流动粒子炉快速渗碳成功投产

流动粒子炉是一种新型的热处理设备,具有节电、效率高、质量好及安全等优点,属于全国1978～1980年十五项热处理新技术。应用流动粒子炉进行快速渗碳美国1976年已有报道。我国一机部将流动粒子炉化学热处理列为1978～1985年热处理技术科研项目。揭阳农机修理厂热处理班子1977年底试制成功25千瓦交流低压流动粒子炉。与同功率埋入式盐浴炉比较,升温速度提高一倍,节电45%。在这一基础上,从78年年底     

井式可控渗碳炉仿真工艺研究

可控气氛的热处理是当前运用最广也是最早应用计算机模拟技术的热处理技术,“动态碳热控制技术”的应用,对渗碳质量的精密控制显著效果。热处理车间从2002年引进Aichelin公司（爱协林）多用炉生产线,通过计算机辅助模拟设计软件的使用,可以做到渗碳工艺参数的优化、渗碳结果的预测、碳浓度分布的精确控制,从而获得理想的浓度分布和渗层组织。该软件还具有简单的程序设计菜单,友好的人机交流界面,为工程技术人员提供了一个良好的工艺设计平台。     

三相交流流动粒子电炉

一、流动粒子电炉在国内外试制概况流动粒子电炉是采用流态化原理建造起来的热处理加热炉。由于所采用的流态化粒子、气体种类、加热方式等不同,各国试制情况也有所不同。五十年代开始,美、英等国试制了外热式热源加热惰性粒子(石英砂、刚玉砂等)的流态化床炉子,炉温较低,在600℃以下。只能用于有色金属及合金的热处理(1)。     

缩短渗碳周期的操作方法

选用“渗碳-扩散”型渗碳工艺可以缩短生产周期,但在控制时间、滴量、炉压的操作上各家不尽相同,我们在长期实践中摸索出一种行之有效的方法,可使生产周期缩短1/4～1/3。一、渗碳排气结束后,由于钢表面含碳量极低,需要大量的活性碳原子。在这一阶段我们最大限度地提高碳势,使炉气碳势远远超过预定表层碳浓度,让钢     

轴承零件的控制气氛渗碳

在大型井式渗碳炉中,采用甲醇作载气,甲苯作富化气,对特大型轴承零件进行深层(渗层深度>2.5mm)渗碳。用氧探头测量氧势,以便调整、控制炉内渗碳气氛。新的渗碳工艺可使零件渗层的硬度梯度平缓,表层碳浓度达到有关标准的要求,并可取消传统的渗碳后高温扩散工艺。探讨了炉气中氧势、碳势与有效硬化层深度的关系。     

连续渗碳炉内工件表面状况对渗碳效果的影响

本文针对我厂后桥从动圆锥齿轮在连续炉内渗碳出现的渗碳层不均匀和表面碳浓度低的质量问题，进行了在渗碳前采用不同方法改善工件表面状况，以提高工件表面活化度的随产品的工艺试验，结果表明，高温烧洁脱脂后进行渗碳的效果最佳。     

流动粒子炉及其在轴承热处理上的应用

流动粒子炉即在炉膛内放有固态粒子(石墨粉、木炭粉或焦炭粉等物料层),以炉膛底部吹人压缩空气,使其固态粒子悬浮起来,类似于流体的“沸腾”状态,产生沸腾层,或叫做粒状物体的流态化。增加气流速度可使物粒层形成激烈紊流运动状态,因此使粒状物料具流动的特性(粘度小、可流动、保持水平、有浮力等)。将这种流动体加热就成为一种加热设备,即“流动粒子电炉”。这种设备如不加热,还是很好的冷却     

活塞销渗碳工艺的改进

活塞销是汽车发动机中连接活塞与连杆的重要零件。我厂过去采用低碳合金钢外表面渗碳淬火处理,渗碳剂单纯使用煤油,造成碳黑严重、硬度不均、质量不稳。从去年起,我厂大胆采用复合渗碳剂,把单液渗碳改为多液渗碳、较好地解快了渗碳质量问题。现将具体作法介绍如下: 先将活塞销按批号、炉次分类装夹在专用工具上待渗碳。使用75千瓦井式气体炉进行加热、渗碳温度为910℃。当炉温升至800℃时,便可向炉内滴入甲醇(40滴/分)。炉温达到910℃时保温20～     

