Effect of Annealing on Fly-Line Microstructure and Properties of Explosively Composited Stainless Steel-Stainless Steel Plates

Effect of annealing on "fly-line"(adiabatic sheer line) microstructure and properties of explosively composited stainless steel-stainless steel plates was studied.Results show that the flyline microstructure will diminish through certain annealing process,while the cracks formed from fly-line microstructure will remain.Therefore,fly-line microstructure can be considered as a plastic deformation microstructure and crack source s meanwhile its formation is considered as a special plastic deformation mechanism of metal under explosive load.

Study on strip buckling in continuous annealing lines/hot galvanizing

In continuous annealing lines/hot galvanizing,strips are guided by upper and lower rolls in an alternate up and down vertical motion.This kind of process consisting of heating,soaking,and cooling furnaces(or zones) has several advantages in terms of productivity and product quality.Main problems encountered in continuous annealing lines are misguiding and formation of buckling.The strip buckling causes the strip to be rejected and,in the worst case,the strip breaks and the continuous annealing lines are compelled to stop.In this paper the elastic-plastic model of the strip traveling and the corresponding boundary condition were constructed dependant on the theory of mechanic.Simulations are performed in two steps.First,a homogeneous longitudinal tensile stress is applied at one end of the strip,the other end of the strip and the roll are restricted.In the second step,the applied tension remains constant.A uniform displacement is applied to the other end of the strip and a rotation to the roll. The transverse compressive stress,the buckling formation during strip traveling process,the location for the buckling taking place and the buckling criterion were investigated systematically.The result shows that the transverse compressive stress increases with the increase of the tensile stress and the crown of the tapered roll. Because the contact area between the tapered roll and the strip increase with the decrease of the crown,the tensile stress distribution is more homogeneous in the transverse direction of the strip.An additional transverse compressive stress is created and a buckling is also observed due to the friction during the strip motion in the second step.Once the buckling is appearance,it is very hard to be removed only through decreasing the applied longitudinal tension,because the strip wrinkle still keeps high level due to the effect of the buckled strip,the wrinkle would evolve into buckling eventually.The buckling formation process predicted by the finite element model is very similar to those observed in industrial processing lines.It takes place on the cylindrical part of the tapped roll and the buckling is moving to the middle part of the tapped roll with the increase of the crown,its width is about 2-4 mm.The criterion for the buckle occurrence is also discussed,in the prescribed situation,the transverse shell curvature increases with the strip displacement,if the transverse shell curvature reaches 0.1 mm^(-1), the buckling would take place.

Driving control technology for a continuous annealing line

This paper introduces AC variable-speed driving control technology application in the continuous annealing line,including the drive system configuration,the driving control characteristics of CAL and the main control functions of the drive system.Firstly introduces the main process of the continuous annealing line,the features of the 6SE70 series common DC bus drive system and the G150 series drive system. Secondly,for the continuous annealing line,there are more strict requirements for the continuity of production and more special requirements for the drive control characteristics.We do a lot of improvement and standardization for the driving control functions and the interfaces of the line automation control system. This paper discusses the communication interface specifications and the dimension transformation methods between the drive and the basic automation system.The detail dimension transformation methods and calculation method about the line speed setting and the actual roller dimension setting are given,and detail description for the calculation method of the reference speed in the drive.Article also emphasized illustrates realizing and testing methods of inertia compensation of equipment in the drives,and standardize the value of line accelerate and decelerate rate,and the inertia test method and inertia compensation coefficient calculation method is introduced in this paper.For the bridge rollers and furnace help rollers load balance control,this paper presents two different load balance control strategies,the load balance control principle for bridge rollers which data communicates from main station to slave stations by Simolink,and the load balance control principle for furnace help rollers which use droop control.The different characteristics of those two methods are stated in detail.

