ZHANG Yue
,
CHU Wuyang
,
XIAO Jimei(Department of Materials Physics
,
University of Science and Technology Beijing
,
Beijing 100083
,
China) OUYANG Shixi
,
YUAN Runzhang(State Key Laboratory for Synthesis and Processing of Advanced Materials.Wuhan University of Technology
,
Wuhan 430070
,
China)
金属学报(英文版)
For alloy Ti-24Al-11Nb,stress corrosion cracking(SCC) in methanol solution and hydrogen induced cracking(HIC) during dynamic charging at room temperature have been studied.Experiment has shown that the normalised threshold stress intensities of SCC failure for various microstructures are KISCC/KC =0.53 0.69 and the threshold value for SCC arresting KISCC/ KIC=0.61-0.79.The threshold values of HIC during dynamic charging are close to that of SCC,but da/dt or fracture time of HIC is one to three orders of magnitude smaller or longer than that of SCC,respectively.The.fracture surface for HIC is also different from that for SCC.For the Ti-24Al-Nb alloy-methanol systein,a kind of inierphase SCC has been found For the microstructures resulting from furnace cooling,SCC initiated and propagated preferentially along theα2/βinterphase boundaries,displaying the microstructure on the fracture surface of SCC.However,there is no interphase SCC for the microstructure resulting from air cooling.
关键词:
:Ti-24Al-11Nb
,
null
,
null
,
null
刘军恒
,
姚春德
,
魏立江
,
耿鹏
,
王全刚
,
余海涛
工程热物理学报
在六缸电控单体泵增压中冷重型柴油机进气管上面布置电控甲醇喷嘴,采用柴油引燃甲醇均质混合气的二元燃料燃烧模式,开展了高甲醇柴油比的二元燃料燃烧特性与排放特性试验研究.研究结果表明:随着醇柴比的增加,二元燃料的滞燃期增加,放热率峰值、最大缸内压力和压力升高率峰值都变大;未燃HC和CO排放上升,NOx排放则先下降后上升;烟度与颗粒物浓度排放都下降,低负荷下醇柴比为4.0时效果尤其显著;大负荷时二元燃料燃烧时热效率明显提高.
关键词:
柴油机
,
甲醇
,
二元燃料
,
燃烧
,
排放
涂维峰
,
冉景煜
,
张力
工程热物理学报
在严格的动力学控制下研究了甲醇催化燃烧反应动力学本征特性.铂催化剂上甲醇催化燃烧由氧气在催化剂上的活化过程控制,催化燃烧速率受限于铂表面的活性氧原子浓度;甲醇催化燃烧速率等于氧气在催化剂表面上的活化速率,随氧气分压增加而线性增加而不依赖于甲醇的分压.催化燃烧反应速率常数随催化剂颗粒直径减小而降低,随铂原子配位数减小而降低,由于少部分活性组分更容易吸附在铂催化中低配位数的原子上限制了氧气的活化过程.在微量催化剂的协助下甲醇就能实现稳定的低温催化燃烧,因而能有效地改善微细燃烧器内燃烧特性.
关键词:
催化燃烧
,
甲醇
,
氧气活化
,
颗粒直径
,
动力学本征
