铝包钢丝中频加热的模糊神经网络控制技术

在铝包钢丝生产过程中,采用在线中频感应加热方式。基于中频感应加热条件,针对钢丝直径、钢丝运行速度、加热温度、中频频率、中频电压、中频电流、中频功率、加热炉长度之间的函数关系,建立了连续包覆过程的多变量神经网络控制方法。经过多次实验和筛选,选出有效数据,多个模式反复学习,直至网络全局误差函数E小于预先设定的一个极小值。通过网络训练和仿真分析得到较佳的解决方法,该方法应用在铝包钢丝连续包覆生产线上,较好地解决了钢丝加热控制难的问题。     

铜铝高频感应焊接工艺的探究

运用新型感应加热工艺,通过固-液-固相复合法制备铜/铝复合材料.由于加热功率和加热时间会影响结合层厚度的形成,根据感应加热原理及其焊接过程中焊接速度快、铝融化温度高以及铜铝材料紧密接触等特点,对已有焊接设备进行改进.使用直径为0.1 mm、可耐高温的镍铬-镍硅(NiCr-NiSi)表面瞬态热电偶对铜铝接触面之间的温度进行测量,设计与制造了加热时间控制器及热电偶测温装置,得到在焊接过程中不同感应加热功率条件下加热温度与加热时间之间的工艺曲线,得知铜铝运用感应加热工艺进行焊接时,不同加热功率对应不同的加热时间,感应加热功率越大,加热速率越大,所用加热时间越少;当感应加热功率为12.63kW、加热时间为24s时,所制备的铜铝复合材料结合层效果最佳.     

热轧板坯高温感应加热有限元分析

利用有限元法分析了不同工作频率下的热轧板坯高温感应加热过程,结果表明:工作频率和板坯形状尺寸对感应加热过程有重要影响,工作频率较低时,集肤效应不十分明显,涡流透入深度与工作频率满足δ∝f-1-2关系,温度最大值位于上表面距对称轴一定距离处.随着工作频率增加,温度最大值向板坯角部移动.矩形板坯感应加热过程较为复杂,应根据不同工艺要求选择合适的工作频率.计算了板坯感应加热过程,温度计算结果和实测值吻合良好,计算模型可靠.分析结果为热轧板坯高温感应补偿加热生产实践提供了依据.     

加热功率对感应加热中间包影响的数值模拟

通道式感应加热是实现中间包低过热度浇铸有效方法之一,针对国内某钢厂单流通道式感应加热中间包,建立三维非稳态数学模型,研究通道加热功率对中间包内流场、温度场及夹杂物去除的影响规律。结果表明, 当中间包未受感应加热或加热功率超过800 kW时,钢水流动特性均较差;当通道加热功率为300、600或700 kW时,钢液流动特性良好。当中间包无感应加热时,浇铸区出现明显的温度分层现象;当加热功率为500~700 kW时,浇铸区温度分布均匀且基本消除了其右上方及右下方区域的温度分层。当加热功率在400~700 kW时,夹杂物去除率呈上升趋势;但当加热功率超过700 kW后,夹杂物去除效果变差,700 kW为最佳去夹杂加热功率。     

温压模具感应加热的基础研究

本文通过过程对感应加热理论的分析,建立了温压模具的感应加热模型,用ANSYS软件对模具感应加热过程进行了温度场模拟,得出了模具内外壁温度随时间的变化规律.并通过试验验证了温压系统中感应加热的可行性.     

感应加热技术在酒钢镀锌机组的应用

酒钢镀锌机组中的带钢加热采用了感应加热技术,本文对该技术使用情况进行了介绍,论述了感应加热模型的建立过程,体现了感应加热技术的优越性,最后总结了运行中的常见故障及处理方法。     

热轧球扁钢快速感应加热技术及装备开发应用

鞍钢重机公司采用快速感应加热技术,对鞍钢股份大型厂生产的热轧球扁钢淬火工艺进行了研究,设计开发出淬火生产线,对电源频率、加热方式、感应器等设备及工艺参数进行了选择确定。该产线投入运行后,产品性能指标完全符合标准要求,淬火质量稳定,证明快速感应加热技术在型材的热处理方面具有广泛的应用前景。     

Y型三辊轧机带温连轧难变形钢丝新技术研究

本文着重介绍了钢丝感应加热设备和Ｙ型三辊微型连轧机的结构及工艺特点，以金属塑性变形理论为依据，阐述了冷拉，冷连轧，温拉，温连轧的不同加工原理，分析了各种生产方式的优缺点，从理论和实践上论证了钢丝感应加热－Ｙ型三辊轧机带温连轧难变形易裂钢丝的可能性，为难变菜钢丝的生产，为挽救被冷加工工艺判为废次品的难变形线材，改善难变形易裂钢丝的质量，提高其成材率和经济效益，指出了一条新的途径。     

中间包感应加热的数值模拟

为了研究通道式感应加热中间包的加热效率和流场的分布情况,对通道式感应加热中间包进行电磁场、流场、温度场耦合计算分析,在此基础上提出了1种新的弧形通道设计方式。计算得出:直线型通道式感应加热中间包在加热功率1 000kW的情况下,升温速率可达2℃/min;而弧形通道的设计加热效率更高,平均升温幅度比直线型通道高2~5℃,且死区面积减小,浇铸区温度分布更加均匀。     

汽车用细丝径油淬火55SiCr弹簧钢丝的感应回火工艺研究

为得到适配细丝径油淬火弹簧钢丝的感应回火工艺,满足国家绿色发展理念,研究收线速度和感应回火温度对直径5.4 mm油淬火55SSiCr弹簧钢丝微观组织和性能的影响,采用金相显微镜、扫描电子显微镜、微机控制电子万能试验机等对钢丝的微观组织、力学性能进行测试.结果发现:存在一个较优的感应回火工艺,收线速度、感应加热功率、回火温度分别为5 m/min、4.44 kW和460℃,可使钢丝回火后的组织分布均匀、片层间距致密,针状形貌明显、马氏体特征基本消失,综合力学性能优异.感应回火后弹簧钢丝的抗拉强度为1864 MPa,位于国标中限,屈强比、面缩率分别为0.92和54％,远超国标要求,平均维氏硬度为528 HV,且分布均匀.     

