水射流表面改性对国产Zirlo锆合金包壳管加速腐蚀氧化膜形貌的影响

为进一步提高国产锆合金包壳管性能,提高反应堆安全性,对国产Zirlo锆合金进行水射流冲击强化,研究在高温高压水腐蚀条件下不同冲击压力对样品表面氧化膜的影响,并与未冲击样品进行对比。结果表明,样品表面在不同压力的冲击下耐蚀性差异较大,当冲击压力达到40 MPa时样品表面氧化膜状态较好,相比于未冲击样品氧化膜厚度减少4.3%,在10 MPa和20 MPa冲击下则出现腐蚀加速情况。     

Bulging in incremental sheet forming of cold bonded multi-layered Cu clad sheet: Influence of forming conditions and bending

Bulge is a defect that causes geometrical inaccuracy and premature failure in the innovative incremental sheet forming (ISF) process. This study has two-fold objectives: (1) knowing the bulging behavior of a Cu clad tri-layered steel sheet as a function of forming conditions, and (2) analyzing the bending effect on bulging in an attempt to identify the associated mechanism. A series of ISF tests and bending analysis are performed to realize these objectives. From the cause-effect analysis, it is found that bulge formation in the layered sheet is sensitive to forming conditions in a way that bulging can be minimized utilizing annealed material and performing ISF with larger tool diameter and step size. The bending under tension analysis reveals that the formation of bulge is an outgrowth of bending moment that the forming tool applies on the sheet during ISF. Furthermore, the magnitude of bending moment depending upon the forming conditions varies from 0.046 to 10.24 N·m/m and causes a corresponding change in the mean bulge height from 0.07 to 0.91 mm. The bending moment governs bulging in layered sheet through a linear law. These findings lead to a conclusion that the bulge defect can be overcome by controlling the bending moment and the formula proposed can be helpful in this regards.     

Effect of clad ratio on interfacial microstructure and properties of cladding billets via direct-chill casting process

Numerical simulation and experiments were introduced to develop AA4045/AA3003 cladding billets with different clad-ratios. The temperature fields, microstructures and mechanical properties near interface were investigated in detail. The results show that cladding billets with different clad-ratios were fabricated successfully. Si and Mn elements diffused across the bonding interface and formed diffusion layer. With the increase of clad-layer thickness, the interfacial region transforms from semisolid–solid state to liquid–solid state and the diffusion layer increased from 10 to 25 μm. The hardness at interface is higher than that of AA3003 side but lower than that of the other side. The bonding strength increased with the clad-layer thickness, attributing to solution strengthening due to elements diffusion. The cladding billets were extruded into clad pipe by indirect extrusion process after homogenization. The clad pipe remained the interfacial characteristics of as-cast cladding billet and the heredity of clad-ratio during deformation was testified.     

聚丁二烯环氧树脂的应用研究

使用数均分子量为2300,1,4-结构40%,1,2-结构60%的聚丁二烯环氧树脂与苯乙烯马来酸酐、溴化环氧树脂配合制作覆铜箔层压板(CCL),并对覆铜箔层压板的性能做了表征。研究了聚丁二烯环氧树脂含量对覆铜箔层压板的剥离强度、介电性能、耐热性能以及吸水率的影响。结果表明,聚丁二烯环氧树脂的加入有望提高覆铜箔层压板的可靠性。     

大型焦炭塔设计特点介绍

对延迟焦化装置中焦炭塔设计参数、壁厚、防腐层及裙座与壳体连接的结构形式进行介绍,重点分析裙座结构,对其优缺点进行了阐述。     

Interfacial Microstructure and Mechanical Properties of Al5052/Mg-9.5Li-2Al Alloy Clad Plates

通过冷轧制备出了Al5052/Mg-9.5Li-2Al合金复合板,研究了复合板退火后的组织与力学性能。结果表明:退火后复合板的结合界面上没有出现类似裂纹或孔洞的缺陷。经623或623 K以上的温度退火后,合金复合的界面形成反应相。Mg-9.5Li-2Al板和Al5052板之间结合界面处的主要反应相依次为α-Mg+β-Li相、Mg17Al12相、Li-dissolved Al3Mg2相和α-Al。在一定温度范围内,随退火温度的升高,界面结合强度逐渐增加。当退火温度为623 K时,复合板的结合强度达到最大值17.83 MPa,而且具有良好的塑性,延伸率达到18.7%,另外,界面未出现剥离现象。当退火温度为673 K时,覆板的拉伸性能由于界面剥离而恶化。     

水平连续铸造工艺对3003/4045复层管界面特征的影响

采用水平连续铸造技术制备3003/4045铝合金复层管坯,探讨了铸造速度、外层合金浇注温度和气体保护对复层管界面结合质量的影响,并对结合界面的形貌、元素分布和结合强度进行分析。结果表明,当铸造速度为180 mm/min、外层合金浇注温度为700℃并对内层管坯施加气体保护时,可成功制备出界面实现连续均匀冶金结合的复层管。拉伸剪切实验中变形与断裂发生在界面附近强度较低的3003合金侧,表明界面剪切强度大于3003合金的剪切强度。     

电磁场下AA3003/AA4045铝合金复层管坯水平连铸技术

采用数值模拟方法研究在电磁场下AA3003/AA4045铝合金复层管坯的水平连铸制备过程。为了考察电磁场对复层管坯水平连铸过程的影响,建立一个三维分析模型并对有无施加电磁场时的两个水平连铸过程分别进行全面地模拟与分析。数值模拟结果表明：施加旋转电磁搅拌后,铝合金熔体的紊流作用增强,糊状区的范围增大,糊状区的温度梯度减小且温度场变得均匀,铝合金熔体的固相率下降。这些改变有利于复层管坯组织的细化及复合界面元素的扩散。采用与数值模拟相同的工艺参数进行实验,结果证实在电磁场作用下复层管坯组织得到细化并且复合界面的元素扩散作用增强。     

二层型挠性覆铜板用聚酰亚胺的研究进展

电子行业的快速发展对二层型挠性覆铜板的性能提出了更高的要求,针对以聚酰亚胺薄膜为基底材料的二层型挠性覆铜板,分别从改善粘结性能、介电性能和耐热性能3个方面综述了二层型挠性覆铜板的研究进展,并展望了二层型挠性覆铜板的研究方向。     

Incoloy825+12Cr2Mo1R复合板封头冲压加工研制

煤焦油深加工项目中的核心设备沥青预处理塔设计材料为Incoloy825(复层)+12Cr2Mo1R(基层)复合板。由于材料的特殊性和使用工况的复杂性,要求成形后封头即耐热又耐蚀。封头成形是本设备制造中的难点。采用高温热冲压成形和随后的正火加回火热处理,封头的各项技术指标达到了设计要求。文中介绍了复合板Incoloy825+12Cr2Mo1R材料特性,封头成形工艺,热处理工艺和合格指标。