Solving Level Scheduling in Mixed Model Assembly Line by Simulated Annealing Method

This paper presents an application of the simulated annealing algorithm to solve level schedules in mixed model assembly line. Solving production sequences with both number of setups and material usage rates to the minimum rate will optimize the level schedule. Miltenburg algorithm (1989) is first used to get seed sequence to optimize further. For this the utility time of the line and setup time requirement on each station is considered. This seed sequence is optimized by simulated annealing. This investigation helps to understand the importance of utility in the assembly line. Up to 15 product sequences are taken and constructed by using randomizing method and find the objective function value for this. For a sequence optimization, a meta-heuristic seems much more promising to guide the search into feasible regions of the solution space. Simulated annealing is a stochastic local search meta-heuristic, which bases the acceptance of a modified neighboring solution on a probabilistic scheme inspired by thermal processes for obtaining low-energy states in heat baths. Experimental results show that the simulated annealing approach is favorable and competitive compared to Miltenburg’s constructive algorithm for the problems set considered. It is proposed to found 16,985 solutions, the time taken for computation is 23.47 to 130.35, and the simulated annealing improves 49.33% than Miltenberg.

Numerical simulation and combination optimization of aluminum holding furnace linings based on simulated annealing

To reduce heat loss and save cost, a combination decision model of reverb aluminum holding furnace linings in aluminum casting industry was established based on economic thickness method, and was resolved using simulated annealing. Meanwhile, a three-dimensional mathematical model of aluminum holding furnace linings was developed and integrated with user-defined heat load distribution regime model. The optimal combination was as follows: side wall with 80 mm alumino-silicate fiber felts, 232 mm diatomite brick and 116 mm chamotte brick; top wall with 50 mm clay castables, 110 mm alumino-silicate fiber felts and 200 mm refractory concrete;and bottom wall with 232 mm high-alumina brick, 60 mm clay castables and 68 mm diatomite brick. Lining temperature from high to low was successively bottom wall, side wall, and top wall. Lining temperature gradient in increasing order of magnitude was refractory layer and insulation layer. It was indicated that the results of combination optimization of aluminum holding furnace linings were valid and feasible, and its thermo-physical mechanism and cost characteristics were reasonably revealed.

高速铁路列车开行方案与票价票额综合优化

为提升高速铁路的运营组织水平和盈利能力,本文提出高铁列车开行方案与票价票额综合优化方法。首先,构建分时客流需求与票价间弹性需求函数,并分析包括出发时段偏差、乘车耗时及票价的旅客广义出行成本,进而采用多项式Logit模型描述分时弹性客流的列车选择行为。在此基础上,以客票总收入与运营总成本之差最大为目标构建三者综合优化模型。其次,利用OD总收益关于列车票价的偏导构造票价方案搜索策略,使票价邻域解和列车开行方案邻域解相适应,并运用Cplex求解对应的最优票额分配方案,设计模拟退火算法求解模型。最后,基于郑西高速铁路进行算例分析,结果表明:在7个不同弹性系数下进行综合优化,旅客出行成功率和列车平均客座率均在90%以上,优化解的列车开行方案、票价方案及票额分配方案均高度匹配;在5组不同规模算例中,三者综合优化的运营净收益相比于固定票价下的开行方案与票额联合优化和固定开行方案下的票价与票额联合优化,分别提高了4.11%~15.25%和3.17%~13.42%,且人均单位里程出行成本亦分别降低了1.69%~4.96%和0.97%~4.35%,表明综合优化更好地提升了高速铁路的运营收益和旅客服务水平。

3D NAND闪存中氟攻击问题引起的字线漏电的改进

随着3D NAND闪存向更高层数堆叠,后栅工艺下,金属钨(W)栅字线(WL)层填充工艺面临的挑战进一步增大.由于填充路径增长,钨栅在沉积过程中易产生空洞,造成含氟(F)副产物的聚集,引起氟攻击问题.具体表现为,在后续高温制程的激发下,含氟副产物向周围结构扩散,侵蚀其周边氧化物层,导致字线漏电,影响器件的良率及可靠性.本文首先分析了在3D NAND闪存中氟攻击的微观原理,并提出了通过低压退火改善氟攻击问题的方法.接下来对平面薄膜叠层与三维填充结构进行常压与低压下的退火实验,并使用多种方法对残留氟元素的浓度与分布进行表征.实验结果表明,适当条件下的低压退火,使得钨栅中的残余氟有效地被排出,可以有效降低字线的漏电指数,提高3D NAND闪存的质量.

