HEAT TREATMENT STRENGTHENING EFFECTS OF RARE EARTHS ON Mg—9Al ALLOY

Mg-9Al-xRE magnesium alloys were studied, where, x is 0, 0.4. 0.8. 1.2 and 1.6% (in weight percent, wt%), respectively. Influence of rare earths (RE) on microstructure and strength in both T4 (solute heat treatment) and T6 (solute heat treatment and artificial ageing treatment) were investigated. Strength of specimen was tested at ambient temperature. The micro structure was analyzed by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction analysis. RE additions improved T4 tensile strength of the treated alloys. Small addition (0.4wt%) of RE greatly improved the strength of ageing treated (T6) Mg-9Al alloy, but further additions caused decreasing.     

Flexible Furnace Concepts for Vacuum Heat Treatment Combined with High-pressure Gas Quenching

IN the past five years the process combination of vacuum hardening, respectively vacuum carburizing with high-pressure gas quenching was successfully introduced to the market, especially in the manufacture of gears. In the meantime furnace concepts for various applications are available to the industry. In the following report three plant varieties are introduced, which differ in process flexibility and throughput. This report also explains criteria for the selection of a furnace in view of the existing application requirements. Besides this a short introduction is given into the vacuum carburizing process and the high-pressure gas quenching technology.     

含共晶碳化物Fe—Cr—Mn合金在高温含硫气氛中的腐蚀研究

对含碳量为０．５０－２．６３％的Ｆｅ－Ｃｒ－Ｍ合金在８００℃下含硫混合气氛中进行腐蚀试验。用Ｘ射线物相分析法分析了腐蚀产物种类及其相对含量，观察测定了元素在腐蚀产物中的分布及试样亚表层共晶碳化物的腐蚀行为。     

车辆热交换器铝合金管的高频焊接

管材所用铝合金带料为三层复合材料,外层为Al-Si钎料层,中间为Al-Mn芯材,内层为Al-Zn防腐层。带材经成型机组成型后经高频焊接而成。研究表明:采用高频焊接铝合金管焊缝成形美观、无气孔等缺陷,焊速高,焊缝微观组织均匀,是一种理想的焊接工艺。     

齿轮激光热处理工艺试验与结果分析

提出了采用轴向分齿扫描法进行齿轮激光热处理的工艺，并对试验结果进行了理论分析，采用该工艺，可得到均匀的齿面硬度和较为理想的齿面硬化层分布状态，热处理变形小，可保证6－8级精度齿轮的原有精度等级，齿面可获得较大的残余压应力，有利于提高齿轮疲劳寿命。     

Effects of different metallurgical processing on microstructures and mechanical properties of inconel alloy 783

Different metallurgical processing, including the standard heat treatment, heat treatment without β aging, addition of high amount of Cr, and long-term isothermal exposure, was conducted on superalloy Inconel 783. For these processed materials, the tensile property and hardness at room temperature and stress relaxation behavior at 650 °C were examined. The testing results showed that isothermal exposure and heat treatment without β aging slightly enhanced the yield strength of alloy 783 at room temperature as well as all metallurgical processing in this study produced an identical stress relaxation behavior at 650 °C. The microstructure variation with different processing was analyzed using optical microscope, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).     

（V30Ti35Cr25Fe10）97．5Si2．5合金的结构与吸放氢性能

采用XRD，SEM和PCT测试研究了（V30Ti35Cr25Fe10）97.5Si2.5（at％）合金的组织结构与吸放氢性能。结果表明：合金由BCC相和C14 Laves相组成，BCC相含量为75％，晶胞参数为α=0．3021nm，Laves相含量为25％，晶胞参数为α=0．4920nm和c=0．7996nm。由于含有大量的Laves相，合金具有良好的活化性能，室温下不需孕育期就可以快速吸氢，5min内达到吸氢饱和状态，饱和吸氢量达到2．98％（质量分数，下同）。在一定氢压下，合金的容量可由合金中BCC相和Laves相的容量按组分的含量进行线性组合而成。     

先进超细化处理技术在钢铁材料中的应用

介绍了近年来钢铁材料在组织超细化处理技术方面的研究成果和各种超细化技术的适用范围，探讨了典型中碳低合金钢(Cr-Mo-V系)超细处理研究结果及性能变化，并为钢铁材料组织超细化技术的理论研究和实际应用提供参考。     

热处理对1Cr18Ni9Ti钢焊接接头性能的影响

试验研究了固溶＋稳定化处理、固溶处理和去应力退火处理对1Cr18Ni9Ti钢焊接接头力学性能的影响。结果表明：固溶＋稳定化处理试样的屈服强度、伸长率、抗拉强度均最高。扫描电镜观察结果表明：所有的断口均为韧窝型断裂。     

消除磨齿裂纹的工艺措施

介绍了磨齿裂纹的产生机理,给出了防止磨齿裂纹产生的工艺措施,收到了良好的效果。