中板加热炉温度场计算机仿真研究

钢坯在加热炉的加热过程是影响设备运行和产品质量的关键环节。为了评估钢坯加热性能和进一步分析钢坯在加热过程中的变化，以加热炉及钢坯作为研究对象，利用ANSYS商业软件对加热炉内钢坯的温度分布进行了动态模拟计算。通过模拟分析，得到了钢坯在加热炉中不同时间与位置的温度分布，经实测验证，计算结果与实际加热情况吻合较好。研究结果对调整加热炉模型参数和提高温度控制精度具有指导意义。     

高频直缝焊管中频热处理参数分析

为减小热影响区域残余应力集中,提高焊缝质量,高频直缝焊管需进行中频热处理.但在中频感应加热后,焊缝上下表面存在一定的温差,受传热顺序的影响,厚壁管材的下表面不易达到热处理温度,严重时会影响成品钢管质量.根据焊管中频电磁加热特点,分析了两组线圈轴向间距、线圈翻转角度和主、副线圈间距对感应加热效果的影响规律.焊缝上下表面温...     

Analysis of Strip Temperature in Hot Rolling Process by Finite Element Method

 The program was developed by finite element method to calculate the temperature distribution in hot strip rolling. The heat transfer coefficient of air cooling, water cooling and thermal resistance between work roll and strip were analyzed. A new heat generate rate model was proposed according to the influence of source current density, work frequency, air gap and distance to edge on induction heating by finite element method (FEM). The heat generate rate was considered into the thermal analysis to predict the temperature distribution in the induction heating. The influence of induction heating on the strip temperature was investigated with different strip thicknesses. The temperature difference became more and more obvious with the increase of thickness. The strip could be heated quickly by the induction heating both in surface and center because of the thermal conductivity and skin effect. The heat loss of radiation has important influence on the surface temperature. The surface temperature could be heated quickly with high frequency when the strip is thicker.     

用田口方法确定U75V重轨钢脱碳关键影响因素的研究

针对U75V重轨钢的脱碳层超标问题,通过实验研究了U75V重轨钢钢坯在加热过程中加热温度、保温时间与钢坯脱碳层深度的关系。采用田口方法进行关键影响因素分析,根据各试验条件的S/N比,推断出加热温度是影响U75V重轨钢脱碳层深度的主要因素。     

The Influence of Oxide Scale on Heat Transfer during Reheating of Steel

The present work presents methodology and development of a mathematical model for prediction of the influence of oxide scale on heat transfer during reheating of steel in an industrial furnace. In this developed model, temperatures inside the steel billet were measured and with thermocouples at selected places and were collected by a water cooled computer that was traveling inside the slab. CFD is used to calculate the flow field inside of a furnace. The mass‐transfer coefficient of the scale formation is obtained by solving the convection mass‐diffusion equation across a boundary layer to the surface of a flat plate. A model for inverse heat conduction is employed to calculate the local surface temperature and heat flux on top of the growing oxide scale layer on a slab moving through a walking beam reheating furnace. By using the inverse method, the transient temperature and heat flux was firstly determined on the surface of the steel. During subsequent computations, the growth of the scale was calculated and the surface temperature of the oxide scale was extracted by using the Cauchy data from the previous calculations. The sensibility of the model on steel physical parameters is studied, and suitable parameters were obtained for heating a low carbon steel plate in the reheating furnace. Results show that the oxide scale layer should not be neglected in reheating models.     

轧钢加热炉节能改进

加热炉为轧钢系统中的能耗大户,其能耗约占轧钢总能耗的70％。介绍了宣钢轧钢加热炉从提高保温设计和提温的调火操作、充分利用原料的一次热能以及合理控制日常较长时间的工艺检修等措施,每吨钢节约煤气9．72kgce,每年效益665万元,实现了节能降耗的目的。     

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A 2D temperature model was proposed for heating rules and real-time calculation during heating process on billet reheating furnace, which included furnace temperature calculation along furnace length, billet surface fluxes calculation and conduction calculation inside billet. First, furnace temperature was accomplished according to thermocouple. Then fluxes on the above and below surfaces were calculated by total heat exchange factor method, as well as lateral fluxes. ADI and TDMA algorithms were adopted to calculate billet internal temperature distribution. Validation was carried out by thermocouple experiments and a model system was established in a hot rolling plant to provide appropriate heating rules and real-time temperature prediction. It shows precision and responsibility during reheating furnace production.     

Al-CaO复合发热剂的热效率及辅助效果

使用 Al-Ca O作发热剂在中频感应炉内进行了钢液升温的实验研究 .对实验中影响升温热效率的因素进行了分析 ,在工业生产中本复合发热剂中铝的升温热效率可达 87% .在实验基础上 ,针对升温过程中钢液化学成分的变化还对 Al-Ca O复合发热剂的辅助效果进行了分析 ,得出了使用Al-Ca O作发热剂对钢液进行升温是可行的 ,升温同时兼具脱硫效果 ,并能有效防止连铸时中间包水口结瘤 .