φ100mm穿孔机机架的有限元分析

本文用数值计算方法,对φ100mm二辊穿孔机在轧制状态下的应力和应变进行了计算。为今后二辊穿孔机的设计和制造提供了依据,同时对全国众多的φ100mm二辊穿孔机组的挖潜改造,亦具有实用的参考价值。     

基于MATLAB锥形辊穿孔机开度值的计算与分析

为实现高精度钢管的轧制,必须计算变形区中轧辊的开度值。介绍一种基于MATLAB软件计算锥形辊穿孔机开度值的数学模型,对锥形辊穿孔机的开度进行了定量分析。此方法可应用于锥形辊穿孔机的顶头设计,也可作为锥形辊穿孔机工艺调整的依据。     

高温合金圆坯穿孔时力和变形参数的测定

φ30mm二辊斜轧穿孔机使用高温合金圆坯穿孔,在不同加热温度、轧辊转速、辊面角和前进角条件下,测定了轧辊入口锥和出口锥轧制力、顶头的轴向力、穿孔时间和坯料扭转变形程度。     

下压轧制的斜轧穿孔轧辊开度分析

斜轧穿孔机轧辊开度计算是轧机工具设计和调整参数计算的基础。文中分析了下压轧制条件下二辊斜轧穿孔机的轧辊开度,并讨论了轧辊开度的非对称性对穿孔过程及毛管壁厚均匀性的影响。     

管坯穿孔工艺技术(Ⅱ)——《热轧无缝钢管实用技术》

正3二辊斜轧穿孔机的工艺参数设计与调整二辊斜轧穿孔机的工艺参数设计与调整的目标是:管坯咬入平稳,穿孔过程稳定,顶杆无明显抖动,抛钢顺利;毛管尺寸合格、壁厚均匀、内外表面质量良好;穿孔机主传动电机负荷正常。二辊斜轧穿孔机工艺参数的调整主要包括:轧制中心线、轧辊间距、椭圆度系数、顶伸量、喂入角、辗轧角、扩径量、抱辊位置、轧辊转速、导盘速度和导盘位置等。3.1轧制中心线调整     

异径四辊孔型轧制力参数的试验研究

1.前言四辊组合孔型轧制是一种新型的精密异型材生产方法。由于其具有一系列优点,近年来在国内外受到重视。文献曾对同径四辊孔型轧制力参数进行过研究,但对异径四辊孔型轧制力参数的研究很少。本文对异径二主二从四辊孔型轧制的水平辊、立辊轧制力和水平辊单位压力进行了实测,并对其结果产生的原因进行了分析。     

浅谈锥形辊穿孔机轧辊的设计

根据穿孔机工具中的轧辊的设计特点,系统地探讨了锥形辊穿孔机的轧辊参数设计原则,分析主要参数的计算公式和设计中应注意的问题。分析认为:科学合理地设计锥形辊穿孔机轧辊,可以使减径量最小,却不影响咬入,对穿孔工序极为有利;此外,还能减少轧制缺陷,尤其在生产难轧钢种时,其优势更明显。设计合理的锥形辊穿孔机可以提高产品质量、降低轧制能耗和工具消耗。     

新型穿孔机的发展及应用

本文介绍了六十年代中期以来科技工作者所提出并完善了的新型穿孔机的工艺和设备结构。七十年代以来,世界许多国家建设无缝钢管轧机一般都选择三辊穿孔机、大导盘二辊立式穿孔机、推轧穿孔机或双支承菌式穿孔机。这些新型穿孔机各有特点,许多国家在应用中继续试验研究,不断改革,使之完善。文章还对建设新钢管轧机时如何选择穿孔机的问题提出了看法。     

下压轧制的斜轧穿孔非对称轧辊开度的补偿

下压轧制条件下二辊斜轧穿孔机存在轧辊开度非对称问题。为补偿非对称开度对穿孔过程的不良影响，本文提出了一种工具锥角设计思想和锥角优化计算方法，以改善穿孔毛管的横向壁厚均匀性。     

热轧地下卷取机牌坊式转向夹送辊设计

在热轧地下卷取机牌坊式转向夹送辊设计过程中,针对下夹送辊的辊径大小、上辊压下力大小难确定的问题,本文参照热轧卷筒最小直径的计算方法,确定下辊的最小直径;把带钢的夹送过程假设成轧制过程和弯曲过程的合成,按轧制理论计算的轧制力其值等于夹紧力值;把带钢弯曲简化成悬臂梁,并用矫直弹塑性理论进行建模,计算的上辊弯曲力值等于压下力值,并用实例验证上辊压下力大小的合理性。     

Prospects of the Use of Synergetic Approach to Solution of Problems of the Science of Nanomaterials

A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.     

Kinetics of the oxidation of metals — Influence of self-diffusion of metal

The importance of the self-diffusion of a metal during its oxidation by a gas is treated for the cases of nonstoichiometric oxides having either interstitial cation or cation vacancies. We have established a general relationship for the reaction rate when a mixed diffusion process occurs. From this relationship, we have shown that the pressure dependence can be different, according to whether the rate-determining process is the self-diffusion through the metal or through the product.     

胫骨生物陶瓷复合材料的微结构增韧机理

扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性.     

面向零件形状的计算机图形库的开发

论述了CAD技术中参数化设计的三种建模方法，重点介绍了基于特征的参数化建模原理。在此基础上，分析机械设计中的机构结构，归纳出其零件的几何特征构成。设计了机构CAD图形库，并提出了该图形库生成步骤和人机交互界面。     

FeCrAIW电弧喷涂层组织的致密化研究

采用激光辐照对FeCrAlW电弧喷涂层的组织进行致密化处理,借助扫描电镜和X衍射对涂层的组织进行了分析.测试了涂层的显微硬度.结果表明:涂层组织致密度提高,孔隙率明显降低.随着激光扫描速度的增加,涂层的显微硬度降低.在较低的扫描速度下,涂层与基体之间形成互熔区,涂层与基体之间产生良好的冶金结合.     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.     

Ab-initio calculation of enthalpies of formation of intermetallic compounds and enthalpies of mixing of solid solutions

A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described.