制→退火→平整→切边涂油重卷→包装。为避免酸洗轧制工序中轧辊过钢量过大造成轧辊表面疲劳、剥落、爆辊等问题,须定量换辊。换辊依据有按轧制重量和按轧制长度两种。冷轧厂冷连轧1 250 mm酸轧机组工作辊换辊信息来自冷轧PES系统,1、2、3号机架的换辊模式是按轧制重量,轧制量均为(2 600 t±200) t;4、5号机架工作辊换辊模式是按轧制长度,4号辊轧制量为(180±20) km;5号辊辊轧制量光辊为(100±20) km,毛化辊为     

A thermal elastic-plastic finite-element analysis to roll-life prediction on the twin roll strip continuous casting process

The rolling force and roll deformation behavior in the twin-roll-type strip continuous casting process have been computed to estimate the thermal characteristics of a caster roll. To calculate the rolling force, the relationship between the flow stress and strain for a roll material and a casting alloy are assumed as a function of the strain rate and temperature, because the mechanical properties of casting materials depend on temperature. The three-dimensional (3-D) thermal elastic-plastic analysis of a cooling roll has also been carried out, to obtain roll stress and plastic strain distributions, with the commercial finite-element analysis package of ANSYS. Temperature field data for a caster roll, provided by the authors, were used to estimate the roll deformation. Therfore, numerical models considering the thermal and rolling forces have been developed to estimate the roll life. Roll life considering the thermal cycle is calculated using thermal elastic-plastic analysis results. The roll life is proposed in terms of roll revolution in the caster roll models with and without the fine crack failure on the roll surface. To obtain plastic strain distributions of the caster roll, thermomechanical properties of a roll sleeve with a copper alloy are obtained by a uniaxial tensile test for variation of temperature. The proposed analysis techniques have improved in caster roll design.     

Casting of High-Aluminum-Content Mg Alloys Strip by a Horizontal Twin-Roll Caster

This study was aimed to investigate casting of high-aluminum-content Mg alloys strip by a horizontal twin-roll caster. A horizontal-type twin-roll caster was equipped with a nozzle. This nozzle was movable. The roll size was φ300 × W150, and copper rolls were used. The rolling road was very small. It was possible to cast AZ91D and AZ121 magnesium alloys continuously by a horizontal twin-roll caster. There was gloss and no crack. The thickness of as-cast strip of AZ91D was 4.5 mm and that of AZ121 was 4.6 mm, respectively. In the case that roll velocity was 48 m/min, the thickness of as-cast strip of AZ121 was 2.0 mm. A 2.0-mm-thick strip was able to coil, and the diameter was φ500 mm. The microstructures of the as-cast strip of AZ91D and AZ121 magnesium alloys were observed using light optical microscopy. Isometric dendrite crystals were observed at the as-cast strip. The as-cast strip without facing of AZ91D and AZ121 magnesium alloys were able to hot rolling of 75 pct reduction. The surface of the as-rolled sheet was flat and glossy. The tensile strength of the as rolled was 230 MPa and the elongation of as rolled was 4 pct.     

Tailored Profiles Made of Tailor Rolled Strips by Roll Forming – Part 1 of 2

To fully exploit the potential of sheet and profiles, various technologies to produce tailored blanks and profiles have been developed [1,2]. In earlier work [3] it has been shown that Strip Profile Rolling (SPR) can be used to produce metal strips with a predefined thickness distribution across the width of the strip. Building upon this knowledge, in two subsequent papers the extended goal of the project is presented. Therein is demonstrated that Strip Profile Rolling can be applied very effectively using a combination of roll forming (part 1) as well as further processing by roll forming (see part 2) to allow for the production of profiles with varying wall thickness in their cross section. To achieve the goal of part 1, a numerical model describing SPR was developed and used to study the influencing process parameters on spread and bulge formation. As a result of this parametric study, an optimized roll design and rolling sequence was developed to produce a demonstrator strip on a 12 stand roll forming mill manufactured by the company Dreistern [4]. Starting with a conventional strip out of DC01 steel (width 170 mm, thickness 2.5 mm), 29 rolling passes were necessary to achieve the desired geometry (width 186 mm, thickness 2.5 mm with a longitudinal groove being 64 mm wide where the thickness is reduced to 1.5 mm). In the second part of the process chain the coils produced by Strip Profile Rolling were successfully roll formed into a circular tube of 60 mm.     

