Influence of Production Sequence of Aluminum Alloy Hot Rolling on Strip Surface Quality

With the intensification of market competition in the aluminum alloy strip processing industry,it is dif-ficult to control the mass production of the same specifications,which is bound to affect the hot rolling production.This paper studied the effect of the hot rolling order of aluminum alloy on the surface quality of strip,such as roll printing,color difference,anodic oxidation,etc.,reasonable discharge sequence and corresponding optimization measures were formulated.

Head Curvature of Pure Titanium Sheet Influenced by Process Parameters and Controlling in Hot Rolling Process

We investigated the influences of process parameters on the head curvature of pure titanium sheet in hot rolling process and proposed the controlling means. First, the thermal simulation experiments for pure titanium TA1 were carried out to investigate the hot deformation behaviors of pure titanium in the temperature range of 700-800 ℃ with strain rate range of 1-20 S-1, and the processing map was established to determine optimized deformation parameters. Then, the finite element model has been constructed and used to analyze the effect of process parameters on the direction and severity of head curvature of pure titanium sheet. The process parameters considered in the present study include workpiece temperature, work roll diameter, pass reduction, oxide scale thickness of workpiece surface, and interface friction coefficient. The simulation results show that the workpiece temperature and the interface friction coefficient are the two main factors. The proposed controlling means was carried out on a hot rolling production line and solved the head curvature problem effectively. The rolling practices indicate that the rolling yield is improved greatly.

Corrosion Resistance and Tribological Properties of Laser Cladding Layer of H13 Die Steel Strengthened by Ultrasonic Rolling

Laser cladding is a new surface repair method that can improve the wear and corrosion resistance of substrate surfaces.However,the cladding layer typically exhibits a rough surface,high hardness and large residual tensile stress,and thus requires further machining and finishing.Ultrasonic rolling(U-rolling)is a highly efficient finishing and strengthening process that combines ultrasonic technology with traditional rolling(T-rolling).In this study,an ironbased alloy was coated onto the surface of H13 die steel using laser cladding,and the surface of the cladding layer was polished using U-rolling.The effects of U-rolling on the surface quality,corrosion resistance and friction and wear properties of the laser-cladding layer were investigated and compared with those obtained by T-rolling.The surface roughness of the U-rolled sample was only 1/4 that of the T-rolled sample.The hardness and residual compressive stress of the laser cladding layer after U-rolling were higher than those after T-rolling.Similarly,the surface corrosion resistance of the laser cladding layer after U-rolling was higher than that after T-rolling.U-rolling changed the surface roughness,grain size,and residual stress of the material and thus affected the corrosion resistance of the laser cladding layer.The friction coefficient and wear rate of the U-rolled surface of the cladding layer were lower than those of the T-rolled surface.In addition,the tribological properties of the cladding layer were found to be related to the rolling direction.When the friction direction of the sample was the same as the rolling direction,its friction and wear performance were higher than those when the two directions were perpendicular.

Auto Identification of Rolling Layers in Roller-Compacted Concrete Dam

A scheme for identifying rolling layers in roller-compacted concrete (RCC) dam automatically was presented. First, a conceptual model was developed. Second, by using a computational geometry method, the auto identification of rolling layers and auto matching between rolling compaction machines and rolling layers were realized based on spatial control points. An application to the construction of Guandi RCC dam showed that the auto identification of rolling layers played an important role in ensuring the engineering quality.

Effect of rolling geometry on the mechanical properties, microstructure and recrystallization texture of Al–Mg–Si alloys

The effect of rolling geometry on mechanical properties, microstructure, and recrystallization texture of Al-Mg-Si alloys was studied by means of tensile tests, microstrucmral observations, and electron backscatter diffraction measurements. The results reveal that the elongation and the average plasticity strain ratio （r） values of the T4P （pre-aging plus natural aging）-treated alloy sheet with a rolling geome- try value between 1 and 3 are somewhat higher than those of the T4P-treated sheet with a rolling geometry value between 3 and 6. The deformation and recrystallization microstructures of the sheet with a rolling geometry value between 1 and 3 are more uniform than those of the sheet with a rolling geometry value between 3 and 6. The former also possesses somewhat higher surface quality. H {001 } 〈110〉 and Goss {110}〈001〉 orientations are the main recrystallization texture components for the former case, whereas the latter case only includes H {001 } 〈 110〉 orientation. Texture gradients are present in the two alloy sheets. Shear texture component F on the surface of the sheet with a rolling geometry value between 3 and 6 and its higher texture gradients have revealed that non-uniform deformation occurred during cold rolling. The effects of texture on the yield strength and r value were also discussed.

