真空化学热处理多用炉的研究

A new type of versatile vacuum electric furnace for chemical heat treatment is developed, in which the low vacuum structure heating outside, the NH_3 auto-disintegrating instrument, the technology of ultra-red heating, TTL automation and the diverse distr     

Formation of Zinc Oxide in the Course of Directed Nitriding With Aluminum Zinc Alloy

ZnO is formed in the course of directed nitriding with Al-Zn alloy, and that the effect of zinc and magnesium on the directed nitriding process is big different. The long fibers which diameter are far less than one micrometer, short bar-like and tetrapod-like zinc oxide is obtained. The three important stages of initial growth kinetic of ZnO approving ZnO have growth mechanism of VS, they are stage of accelerating, linear and parabola, are discovered. Experimental results show that the volatilization of zinc play a very important role in the growth of ZnO,the growth of ZnO is controlled by the diffusion of zinc in the Al-Zn alloy , and the morphologies of ZnO is depend on the saturation level of the vapour.     

履带摩擦副的失效分析研究

In this paper, the condition of service and employ request of rubbing piece formed by tank catepillar pin and tank caterpillar plank, the coordination of tank caterpillar pin strength, tenacity and capacity against rubbing away, the materials used in the     

TEM INVESTIGATION ON AGED ION-NITRIDING LAYER OF PURE IRON

The phase transformation in the diffusion layer after slow cooling and aging of pure iron ion -nitrided was investigated with TEM. Refering to principle of Moire method measuring macroscopical strain, the values of coherent strain at interfaces between a" and aN phases were determined by means of TEM analyses.     

Plasma Nitriding of En40B Steel with the Incorporation of Pure Rare Earth La, Ce and Nd

Pure rare earth metal block La, Ce and Nd was put into the nitrided furnace respectively as a sputter source when typical nitride steel En40B was plasma nitrided. It was found that the incorporation of pure rare earth resulted in the changing of characteristic of glow discharge. Analysis of samples after treatment was performed using related instruments and facilities to examine the effects of treatment on microstructure, micro hardness and element distribution. The results showed that the incorporation of rare earth metals in the glow discharge influenced the diffusion of nitrogen in some degree. Thus the difference of distribution of elements, structure and hardness in the nitrided layer was formed compared with the conventional be plasma nitrided. These significantly affected the response of the investigated steel on plasma nitriding. The extent of influence to plasma nitriding varied with different rare earth.     

辉光离子氮化可锻铸铁耐磨性能的研究

可锻铸铁因其具有良好的强度、塑性和冲击韧性而广泛用来制造曲轴、凸轮轴、活塞环、连杆等机械零件,但由于这些零件的破坏方式大部分是由于表面层过度磨损所造成,故研究可锻铸铁的磨损机制,找到提高其表面层的耐磨性能的方法十分必要。本文通过对辉光离子氮化处理前后的可锻铸铁滑动(干燥条件下和润滑条件下)磨损实验,探讨了摩擦压力、摩擦速度,润滑条件等因素对磨损性能的影响。同时,说明了辉光离子氮化方法对提高其表面层耐磨性能的作用和效果。     

提高坦克履带销使用寿命的研究

本文对坦克履带销的失效形式进行了分析研究后,在不改变履带销用钢及技术要求条件下,对热处理工艺进行了优化设计,采用了非常规碳氮复合渗热处理新工艺,使履带销的使用寿命由原来的150-200摩托小时提高到600摩托小时以上,取得明显的军事和经济效益.     

塑机螺杆高效渗氮工艺研究

采用二段三循环法对38Cr Mo Al A料筒螺杆进行表面氮化改性处理,经35h渗氮处理后,渗氮层深度超过0.55mm,表面硬度大于HV900,表面氮化脆度为一级。该结果表明二段三循环法可以比常规的二段渗氮法减少时间40%左右。     

高温快速盐浴渗氮提高拖拉机曲轴性能

为提高拖拉机曲轴盐浴渗氮效率,选择用于生产拖拉机曲轴的常用材料45钢,分别进行不同保温时间的高温快速盐浴渗氮和常规盐浴渗氮。利用光学显微镜、X射线衍射仪、显微硬度计和电化学工作站对渗层的显微组织、物相、硬度和耐蚀性进行了测试和分析。研究结果表明:经过660℃×20 min高温盐浴渗氮处理后化合物层的厚度与560℃×140 min常规盐浴渗氮相近,表明高温盐浴渗氮可以显著缩短渗氮的时间。在化合物层厚度相近的情况下,高温盐浴渗氮处理后渗层中γ'-Fe4N相含量从常规盐浴渗氮的0.46增加到0.61,同时,截面最高硬度从常规盐浴渗氮的702提高到784 HV0.01,并且耐蚀性能也获得了提高。该研究可为提升盐浴渗氮技术应用于45钢拖拉机曲轴表面改性工艺方案提供参考。