浅谈低压真空渗碳热处理技术

本文探讨了低压真空渗碳原理及炉气成分,以及低压真空渗碳的优势与不足,影响零件表面碳浓度的相关因素。结合实际应用情况,确定了几种典型齿轮渗碳工艺程序,为航空产品研制生产作好了技术准备。     

易普森AvaC乙炔低压渗碳工艺设备及其工业应用（上）

1.前言 低压渗碳或真空渗碳,已大致在工业上应用了20多年,基本上是采用丙烷气作为渗碳介质。 但是用丙烷作为渗碳介质进行低压渗碳时存在诸多问题,如:炉内碳黑、炉内壁和真空管道上产生的焦油以及难以对密集装料或复杂几何形状工件进行均匀渗碳等,致使低压渗碳或真空渗     

做平面运动滚子从动件盘形凸轮机构第Ⅱ类综合问题的广义化研究

提出了“狭义、广义第Ⅱ类机构综合问题”的概念;通过建立预备公式、引入“旋浮数轴”概念等,对于一维情形,提出“瞬时/整程区间套”的求解原理和区间套存在性(态)的判定方法,并求解其“劣解/非劣解区间套”和“区间最优解”;对于二维情形,提出“有解区间套”、“整程区域套/机构解全域”的求解原理和区域套存在性(态)的判定方法,并求解其“劣解/非劣解区域套”和“全域最优解”等;基于Visual Basic6.0软件开发了具有可视化、规律发掘功能的通用软件CALRFCY,从而解决了“广义第Ⅱ类机构综合”解的存在性(态)判定及其求解方法的问题。通过两个机构综合实例论证了偏置式机构较正置式机构具有“你无我有,你有我优”的固有潜质和显著优越性。     

Formation of Lubricant “Sierra” at Boundary Between Perfluoropolyether Solution Dipped and Undipped Zones over Diamond Like Carbon Coated Magnetic Disks

An unstable phenomenon arising at the boundary between perfluoropolyether (PFPE) solution dipped and undipped zones over diamond like carbon (DLC) coated magnetic disks was studied. The formation conditions of a ridge of lubricant, or “sierra,” at this boundary and the structure of the “sierra” were clarified. It was found that the “sierra” structure of the lubricant suddenly formed when withdrawing the disk from the lubricant solution was decreased to less than a specified value of around 1 mm/s. The “sierra” was less likely to form for a lower lubricant concentration and a longer elapsed time after making the lubricant solution. It was also revealed that, along the ridgeline of the “sierra,” peaks formed periodically and the peak feet propagated in the direction perpendicular to the boundary, forming convex fronts and leaving multiplex bead chains of lubricant accumulations inside the convex.     

基于“麦可思”年度调查报告的专业调控方案设计

根据麦可思对无锡工艺职业技术学院应用电子技术专业2009到2011三届年度报告关键数据中“毕业半年后的就业率”、“毕业半年后收入”、“对口就业率”、“毕业生对母校满意的人数”、“考生选择本专业首要理由的人数百分比分布”和“愿意推荐母校的人数”,分析“核心知识基本工作能力方面”、“对口就业方面”和“主要课程学习方面”存在的问题：由此提出了加强校企交流合作．构建标准化专业建设框架和提升实践教学等方面的调控措施。     

The Isothermal Lubrication of Cylinders

When the hydrodynamic problem of cylinder lubrication is considered, two distinct types of solution emerge. For light loads the cylinders retain their unloaded geometry; the Martin solution for this condition is well known. When the contact forces are large, significant elastic deformation may occur; the resulting elastohydrodynamic regime has been extensively analyzed in recent years.

Equations are now available for the calculation of minimum film thickness in the “rigid” and “elastic” situations. In this paper computing methods appropriate to each range of conditions are summarized, and the nature of the solutions is considered in some detail. In particular the valid range of application of the “rigid” and “elastic” film thickness relationships is discussed. An intermediate range of conditions between the “rigid” and “elastic” regimes is defined.

Finally, a chart is presented to enable a particular problem to be located in the “rigid,” “intermediate,” or “elastic” zones.     