Analysis of the influence of the hot-rolling material on galvanized product

Hot-rolled galvanized steel sheet is made from hot-rolled pickled sheet by continuous hot-dip galvanizing process.Without the cold-rolling process,it greatly reduces the operating costs and saves investment for shorter process and lower energy consumption.The economic advantage is obvious.The characteristics of high-yield and low cost will greatly enhance the competitiveness of enterprises in the market.There are big differences between the substrates of hot-rolled galvanized steel sheet and cold-rolled galvanized steel sheet in surface roughness,chemical elements,and surface defects.These factors directly affect on the quality of galvanized sheet.Pickling process is used to remove the oxide layer which is formed on the surfaces of hot-rolled steel sheet.The surfaces must be thoroughly cleaned for the oxide layer will seriously affect the adhesion of galvanized coating.Residual impurities,Carbon concentrating and other problems must not be caused during pickling as well.Therefore,the quality of galvanizing depends on the quality of pickled sheet surfaces.Experimental methods such as AES,XPS,SEM,OM are employed during the research for detailed analysis on the effects of hot-rolled plates and hot pickling plates on the quality of hot-rolled galvanized products.

高铁轴承钢的技术质量特性识别及重点研制方向

从相关标准规范、主要故障模式及在用轴承技术状态等多个维度对高铁轴箱轴承用钢的技术性能要求进行了梳理,进而对其核心技术质量特性进行了识别,即“强韧性、抗疲劳、耐磨性”,并对自主化研制高铁轴承钢的技术路线及改进方向给出了建议。在现阶段,集成渗碳钢与“真空脱气+电渣重熔”冶炼方法的优势,是最具合理性与可行性的解决方案。

影响冷轧板表面转化膜形成质量因素研究

磷化膜、硅烷膜是冷轧板常见的转化膜,除自身工艺对其形成质量有很大的影响外,冷轧板表面状态及形貌对其形成质量也有很大的影响。研究了冷轧板表面残油、残碳,表面夹杂物及析出相,表面缺陷,表面合金元素偏聚,表面微观形貌表征参数等对转化膜形成质量的影响,并就转化膜对电泳漆膜耐腐蚀性能的影响及未来研究方向进行了讨论。结果表明:冷轧板表面的洁净化,表面夹杂物及析出相、偏聚元素、划痕缺陷控制的少量化,表面微观形貌表征参数控制的精细化,可以提高冷轧板转化膜的形成质量。

空化超声滚压对7075铝合金表面质量的影响

目的 为了研究超声滚压加工过程中空化效应对零件表面质量的影响,方法 以车削后的7075-T6铝合金为加工对象,进行空化超声滚压和普通超声滚压工艺对比试验,使用表面粗糙度仪测量加工后的工件表面粗糙度,采用显微硬度计测量工件表面显微硬度,并用超景深测量仪测量工件表面微观形貌。结果 结果表明,普通超声滚压和空化超声滚压均能降低滚压加工后的工件表面粗糙度,增大表面显微硬度。随着静压力增大,两种超声滚压加工方式获得的表面粗糙度均呈逐渐降低趋势,而表面显微硬度均呈逐渐增大趋势。超声滚压加工通过削峰填谷作用使工件表面变光滑。相对于普通超声滚压,空化超声滚压的空化效应引起的冲击波和微射流可以进一步促进材料表层的塑性流动,使工件表面经空化超声滚压加工后能获得更低的表面粗糙度和更高的显微硬度,更加平整。在本文试验条件下,空化超声滚压加工后的表面粗糙度最低可达0.038μm,表面显微硬度最高可达210.07 HV0.1。相同静压力下,空化超声滚压加工相较于普通超声滚压加工,表面粗糙度最大可降低42.2%,表面显微硬度最大可提升2.6%。结论 试验证实了在超声滚压加工过程中引入空化效应可进一步提高工件表面强化质量。