非对称轧制对AZ31B镁合金组织及性能的影响

开展了非对称轧制对AZ31B镁合金晶粒细化影响的研究,分析了不同温度及不同压下率时宏观形貌和晶粒尺寸变化,并与对称轧制作了对比。结果表明,非对称轧制的整体晶粒尺寸比对称轧制更为细化;非对称轧制在温度为350 ℃、压下率为60%时晶粒最为细小均匀,上表面、中心层和下表面的平均晶粒尺寸分别为2.35、2.84和2.22 μm。在初轧温度为300～350 ℃范围内,组织产生充分动态再结晶;随着轧制温度继续升高,晶界产生充分迁移和扩散,晶粒随之长大,导致镁合金的综合性能变差。非对称轧制板材的抗拉强度和断后伸长率都优于对称轧制板材,在400 ℃轧制时,压下率为30%时获得较为优异的综合力学性能,抗拉强度为365.36 MPa,断后伸长率为34.9%。     

Influence of mechanical factors on solidification structure of thin strips of Fe–6.5wt-%Si alloy by twin roll casting process

Strips (1.6?mm thick) of Fe–6.5wt-%Si alloy were prepared by twin roll casting. The microstructure was found to be mainly columnar and equiaxed grains. The plastic deformation of the strip is inhomogeneous in the thickness direction. The most serious deformation is located at a certain depth from the strip surface. The influence of mechanical factors on the solidification structure of the strip is discussed. As the two solidifying shells contact with each other at the end of solidification, the columnar growth fronts break into fragments, which finally grow into equiaxed grains. At the hot rolling stage, the inhomogeneous deformation of the strip is attributed to the fact that the ductility of the alloy is sensitive to temperature. There is a large temperature gradient in the thickness direction, which can be up to 510°C?mm^??1.     

热带精轧除尘系统的设计

介绍了宣钢第一轧钢厂热带车间热带精轧过程中烟气除尘系统的方案设计。     

精轧F7机架采用平辊实现自由程序轧制的研究

通过现场实验的方法证明了国内某钢厂2050mm热轧机组精轧F7工作辊由CVC改为平辊，（目的是实施自由程序轧制）单靠现有弯辊能力对板凸度控制的不足，并提出采用大凸度支承辊提高板凸度控制能力的方案。最后采用刚塑性有限元（R.P.FEM）与影响函数法相结合的耦合计算方法分析带钢和轧辊的变形，通过计算给出支承辊的最佳凸度范围。     

带钢热连轧机生产TA10钛合金带的轧制工艺

在带钢热连轧机组上开展TA10钛合金带的轧制工艺优化研究,结合带钢轧制工艺设计,提出多组不同钛带轧制工艺规程,然后直接在带钢热连轧机上进行TA10钛合金带的热连轧生产试验。通过比较研究不同轧制工艺所生产产品的微观组织、力学性能及其他质量状态,揭示了不同热连轧工艺与组织性能的相关性,掌握TA10钛合金带热连轧变形特点,优选确定了TA10钛合金带的轧制工艺及参数,并投入生产应用后使该带钢热连轧机稳定生产出了基本满足相关技术标准要求的TA10钛合金带产品。     

高温轧制对AZ31B镁合金组织和性能的影响

研究了高温轧制工艺对AZ31B镁合金微观组织、织构以及性能的影响规律.在轧制状态下,随着轧制温度从450℃升高至525℃,合金组织内部动态再结晶逐渐增多,孪晶数量不断减少,同时组织的均匀性也得到了改善,基面织构强度也呈下降的趋势.经350℃保温60min退火之后,合金板材内部发生了完全再结晶,孪晶组织消失,显微组织更均...     

精轧变规格辊缝设定不到位问题分析与改进

从宝钢分公司热轧厂2050mm热轧精轧压下组成部分分析出发,结合精轧机械压下和液压压下辊缝设定的原理,同时针对压下辊缝出错的现象,通过分析研究及相关论证找出影响压下辊缝出错的原因,系支撑辊平衡和弯辊力等外力的作用引起压下系统辊缝设定出错,最终通过程序优化解决精轧变规格辊缝设定不到位的问题,解决了由于支撑辊平衡和弯辊力引起的困扰精轧多年的压下辊缝出错故障,提高了精轧辊缝设定的稳定性,保证了正常的生产.