黄铜/铝双金属轧后厚比预测的神经网络模型

采用正交实验方法，对不同原始厚度、不同原始厚比和压下率的复合板进行轧制实验，发现不同的轧制工艺条件对成品厚比影响较大。对试验数据进行了神经网络建模。训练发现，在目标函数为0．05、隐层节点数为5、学习率为0．1时，系统误差较小。利用所建立的网络模型对其它8组不同实验条件下的成品厚比进行了预测，发现预测数据与实验数据吻合良好(总拟合度为8．7％)。说明神经网络模型很适合拟合轧制工艺参数和双金属板厚度比之间的非线性关系。     

连铸连轧过程中SPA-H钢板表面的氧化锈蚀

利用光学显微镜、扫描电镜、能谱和XRD衍射物相分析等手段,研究了SPA-H钢经连铸连轧后表面黄色锈斑的形成原因.结果表明,黄色锈斑的外层主要由Fe2O3、里层由FeO组成,在钢板表面呈条带状分布;而无黄色锈斑的钢板表面主要是由FeO组成.黄色锈斑是由于在轧制过程中,钢表面的高温氧化产物（FeO）破裂,在随后的冷却过程中破裂处特别是裂纹的尖端形成大量的Fe2O3所致,高温氧化产物FeO的应变速率和该氧化膜的横向生长比较高,高温氧化膜开裂后,裂纹不能自愈,较低温度时合金表面发生了线性氧化.     

钢中针状铁素体及其非均匀形核机制

针状铁素体钢具有优良的强韧性、抗低温断裂的综合力学性能,受到广泛的关注。本文从针状铁素体的晶体学结构和微观相组成等方面,分析了针状铁素体钢具有良好综合力学性能的主要原因。重点探讨了钢中针状铁素体非均匀形核的机制,以及影响针状铁素体形核的一些主要因素,并提出了在该领域的一些展望。     

Effects of cryogenic treatment on mechanical properties and microstructure of Fe-Cr-Mo-Ni-C-Co alloy

Fe-Cr-Mo-Ni-C-Co alloy was quenched in liquid nitrogen and held for 24 h. Hardness tester, OM, XRD, SEM were used to investigate the mechanical properties and microstructures of the alloy. The results show that the hardness increases by 1-2 （HRC） and the compressive strength decreases slightly after cryogenic treatment. The increase in hardness is attributed to the transformation from austenite to martensite and the precipitation of the very tiny carbide η-Fe2C. The decrease in compressive strength is caused by residual stress. The great amount of carbides, such as Cr7C3 and Fe2MoC, in the alloy and the obvious difference in thermal expansion coefficient between these carbides and the matrix at the cryogenic temperatures lead to this residual stress. The microscopy of cryogenic martensite is different from that of the non-cryogenic martensite. The cryogenic martensite is long and fine; while the non-cryogenic martensite is short and coarse. There is obvious surface relief of the cryogenic martensite transformation. It is not orientational of this kind surface relief and the boundary of this surface relief is smooth and in a shape of butterfly. The surface relief in the non-cryogenic martensite is wide and arranged in parallel, and the boundary of surface relief is not smooth. These characteristics may imply different growth ways of the two kinds of martensite.     

电信网络资源管理系统的建设

本文介绍了电信网络资源管理系统的体系结构和功能要求,结合安徽电信网络资源管理系统的建设,重点论述了网络资源管理系统的动态管理和应用.     

合肥地区交换机间网同步建设情况

合肥地区交换机间网同步建设情况□方文胜当前全国数字同步骨干网正在建设，合肥地区在１９９６年底建成网上等级为加强２Ａ级的ＢＩＴＳ系统（大楼综合定时供给系统）．为了打好同步网基础，我们首先做好了本地网内数字程控电话交换机之间的时钟同步工作．１交换机同步情...