车端侧滚减振装置对高速双层动车组动力学性能的影响分析

双层动车组设置较大的二系横向阻尼来抑制一次蛇行引起的共振,而较大的二系横向阻尼会使车辆的横向平稳性变差。针对某型高速双层动车组横向平稳性差的问题,基于车端侧滚减振装置的工作原理建立了车端侧滚减振装置在车体滚摆和摇头运动状态下的数学模型,并将AMEsim软件中建立的减振器仿真模型与台架试验进行验证。最后通过建立车端侧滚减振装置与被试车辆的联合仿真模型,在不改变车辆现有悬挂参数的基础上对车端侧滚减振装置的关键参数进行优化选取。仿真结果表明,车端侧滚减振装置可以在不影响车辆垂向平稳性、保证曲线运行安全性的前提下有效改善双层动车组的横向平稳性。

面向热轧带钢表面缺陷检测的YOLOv5算法优化分析

单阶段目标检测网络YOLOv5在处理热轧带钢表面缺陷的特征提取与感受特征融合时存在一定不足。文章提出一种适用于热轧带钢表面缺陷检测的优化YOLOv5算法,该算法通过IOUK-means++算法调整Anchor聚类锚框设定,并增加Dynamic Head目标检测头,引入通道注意力机制(C3_CA),同时结合Hard Swish激活函数与WIoU_Loss边界框回归函数,有效提高热轧带钢表面缺陷检测的综合精度。由NEU-DET数据集测试结果表明,相较于单阶段YOLOv5算法融合结果,优化后的YOLOv5网络模型的均值平均精度(mAP)可提高至75.7%,且网络约束率可有效提升6.1%。上述优化YOLOv5算法对热轧带钢表面缺陷位置勘定、分类指向与影响评估具有有益参考,同时也为金属表面的高精度筛检提供重要支持。

轻揉捻轻发酵条件下茶树品种‘湘波绿’与‘槠叶齐’红茶品质分析

采摘茶树品种‘湘波绿’‘槠叶齐’春梢一芽一叶及一芽二叶,采用轻揉捻轻发酵工艺分别制成红茶,对茶样进行感官审评与生化成分检测分析。感官审评结果表明,轻揉捻轻发酵条件下两品种红茶香气兰花香显(‘湘波绿’一芽一叶红茶)、有花香(‘湘波绿’一芽二叶红茶)、带花香(‘槠叶齐’一芽二叶红茶);条索分别较紧结(一芽一叶红茶)或尚紧结(一芽二叶红茶);汤色明亮,分别为橙红(一芽一叶红茶)或尚红(一芽二叶红茶);滋味均表现为鲜醇。一芽一叶红茶生化成分检测结果表明,‘湘波绿’红茶水浸出物略低于‘槠叶齐’红茶,氨基酸含量等则相当;两品种红茶的香气成分均以醇类含量最高,其次是酯类和醛类。‘湘波绿’红茶酯类、醇类和酸类香气化合物含量高于‘槠叶齐’红茶。‘湘波绿’一芽一叶红茶主要香气成分有香叶醇、芳樟醇、水杨酸甲酯、氧化芳樟醇Ⅱ(呋喃型)、顺-茉莉酮、氧化芳樟醇Ⅰ(呋喃型)、顺-己酸-3-己烯酯、反-柠檬醛和橙花醇,‘槠叶齐’一芽一叶红茶主要香气成分有香叶醇、芳樟醇、水杨酸甲酯、氧化芳樟醇Ⅱ(呋喃型)、顺-茉莉酮、氧化芳樟醇Ⅰ(呋喃型)、橙花醇、反-柠檬醛、顺-罗勒烯和顺-己酸-3-己烯酯;香叶醇、芳樟醇、水杨酸甲酯3种香气成分含量两品种均相当,氧化芳樟醇Ⅱ(呋喃型)和氧化芳樟醇Ⅰ(呋喃型)、顺-茉莉酮、顺-己酸-3-己烯酯、桃金娘烯醇、a-萜品醇、2,6-二甲基-5-庚烯醛、苯乙醛、反-3,7-二甲基-2,6-丁二烯酸等‘湘波绿’高于‘槠叶齐’,反-3-己烯醇、2-正戊基呋喃、苯甲醛、杜松烯、异戊酸叶醇酯、己醇、壬醛、反,反-2,4-庚二烯醛、反-2-己烯醇、1-辛烯-3-醇、紫罗酮、月桂烯等‘湘波绿’低于‘槠叶齐’。这些生化成分含量及其差异分别构成了轻揉捻轻发酵工艺条件下‘湘波绿’红茶和‘槠叶齐’红茶的品质特征。试验结果可为优质红、绿茶适制茶树品种‘湘波绿’及‘槠叶齐’的加工利用及提升红茶品质新工艺探索提供一定的启示与参考。