Microscopic analysis of “iron spot” on blue‐and‐white porcelain from Jingdezhen imperial kiln in early Ming dynasty (14th–15th century)

“Sumali,” as an imported cobalt ore from overseas, was a sort of precious and valuable pigment used for imperial kilns only, which produces characteristic “iron spot” to blue‐and‐white porcelain in early Ming Dynasty (A.D. 14th–15th century). Although there were some old studies on it, the morphology and formation of iron spot has not been fully investigated and understood. Therefore, five selected samples with typical spot from Jingdezhen imperial kiln in Ming Yongle periods (A.D. 1403–1424) were analyzed by various microscopic analysis including 3D digital microscope, SEM‐EDS and EPMA. According to SEM images, samples can be divided into three groups: un‐reflected “iron spot” without crystals, un‐reflected “iron spot” with crystals and reflected “iron spot” with crystals. Furthermore, 3D micro‐images revealed that “iron spots” separate out dendritic or snow‐shaped crystals of iron only on and parallel to the surface of glaze for which “iron spot” show strong metallic luster. Combining with microscopic observation and microanalysis on crystallization and non‐crystallization areas, it indicates that firing oxygen concentration is the ultimate causation of forming reflective iron spot which has a shallower distribution below the surface and limits crystals growing down. More details about characters of “iron spot” used “Sumali” were found and provided new clues to coloration, formation mechanism and porcelain producing technology of imperial kiln from 14th to 15th centuries of China.     

乘用车变速器动态换挡性能提升的改进策略

随着乘用车日趋饱和,传统的手动变速器正向“精品化”“高扭矩”“轻量化”方向发展。动态换挡性能作为手动变速器感知属性受到越来越多的关注。针对动态换挡性能4种主观测评问题——“力重”、手感“偏硬”、“二次冲击”、“尾端阻滞”提出对应的改进策略,并采用GSA客观测试方法验证了改进策略的合理性和有效性。     

Anisotrpic friction behavior of charcoal and the influence of humidity

Tribo-tests were carried out on pyrolyted wood derived charcoal specimen in the directions of “flat-face” and “curved-face”. In former direction, an ultra-low friction coefficient 0.03 was measured in a high humid condition with 75% relative humidity. Eventually, the friction coefficient becomes 0.45 when the humidity level decreased to 10%. However, under similar tribo-test condition, the friction coefficient is high 0.1 in the “curved-face” of charcoal specimen at 75% humidity. This value further increased to 0.8 at humidity level of 10%. Large amount of polar functional groups, oxygen complexes and water molecules was observed on the “flat-face” due to the presence of microscopic pores which act as a reservoir to lubricate the sliding surfaces.     

Table Tennis: Preliminary Displacement in Pimples-Out Rubber

Following the recent trend of applying a more scientific approach to the study of all aspects of racket sports, we have developed a simple tribological method allowing to characterize unequivocally and unbiased by human factor the frictional behavior of table tennis rubber racket covering. This technique suggests examining the performance of rubber coverings at the onset of sliding against the table tennis ball by using three non-dimensional parameters, “friction,” “stickiness,” and “grip.” However, while “friction” and “stickiness” parameters were elaborated well, the “grip” parameter was only outlined due to the lack of actual determination of preliminary displacement on which it is based. To fill this gap, here we focus on studying preliminary displacement in four short and four long pimples-out rubbers. It is also found that a particular attention should be paid for the environmental conditions under which the three parameters are determined.     

行星式链-连杆组合机构的优化综合

本文首次提出了设计具有最佳传动角的行星式链-连杆组合机构应满足的条件,并以“链长运动循环”为基础,给出了“输入周期角”、“输出周期角（步进角）”、“步进次数”、“停歇角”和“停歇时间比”等运动参数的定义。本文对该机构进行了优化综合,该优化综合方法不仅适用于上述的情况,而且也适用于输出杆的其他运动或设计要求,只需相应地修改或增减分目标函数和约束条件即可。     

削匀机刀辊切削过程中的“跳刀”和“让刀”的研究

本文针对在皮革削匀切削过程中“跳刀”和“让刀”缺陷的产生机理进行了研究,认为发生“跳刀”和“让刀”是由于螺旋刀片的切割作用不强、推挤压作用过大而造成的,进而提出了增加刀片前角,减小刀片螺旋导角、以减小刀片的结构锋角和工作锋角来增强刀片的切割作用,解决了“跳刀”和“让刀”问题。通过理论探讨,给出了前角和刀片螺旋导角的最佳取值范围。