Synthesis of TiC by Self-propagating High-temperature Synthesis with Reduction Stage

Fine powder of TiC was prepared by self-propagating high-temperature synthesis(SHS)method with re-duction stage.The influence of diluent and relative density of the sample on both combustion rate and combus-tion temperature has been studied.The combustion reaction in the system of TiO_2-Mg-C begins at the meltingof Mg.The propagation of combustion wave is related to the gasifying of Mg.The activation energy of theprocess has an approximate linear dependence on the porosity of the sample.     

速动形状记忆合金元件设计原理

提出了评价速动双程形状记忆元件性能的主要参数,并说明了设计实用速动元件的原理和方法。     

Effect of heat treatment on the microstructure and hardness of C-Cr-W-Mo-V-RE Fe-based hardfacing layer

0IntroductionHot-rollers and scissors are the critical parts of thesteel rolling equipments.At present,the surface soften-ing,the early wearing and the tearing are the primary rea-sons for the lowservice life of the hot-rollers and scissors.Although hardfacing has been applied to repaire the partseasily being worn and torn,such as the hot-rollers and thescissors,and has been obtained economic benefits[1-3],this technology has common problem:if the hardfacing lay-er contains more excessive allo…     

Ni3Al中B和Mg的非平衡晶界共偏聚

在1023－1373K的初始温度和0.05-268.91K/s的冷速范围内，用Auger剖层分析确定含B和Mg的Ni3Al合金中B和Mg的非平衡晶界共偏聚行为，按照溶质－空位复合体迁移机制所导出的描述非平衡晶界偏聚的扩散速率方程解析表达式，很好地模拟了本实验结果，并确定了Ni3Al-B-Mg合金中B及B－空位复合体，Mg及Mg-空位复合体的扩散系数及复合体激活能。     

含杂环双季铵盐的合成及其缓蚀性能的研究

以甲硝唑为母体，以环氧氯丙烷为联接剂，合成了一种含有甲硝唑杂环的双季铵盐化合物.利用静态失重法、极化曲线、交流阻抗和扫描电子显微镜等方法对其在模拟油田水中的缓蚀性能进行了研究.结果表明，所合成的双季铵盐化合物易溶于水，并具有良好的缓蚀性能.      

铝合金牺牲阳极电流效率损耗的微观分析

探针（EPMA）和能谱分析技术(EDAX)，考察了铝合金牺牲阳极的显微结构和腐蚀后的边缘形貌，讨论了电流效率和显微组织之间的关系.结果表明：晶界腐蚀引起的晶粒脱落是铝合金牺牲阳极电流效率损耗的重要原因.      

EFFECT OF COMPOSITION ON HYDROGEN EMBRITTLEMENT IN Ni-Fe FCC ALLOYS

The ductility loss and threshold stress intensity,K_(IH)during hydrogen charging were measuredfor pure Ni and four Ni-Fe fcc alloys.The results show that ductility loss in 40Ni60Fe alloyand K_(IH)a 50Ni50Fe alloy have a minimum value.The variations of the amounts of hydride,hydrogen evolution and dislocation structure with composition have been investigated.The va-riation of hydrogen embrittlement susceptibility with composition measured by ductility lossand by K_(IH)or K_(IH)/K_C can be explained by means of the synthetical effects of amount ofhydride,solutionized hydrogen and the extent of dislocation planarity on hydrogenembrittlement susceptibility.     

高纯Fe中氢损伤规律的研究

本文采用正电子湮没技术研究了高纯Fe中的氢损伤规律,实验结果表明,在0.5mol/L H_2SO_4溶液中不加毒化剂电解充氢时,产生氢损伤的临界电流密度为20 mA/cm~2;而在0.5mol/L H_2SO_4溶液中加少量As_2O_3作为毒化剂电解充氢时,即使很小的电流密度也会产生氢损伤,配合慢拉伸试验,还发现试样内部产生氢损伤以后,它将控制随后的形变和断裂过程     

EFFECT OF ALLOY ELEMENTS ON QUASIEQUILIBRIUM MICROSTRUCTURE IN Fe-Mn-Ni-Cr STEELS

The microstructures of Fe-Mn-Ni-Cr steels with medium carbon and the effect of alloy ele-ments on them have been investigated by means of X-ray diffraction quantitative phase ana-lyses,metallography and hardness tests.The volume fraction of martensite in steels quenchedat 1100℃ can be expressed as:f_M~(1100)=162.643-15.482Mn-7.36Ni-4.286(Cr+Mo+V)Based on this expression,the quasi-equilibrium microstructure diagram has been obtained.Itis shown that the effect of Mn on the austenite stability is greater than that of Ni.The equiva-lent [Ni]=2.104Mn+Ni and equivalent [Cr]=Cr+Mo+V.The driving force for martensite transformation at M_s point has been calculated to hedrastically decreased by element Mn.     

(Ⅰ+Ⅱ)复合型氢致开裂的研究

本文研究了30CrMnSiA高强钢在纯Ⅰ型、纯Ⅱ型和(Ⅰ+Ⅱ)复合型加载条件下的氢致开裂。实验表明,在1NH_2SO_4溶液中预充氢的试件在上述加载条件下均表现出氢致脆性。纯Ⅱ型氢致开裂门槛值K_(ⅡH)/K_(ⅡX)=0.27,与纯Ⅰ型门槛值K_(ⅠH)/K_(ⅠX)=0.29基本相同,而在K_Ⅱ/K_Ⅰ比值为0.27,0.4和0.81时,(Ⅰ+Ⅱ)复合型氢致开裂门槛值分别为0.36,0.41和0.37,表明纯Ⅰ型和纯Ⅱ型具有更高的氢脆敏感性。最后用自Ⅰ型加载向Ⅱ型过渡时,三轴张力和塑性变形程度这二个矛盾因素对氢致开裂的共同作用解释了上述实验结果。