基于知识图谱推理的热轧带钢产品质量缺陷追溯

热轧带钢生产面临多工况、机理复杂、工艺参数繁多等问题,造成专家很难及时有效给出生产中导致质量缺陷的原因。由此提出一种基于知识图谱推理的质量缺陷追溯方法。首先通过可解释方法SHAP实现对随机森林模型预测结果的解释,并通过知识图谱将数据挖掘结果与工艺机理、专家经验等知识进行融合,进一步将图谱中表示工艺参数与质量参数依赖关系的子图映射到贝叶斯网络,推断不同工艺参数导致产品质量缺陷的后验概率。实际生产数据验证表明,针对不同生产工况,该方法能有效识别各个批次中导致质量缺陷的工艺参数,表现出良好识别率。

超薄宽镀锌家电板生产工艺优化

针对超薄宽家电板在生产过程中产生的板形、表面质量和性能等方面问题,通过微中浪控制轧制配合拉矫机两弯两矫,实现板形优化;通过优化气刀工艺参数及气源、辊系轴瓦轴套及辊面材质等措施,改善表面质量;通过成分设计、退火工艺参数控制等,满足性能要求。为超薄宽镀锌家电板的稳定高效生产提供理论依据及实践经验。

东北漫川漫岗黑土区典型农业小流域切沟沟头形态特征及其影响因素

[目的]研究中国东北漫川漫岗黑土区典型农业小流域切沟沟头形态特征及其影响因素,为控制黑土区沟壑侵蚀提供基础数据和理论支撑。[方法]以黑龙江省海伦市海南乡典型农业小流域切沟沟头为研究对象,野外实地调查沟头形态特征及土壤类型和土体构型,解析沟头形态特征与沟头内因(土壤特性)及外部环境因素的相关性,分析内外因素对沟头形态的影响。[结果](1)海南乡小流域切沟沟头土壤类型为典型黑土、草甸黑土和冲积土,土体构型以腐殖质层(A)+淀积层(B)+母质层(C)型为主,以腐殖质层(A)+母质层(C)及腐殖质层(A)+母质层(C)+埋藏层(Ab)型为辅。(2)相关性分析表明,沟头形态与内外因素呈现复杂的相关性,单一形态不仅受内外因素的影响,同时受自身形态的共同作用影响。(3)冗余分析表明,土体构型、汇水面积、沟头坡度是影响沟头形态的主要因子,且与沟头形态呈正相关关系;沟头植被覆盖度、作物距沟头距离、沟头垄向与沟头立面夹角与沟头形态呈负相关关系。[结论]切沟沟头形态特征复杂,土壤垂向差异性是内因的根本,沟头形态受内外因素共同影响。

针辊式烟丝结构调控设备参数变化对细支烟卷制品质的影响

以单支质量标准差、吸阻标准差、总通风率标准差、端部落丝量、含末率等为指标,选取选丝针辊电机频率、断丝针辊电机频率和选丝针辊间距3个参数设计正交试验,研究针辊式烟丝结构调控设备参数变化对细支烟卷制品质的影响。结果表明:选丝针辊电机频率是影响细支烟单支质量和总通风率标准差的关键因素,断丝针辊电机频率是影响吸阻标准差和端部落丝量的关键因素,选丝针辊间距是影响含末率的关键因素;调控设备最优参数为选丝针辊电机频率33 Hz、断丝针辊电机频率45 Hz、选丝针辊间距45 mm;调控后烟丝长丝率降低了14.39%、中丝、短丝率增加了26.01%和20.09%,碎丝率变化较小。卷制后细支烟物理指标无显著变化,但单支质量、吸阻、总通风率等标准差均下降30%以上,端部落丝量、含末率分别降低了61.79%和36.42%,细支烟卷制稳定性明显提高。

