LI Wei
钢铁研究学报(英文版)
A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron (Cr of 15%) is not high sometimes, but its cost is not low. Thus, medium CrSi wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ballonball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of medium CrSi cast iron are superior to those of martensitic high chromium cast iron (Cr of 15%). The main reasons are that (1) the stress in medium CrSi cast iron is released in the ascast state; (2) the matrix is fine pearlite with better toughness and plasticity; (3) the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; (4) high silicon content improves the morphology of eutectic carbide; (5) there is no secondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear.
关键词:
medium CrSi cast iron;microstructure;impact fatigue;impact wear
DING Hua
,
TANG ZhengYou
,
LI Wei
,
WANG Mei
,
SONG Dan
钢铁研究学报(英文版)
The mechanical properties and microstructure of two low carbon high manganese steels with 238% (No1) and 33% (No2) (mass percent) of manganese were investigated. The results showed that No1 steel possesses high strength and high plasticity, and No2 steel has a relatively high strength and extraordinary plasticity. The No1 steel exhibits both TRIP (transformation induced plasticity) and TWIP (twin induced plasticity) effects during the deformation; while only TWIP effect appeared under the same deformation condition for No.2 steel. The comparison between the microstructures and mechanical properties of two steels was made, and the strengthening mechanisms were also analyzed.
关键词:
manganese;TRIP;TWIP;microstructure;mechanical property
CHANG Ying
,
WANG Dapeng
,
LI Wei
,
PAN Wei
,
YU Xiaojun
,
QI Min
钢铁研究学报(英文版)
Rare earth permanent magnetic materials are typical electrical conductor, and their magnetic properties will decrease because of the eddy current effect, so it is difficult to keep them stable for a long enough time under a high frequency AC field. In the present study, as far as rare earth permanent magnets are concerned, for the first time, rare earth permanent magnets with strong electrical insulation and high magnetic performance have been obtained through experiments, and their properties are as follows: (1) Sm2TM17: Br=062 T, jHc=8037 kA/m, (BH)m=5897 kJ/m3, ρ=7 Ω·m; (2) NdFeB: Br=0485 T, jHc=76633 kA/m, (BH)m=3796 kJ/m3, ρ=9 Ω·m. The magnetic properties of Sm2TM17 and NdFeB are obviously higher than those of ferrite permanent magnet, and the electric insulating characteristics of Sm2TM17 and NdFeB applied have in fact been approximately the same as those of ferrite. Therefore, Sm2TM17 and NdFeB will possess the ability to take the place of ferrite under a certain high frequency AC electric field.
关键词:
Sm2TM17;NdFeB;electrical insulation;eddy current
ZHONG Shi-An
,
袁周率
,
LI Wei
,
乔蓉
,
TANG Chao-Fu
应用化学
doi:10.3969/j.issn.1000-0518.2008.08.027
采用分子印迹技术紫外光引发聚合方法制备了带支撑膜的铜离子印迹聚合膜.用扫描电子显微镜观察了膜的表面形态.膜渗透实验结果表明,通过对不同阳离子(如锌离子、钙离子等)的比较,此印迹膜对铜离子有较好的选择渗透性.分别考察了不同支撑膜、致孔剂和功能单体对膜结构及其渗透性能的影响,考察了pH值、阴离子及阳离子对膜渗透性能的的影响.结果表明,采用PVDF膜为支撑膜,乙酸铜为印迹离子合成的铜离子印迹膜,在pH值为1左右,阴离子为乙酸根离子时,对铜离子有较好的选择渗透性.
关键词:
分子印迹技术
,
印迹膜
,
膜渗透
,
铜离子