连续酸洗机组7.0~8.0 mm厚规格酸洗产品拓展实践

近年来应用户需要,某连续酸洗机组开展了屈服强度350 MPa以下、厚度7.0~8.0mm、宽度800~1300 mm酸洗板拓展试验.通过对现有设备能力负荷计算、开展取样离线样板焊接验证以及多轮通板生产验证,确定了该机组具备7.0~8.0 mm厚规格酸洗产品的生产能力.经过生产验证,该机组生产稳定,无异常问题,7.0~8.0mm厚规格酸洗产品质量达到用户要求.

铝带连续退火机组设计与关键设备配置

文章结合某2350 mm铝带连续退火机组,对铝带连续退火机组的主要工艺参数、机组设备组成、关键设备要点等进行论述,以达到合理方案配置。

C形翘曲热轧钛带退火酸洗生产过程控制研究

热轧钛带在热轧生产过程中产生C形翘曲,在后续退火酸洗生产过程中如果不采取有效措施进行治理,将导致更严重的表面划伤,甚至因钛带过度跑偏与生产设备发生机械擦刮引发严重的生产停止、设备事故和产生废品,导致重大的经济损失。通过在退火酸洗线生产过程中采用有效控制工艺及措施,如增加压辊、托辊、保护板,辊凸度,套量控制,加热冷却工艺控制,张力-速度控制等措施进行生产过程综合治理,从而保证C形翘曲的热轧钛带在退火酸洗线安全稳定高质高效生产。

硅钢脱碳退火机组卷取机弱磁区张力优化

由于近期硅钢市场需求强劲,连续退火机组投产10年后面临提速、提质的要求,材质单层越来越薄,整卷后工序成材率、让步率,受到卷取张力的影响越来越明显,通过研究张力控制的原理及张力优化方案、建立实际作用于带钢卷取的张力模型,逐步排查出处于弱磁区的卷取机异步电机转矩精度、线性度不足,针对电机传动(逆变器)、PLC程序的优化使得转矩精度达到工艺的要求。

电控纠偏系统在冷轧酸洗镀锌产线的应用及常见故障处理

本文讲述电控纠偏系统在冷轧酸洗、镀锌带钢生产线得到了广泛应用,是酸洗、镀锌产线机组的重要组成部分,对产线的运行稳定,及有效解决带钢跑偏问题提供了有效的解决方案。

基于可用度评价的混联装配线缓冲区优化配置方法

针对具有多设备并联、多工位串联、多条子生产线串并联特征的混联装配线,提出在缓冲区总容量约束下,以最大化系统可用度为目标的缓冲区优化配置策略。通过分析缓冲区状态对各工位设备的影响,将带有缓冲区的装配线等效处理;利用通用发生函数和串并联复合算子求解系统的可用度发生函数,建立缓冲区容量与系统可用度的数学模型;最后采用遗传模拟算法求解缓冲区的优化配置方案,以某医疗公司输液针装配线为例,评估与分析算法的优化结果,验证了该方案的可行性。

宽体压延线退火窑特点及常见问题对策

宽体退火窑是与宽体压延线相配套的退火设备,其结构与普通宽度的退火窑基本相同,但由于原板宽度较大,在壳体宽度、辊子长度、温度监控系统、电加热系统、冷却风系统和退火工艺等方面存在一些差异,对宽体压延线退火窑及常见问题进行了分析,并提出了一些对策方法,为提高宽体压延玻璃退火质量提供参考。

