M1432A型万能外圆磨床数控化改造技术

通过对M1432A型万能外圆磨床的机械部分进行改造,并增设了数控系统,将其改造成为简易的数控外圆磨床,介绍了改造中要注意的问题。用改造后的磨床可提高加工精度,扩大加工范围,提高生产率。     

经济型数控改造中提高伺服系统控制精度的方法

为了提高经济型数控机床加工精度,以CA6140型普通车床的数控改造为例,从步进电机驱动和机械传动两方面阐述了提高伺服控制精度的方法.改造后的车床投入使用后,运行稳定,加工精度明显提高,取得了较好的经济效益.     

锯床的数字化改造

为了提高老式带锯床的精度和自动化程度，对锯床的角度测量部分进行了数字化改造。经过改造，锯床的精度得到了提高，可精确地测量和显示转台所在的角度；同时，通过对驱动控制部分的简单设计，可使锯床在键盘输入角度信号后，控制转台自动地转到此位置。     

CA6140车床的数控改造

介绍了普通车床的数控改造条件，同时介绍了对CA6140车床的主传动系统和进给传动系统进行了数控化改造的过程。改造后的数控车床的加工能力、自动化水平和加工精度明显提高。同时介绍了该车床机电联动调试的经验。     

大型模锻液压机活动横梁同步平衡系统的改造

我国于七十年代初投产使用的大型模锻液压机同步平衡系统,存在动特性差、系统复杂,结构笨重等问题。为充分发挥主机性能,对其进行了改造。改造的新系统为继电特性自调系统,根据有负载与无负载状况下系统参数等传递函数的变化,采用了变参数的调节方式。改造后的新系统达到了较高的质量指标,其稳态精度比七十年代中后期苏联为法国制造的六万五千吨模锻液压机同步平衡系统的精度提高了一个数量级。本文即简介改造方案选择、理论分析以及在大型液压机上所进行的试验研究工作与取得的技术经济效果。改造后的系统已使用两年,运转情况良好,可供设计研究新的大型液压机设备和改造其他大型液压机设备参考。     

板坯连铸机高效改造研究与应用

主要阐述了莱钢炼钢厂为适应后线宽带轧制产能需要,提升设备保障精度,与中冶连铸共同对新区2号板坯连铸车间进行了高效改造的设计和实施,通过对结晶器、二冷系统、振动台等方面的改造和改进,使单机年产量具备了200万t钢的水平。     

手动剪板机的自动化改造

旧式剪板机中放料机采用手动控制,存在很多弊端。为此,应某汽车部件生产企业的要求,尝试几种改造方案,最终采用伺服电机后挡板定位系统代替传统电机,对剪板机进行自动化改造,提高了精度和自动化程度,减轻了工人的劳动强度,提升了生产效率。     

可逆式轧机主电机集电环故障分析及改造措施

本文着重对可逆式主电机集电环故障原因进行了分析,结合电机集电环运行故障处理情况,提出改造措施。改造了把接螺栓的方式和材质,提高了集电环的加工精度,改进了集电环的安装工艺,应用情况表明改进后机组运行良好。     

变频系统对于辊锻机机械手的改造与应用

为了提高旧型号的辊锻机机械手的运行精度和工作效率,本次改造将机械手纵向运动的液压驱动方式更改为变频调速驱动方式。突出介绍了改造中所用变频系统的组成与功能特点。在硬件设计中需要注意,在搭建系统时要保持变频器信号的稳定性与消除对周边信号的干扰等;在软件设计中,给出了几个重要参数的含义,并且编写了PLC梯形图。整个系统改造后,实际运行流畅,并且通过负载测试,变频系统元器件参数正常。通过本次改造可以得出:变频系统不仅能简化控制系统的硬件构造,并且还提高了设备的运行精度,减少了维护成本。改造后的系统使机械手运行更高效,也满足设备在当前自动化控制中控制灵活、可扩展等的需求。     