手卷雪茄在线质量检测技术的研究与应用

为解决手卷雪茄人工质检效率低、成本高问题,设计并实现了基于机器视觉和传感器技术的手卷雪茄在线质量检测系统。该系统首先对雪茄进行激光打标,其次系统通过高速线阵CCD相机动态获取手卷雪茄图像,基于改进的机器视觉方法实时分析雪茄茄衣颜色及瑕疵,基于微波传感器,系统采用谐振法实现手卷雪茄含水量与密度的量测,然后基于CCD激光测微仪,通过对射式LED光幕实现手卷雪茄烟支外径高速测量,最终基于高精度重量传感器实现流水线手卷雪茄的快速称重工序,实现对雪茄质量的在线自动化质检。经过测试,该系统可满足流水线工况下实时、高精度的手卷雪茄质检工作,有效提升质检效率。

基于卷积注意力特征迁移学习的滚动轴承故障诊断

针对变工况条件下因源域和目标域样本数据分布差异大造成滚动轴承故障诊断准确率较低的问题,提出一种新的迁移学习方法——卷积注意力特征迁移学习,并用于变工况条件下的滚动轴承故障诊断;在所提出的卷积注意力特征迁移学习模型中,将源域和目标域样本经过多头自注意力计算再经过归一化之后,输入到卷积神经网络中得到对应的源域和目标域特征;然后通过域自适应迁移学习网络将两域特征投影到同一个公共特征空间内;接着,利用由源域有标签样本构建的分类器进行分类;最后,利用随机梯度下降方法对模型进行训练和参数更新,得到模型的最优参数集后将参数优化后的模型用于滚动轴承待测样本的故障诊断;滚动轴承故障诊断实例验证了所提出的方法的有效性。

扭矩对无扩口导管滚压成型性能影响精细化研究

针对无扩口导管接头体内径滚压成型工艺,将三维滚压过程简化到二维平面进行分析,建立成型扭矩等效换算方程。基于ABAQUS建立无扩口导管接头二维有限元模型,对滚压成型过程进行仿真分析,得到滚压过程中扭矩阶段性变化趋势及导管受力变形区域性特征。对接头体开展连接强度试验,仿真与试验得到的连接强度差值率为5.8%,验证了仿真模型的精准性。为探究成型扭矩对接头体性能的影响规律,选取多组成型扭矩进行仿真分析,综合导管残余应力、变形分布、填充状态及连接强度等因素对接头体的成型性能进行评价。结果表明,成型扭矩取值区间为0.68~1.13 N·m,扭矩为1.04 N·m时管套最右端凹槽填充率为100%,此时接头体成型性能最优。

一种变角度摆动数控陶瓷滚压成型机的设计与试验

陶瓷滚压成型通过陶瓷滚压成型机对泥料实施旋滚与压制复合运动,是日用陶瓷成型的重要环节,对成瓷质量具有重要影响。针对传统陶瓷滚压成型机存在的滚头角度固定、成型坯体颗粒排列不均的问题,通过对滚压成型工作原理及其过程中泥料可能出现的质量问题分析,提出一种变角度数控陶瓷滚压成型机的设计方法,将传统陶瓷滚压成型机滚头轴固定角度滚压改进为滚头先垂直下压,然后以滚头末端为中心点、产生滚头轴随形变角度摆动压制的滚压过程,用以克服传统滚压成型机滚压后坯体密度不均等问题,使其排泥流畅、坯体各处受力均匀,减少烧成变形。以典型盖碗瓷坯为研究对象,开展变角度摆动与固定角度的滚压成型试验,通过烧成后的质量对比分析验证提出方法有效性。结果表明,相对于传统固定角度滚压,变角度摆动滚压成型机滚压成坯的A型盖碗烧成后的高度、口径烧结收缩率分别增加1.12%、0.73%,B型盖碗烧成后的高度、口径烧结收缩率分别增加0.11%、0.06%,说明变角度滚压机滚压后泥料底面和侧面受压力均匀,泥料致密性和均匀性更好;A型、B型坯体成品率分别提高44%、40%,成型产品质量提高,成品率大大增加。因此,提出方法对于提升陶瓷滚压成型工艺质量、减少产品变形,以及自动化和柔性化方面具有重要理论意义与工程价值。