基于时变区间断面需求的高铁网络列车开行方案优化

列车开行方案与客流需求匹配与否在很大程度上决定高铁运输服务质量和市场竞争力。为使高铁列车的开行方案与旅客的时变需求相吻合,在基于连续运输能力的高铁客流均衡分配获得区段时变断面需求的基础上,引入列车发车时间,提出基于区段列车生成和列车拼接组合的开行方案设计思路,解决大规模高铁网络列车开行方案的优化问题。首先,根据列车始发终到站需要配备动车段或存车线的特征,以配备相关设施的车站为界,将高铁网络分解为若干个互不重合的区段,并以区段为单位,提出吻合时变区间断面需求的区段开行方案生成方法和列车拼接组合策略。其次,针对网络化列车开行方案中需要满足的始发站发车能力约束、终到站终到能力约束、区间通过能力约束和列车总数约束,以高铁运营收入、高铁运营成本与旅客需求偏差的惩罚费用加权和为优化目标,构建基于时变区间断面需求的高速铁路列车开行方案优化模型,并通过4种列车调整策略和5种综合方案调整策略构造邻域解,设计模拟退火求解算法。最后,以京广高速铁路、沪汉蓉高速铁路以及郑西高速铁路为例验证模型和算法的有效性。结果表明,优化产生的列车开行方案与时变客流吻合程度高,同时也具有较高的运算效率和收敛性,适用于大规模高铁网络开行方案的设计和优化。

连续酸洗线黑印缺陷的研究与优化

通过分析某连续酸洗线发生黑印缺陷的典型事故,找出造成连续酸洗线黑印缺陷的主要原因,即带钢在运行过程中与挤干辊产生摩擦,导致挤干辊掉胶,再经由挤干辊碾压,印在带钢表面无法洗掉。针对该缺陷,在管理方面建立问题暴露机制和快速响应机制,保证缺陷发生后能够快速处理,在设备方面优化挤干辊材质和挤干辊更换周期,从根源上减少缺陷的发生率。

基于改进模拟退火算法的针织生产线调度研究

针对含有多阶段生产流程的针织服装生产线调度问题,构建包含机器资源约束和成批约束的四阶段异构车间调度模型,利用多种调度规则对相邻阶段调度流程进行衔接。提出一种基于织片排序的带有多邻域搜索和重升温操作的改进模拟退火算法,以最大完工时间最小化为目标对上述模型进行求解。结合企业实际背景构建10种混合式订单作为案例进行仿真实验,并与现有优化算法进行对比,证实了该算法在求解针织服装生产线调度问题的有效性。

改进遗传算法支持下汽车中控混流装配生产线优化数学模型构建

针对当下对混流装配生产线现存方法不足的问题,实验提出一种结合GA算法和模拟退火算法的IGA模型,用以求解汽车混流装配线的平衡问题。模型对IGA所有步骤进行了充分的解释说明,并引入模拟退火算法中的采样规则来选择操作。最终实验结果显示,优化前后,生产线平衡率提高了4.77%,生产线负荷均衡提高了3.56,平衡损耗系数降低了0.047,生产节拍降低了6.21 s。该模型能够实现装配工艺的最优分配策略,同时提升整体生产线的工作效率。

镀锌线薄板生产中退火炉的加热控制研究

基于对镀锌退火炉的加热控制功能的分析,结合生产线的实际情况,对不同规格的薄板制定出了不同的加热控制策略,即以不同的温度上升斜率来保证薄板升温过程的平稳进行。通过优化退火炉的加热控制策略,满足了镀锌薄板的生产需求。

热轧不锈钢连续退火酸洗线生产钛卷工艺实践

通过利用热轧不锈钢连续退火酸洗线进行生产钛卷工艺实践,在生产实践过程中进行工艺优化升级及设备改善改进,实现钛卷高质量稳定生产。在成材率、一次合格率、综合成本等质量经济技术指标较优。