C6132普通车床数控化改造及电气控制设计

以C6132型普通车床为研究对象,采用GSK928TE数控系统对C6132型普通车床进行数控技术改造的方法,成功地将C6132型普通车床改造成为C6132型数控车床.阐述了GSK928TE数控系统的系统配置、功能及GSK928TE数控系统在普通车床上的应用,讨论了C6132型普通车床电气控制设计的改造及其改造后的效果.改造后的数控车床系统分辨率纵向为0.001mm,横向为0.0005 mm,大大提高了机械零件的加工精度.为企业技术改造提供了一种途径.     

Interpretation of hot rolling and cold rolling texture in high purity aluminium

In high purity aluminium two different types of hot band textures were produced by changing the final hot rolling temperatures. The texture of the hot bands was found to be inhnmogeneous through thickness. The strong preferred orientation of {001}<110> developed in the surface layer of the hot band which had been rolled at the higher finishing temperature. For the lower finishing temperature sample, the cold rolling type of texture was formed in the hot band. The cold rolling texture was dependent on the initial hot rolling texture. The hot band which had strong {001}<110> at the surface layer led to the maximum orientation density at {44 11}<11 11 8> after the subsequent cold rolling. Preferred orientations near {123}<634> in the hot band caused the maximum at {123}<634> in the cold rolling texture. The experimental results were discussed based on the simulation test of deformation texture in which the rotation of orientations was calculated from the Taylor model. In this calculation, the strain state of the deformation zone in the rolling gap is assumed to vary with shears induced from the geometry and the friction.     

铁素体轧制对普通用冷轧钢板组织和性能的影响

采用光学显微镜和扫描电镜对比研究了铁素体区热轧工艺及奥氏体区热轧工艺对普通用冷轧钢板(SPCC)产品热轧组织、冷轧组织及性能的影响。结果表明,与奥氏体区轧制工艺相比,采用铁素体区热轧工艺生产的SPCC热轧板晶粒尺寸会增大约17 μm,{111}面织构数量减少了8.74%,强度略微降低,而{001}<110>织构数量增加了12.40%,强度提高了19.81。此外,采用铁素体区热轧工艺生产的SPCC成品晶粒呈近似等轴状,与奥氏体区热轧工艺相比平均晶粒尺寸增大了4.5 μm。SPCC铁素体区轧制热轧板中更大的晶粒尺寸、更少的{111}面织构及更强的{001}<110>取向织构导致了冷轧成品更低的屈服强度和塑性应变比r值,较奥氏体区热轧工艺而言平均屈服强度降低了19 MPa,平均r值下降了1.1。     

20CrMnTi热轧带钢带状组织的控制

20CrMnTi热轧带钢直接作为适宜规格齿轮原料在可加工性和使用性能上具有显著优势,但带钢中的带状组织缺陷是影响其使用性能的关键因素。通过板坯加热均质化控制试验、精轧变形量及变形速率控制试验及轧后控制冷却试验,对20CrMnTi热轧带钢带状组织进行了分析。结果表明,20CrMnTi板坯加热时应保证心部温度大于1 000 ℃,保温时间在150 min以上;采用奥氏体再结晶轧制工艺,终轧温度控制为930 ℃,卷取温度控制为670 ℃,可有效控制成品带钢带状组织级别在3级以内。     

基于GA-PELM的板材热连轧轧制力预测

在板材热连轧过程中,轧制力的计算精度直接影响板带钢的实际厚度,也是实现精准在线控制的前提.然而,由于实际的轧制过程受多种因素影响,使用传统模型进行预测的精度往往比较低.为了提高轧制力的预测精度,提出了并行异构极限学习机(PELM)的轧制力预测模型,该模型学习速度快且泛化能力强,同时为了保证模型的稳定性,采用遗传算法(G...     

