含钼低碳微合金化钢连续冷却过程相变动力学研究

在热模拟试验机上采用膨胀法并结合金相组织观察，测定了含钼和不含钼的试验钢贝氏体转变CCT曲线。研究了超低碳微合金化钢中钼元素对形变奥氏体连续冷却转变过程相变动力学的影响，结果表明，钢中加入ω（Mo）0．4％后，明显降低贝氏体的析出温度，并得到更细小的贝氏体组织；同时在相同的冷速条件下形成的M（马氏体）岛状组织也更加细小弥散；形变奥氏体在连续冷却过程中即使在冷速较低情况下也能获得细小的贝氏体组织。     

相转变过程计算机模拟的研究与应用

总结了国内外在相转变过程计算机模拟研究方面取得的进展,分析了模拟所需要的数学模型以及实现微观组织演变过程可视化存在的问题.以高速线材82B为例,采用有限元方法模拟了其轧后控冷过程中的相转变过程,说明相转变过程计算机模拟研究工作对现场生产的指导意义.     

真空液相烧结Mo2FeB2硬质覆层材料的研究

应用真空液相烧结法在Q235钢基体表面制得了Mo2FeB2硬质覆层,并对其进行了硬 度测试、弯曲强度试验与耐腐蚀性试验.结果表明,在1200～1220℃进行烧结,覆层维氏硬度达到13170 MPa(1317 kgf/mm2),弯曲强度达到1168.21 MPa,并且具有较好的耐腐蚀性.采用扫描电镜观察了硬质覆层材料及其界面的微观组织结构,发现硬质覆层内部组织结构致密,覆层与钢基体之间形成了一个具有一定厚度的过渡层,并且两相之间形成了良好的结合界面.并对覆层的断口形貌进行了观察分析.     

Calculation and Analysis of Valence Electron Structure of Mo2C and V4C3 in Hot Working Die Steel

Taking the hot working die steel （HWDS） 4Cr3Mo2NbVNi as an example, the phase electron structures （PES） and the biphase interface electron structures （BIES） of Mo2C and V4 C3 , which are two kinds of important carbides precipitated during tempering in steel were calculated, on the basis of the empirical electron theory of solids and molecules and the improved TFD theory. The influence of Mo2 C and V4 C3 on the mechanical properties of HWDS has been analyzed at electron structure level, and the fundamental reason that the characteristic of the PES and the BIES of carbides decides the behavior of them has been revealed.     

添加青铜粉对烧结316L不锈钢组织和性能的影响

研究了添加青铜粉对316L烧结不锈钢的密度、硬度和微观组织的影响。结果表明：添加青铜粉末提高了316L不锈钢的生坯密度。烧结样品的密度和硬度均随青铜粉体积分数的增大而提高，烧结温度升高也有利于316L烧结不锈钢密度和硬度的增大，最佳烧结温度为1200℃左右。当青铜粉的体积分数为30％、烧结温度为1200℃时，316不锈钢的最大相对密度和硬度分别为95．1％和HRB83。添加青铜粉引起的液相烧结使不锈钢颗粒球形化趋势明显，颗粒表面平直化。     

静止进相器无功补偿原理及其仿真研究

介绍了一种由可控硅构成的交交变频器为主要结构的异步电动机静止进相器.讨论了静止进相器的原理、无功补偿特性及总体结构,并且对静止进相器对异步电动机定子电流的影响进行了仿真研究.     

调容式消弧线圈自动补偿系统的实现

介绍了我国电力系统配网谐振接地的现状及发展趋势,给出一种基于双CPU结构和晶闸管的调容式消弧线圈的工作原理。二次侧电容器组的分配原则,电容电流测量方法以及消弧线圈自动控制系统的构成, 介绍了本研究所构建的6 kV试验动模系统。试验结果表明:设计的方案和一次二次设备参数正确,动作准确快速     

星形接线并联补偿电容器的内部故障分析

电力电容器的故障分为内部故障和外部故障，本文以星形接线的三相电容器组为例。对电容器内部故障产生时电容器的相关电量加以分析。     

Structural evolution and stability of mechanically alloyed Fe-Ni nanocrystalline

The structural evolution and stability of Fe100-xNix(x=10, 20, 35, 50) alloys prepared by mechanical alloying were investigated through X-ray diffraction analysis and transmission electron microscopy. The intrinsic conditions of preparation determining phase stability in nanocrystalline were clarified. After being milled for 120 h, the powders of Fe90Ni10 and Fe80Ni20 consist of a single α(bcc) phase, Fe30Ni30 powders are a single γ(fcc), and for Fe65Ni35 powders there is co-existence of α and γ phases. The as-milled Fe80Ni20 powders annealed at 680 ℃ exhibits the stability of high-temperature γ phase at room temperature, which is consistent with the theoretical prediction.     

Solidification structures of high niobium containing TiAl alloys

To understand the effect of alloy stoichiometry on the microstructural development and mechanical behavior of γ-TiAlbased materials, it is necessary to have a determination of the phase relationships for the TiAl alloy system near the γ phase field.Cast structures and phases of Ti-(43-47)Al-8Nb-(1-2)Mn (at%) alloys have been studied by using scanning electron microscope and X-ray diffraction. Their solidification path and microstructure development during the solidification were analyzed. The experimental results show that the alloys with different Al contents form different macrostructures and microstructural morphologies. This indicates that the solidification paths are different with different Al contents. The alloy with 43Al forms equiaxed grain structure, and the solidification path is as follows: L → L β→β→α β→α β cores →α2 γ B2 cores. Whereas the alloy with 47Al forms columnar grain structure, and the solidification path is as follows: L → L β→α β L →α γ β cores →α2 γ B2 cores. The β phase is their primary solid phase and can be retained to ambient temperature. The alloy with 43Al solidifies completely into β phase. The peritectic reactions L β→α and L α→γ appear when the Al content increases to 47Al.