Cube orientation in hot rolled high purity aluminum plate

X-ray diffraction and orientation mapping in EBSD measurement were applied to obtain information of deformation and recrystallization with the emphasis on the cube orientation in hot rolled high purity aluminum plates.It is shown that cube orientations are retained to a large extent during hot rolling.Some deformed cube grains are found to have experienced large extent of recovery according to their Kikuchi band contrasts.The deformed cube-oriented grains in hot rolled plates are in an unfavorite growth condition with respect to their neighboring grain orientations for the subsequent annealing.The reasons for the phenomena observed,as well as the influence of hot rolling process on subsequent cold rolling and final annealing were discussed.     

Recrystallization texture characteristic and drawability of a warm rolled and cold rolled interstitial-free steel

The recrystallization textures and drawability in an interstitial-free (IF) steel were investigated as a function of cold rolling reduction. The hot bands for further cold rolling were obtained by lubricated hot rolling in the ferrite region. The orientation distribution function (ODF) was applied to analyze recrystallization textures. Texture analysis showed that hot bands rolled in the ferrite region had strong {111}//ND texture component. The {111}//ND recrystallization texture of the cold rolled steel with 73% reduction displayed the highest intensity, but weakened as more cold work was introduced. The highestr-value was obtained at a cold reduction of 73% when the hot band was previously rolled in the ferrite region.     

铝带热连轧的工艺过程自动控制

热轧的自动化控制系统对轧制过程的稳定和带坯的精度起着十分重要的作用。目前国外在热连轧机上，已普遍采用以数学模型为基础的工艺过程控制系统（LEVEL2级）进行自动轧程表计算和轧机的设定值计算。论述了热连轧机自动化控制系统的组成，重点分析了LEVEL2级的功能及轧制策略和自动轧程表在带坯控制凸度和板形中的具体作用。     

热作模具修复层表面滚压加工研究进展

热作模具因工作环境恶劣,在服役过程中易出现失效,造成资源浪费和成本升高。热作模具修复工艺可以延长其使用寿命、提高生产效率,修复层需经加工才能在表面质量和尺寸精度上满足使用要求。滚压加工是一种经济高效的光整强化工艺,通过滚压工艺可以提高热作模具修复层力学性能和使用性能,对热作模具修复层滚压加工的研究逐渐成为当前的研究热点。介绍了热作模具常见的失效形式和性能要求,从修复预处理、修复方法、修复后处理三方面概述了热作模具修复工艺研究现状,综述了修复层滚压加工研究现状,分析了传统滚压存在的问题,对滚压工艺的发展和热作模具超声滚压研究进展进行了介绍。在此基础上,对热作模具修复层的超声滚压加工研究进行了展望。     

热连轧机的设定模型与试验研究

为了使热连轧机的厚度控制系统满足较严格的厚度公差要求,新建了轧制力模型并引入了绝对值AGC。在轧制力模型结构中考虑了相变和累计应变对轧制坯料变形抗力的影响和厚度方向的温度分布。试验表明,热轧产品的厚度精度得到了很大改善。     

Process technology for the continuous hot band annealing of 17%Cr ferritic stainless steel

As an alternative to time- and energy-consuming batch annealing, process technology for the continuous hot band annealing of 17%Cr ferritic stainless steel has been established. Process parameters (i.e., temperature and time) for the hot band annealing were optimized in the laboratory and, subsequently, plant trials were conducted. The impact toughness value of the annealed hot band was found to be the most crucial parameter to assess the cold rollability in the commercial run. When the hot bands were continuously annealed at 900 °C, the improved impact toughness values resulted in successful cold rolling to the desired thickness. The impact toughness value and subsequent cold rollability were found to be related to the formation of martensite volume%. Annealing the hot band in the lower temperature range of the two-phase (α+r) region (i.e., 900 °C) yielded the best result. Improvement in roping index has been reported as a result of the weakening of the texture of the continuous-annealed hot band.