Y.S.Wu
,
D.Y. Liu
,
B. Cao
,
F. L. Wang
,
X.Y. Wang
,
Z.Fang and Z.G.Du (Department of Surface Science and Corrosion Engineering
,
University of Science and Technology Beijing
,
Beijing 100083
,
China)
金属学报(英文版)
The electrochemical behaviour, including free corrosion potential, free corrosion current density and polarization curve, of various thermal history zones on the weldment was measured in this paper. The weldment consisted of matrix, tempering zone. incomplete normalized zone, normalized zone, overtemperature zone, fusion line zone and weld metal zone. The electrochemical behaviour of the ferrite, pearlite and mixed structure in various zones have successfully measured. The results showed that there was a difference of free corrosion potential which is smaller than ca. 200mV between various zones and about 20-150mV potential difference between ferrite and pearlite in every zone. The free cormsion potential of fusion line zone was the most negative between various zones. The free corrosion potential of pearlite was some dozens mV more negative than ferrite. The corrosion course of various zones and of different phase structures on the weldment and their effect on corrosion attack of weldment were discussed.
关键词:
weldment
,
null
,
null
,
null
L.Y. Dai
,
B. Cao
,
M. Zhu
金属学报(英文版)
The cryogenic milling and milling in conjunction with dielectric barrier discharge plasma (DBDP) have been separately set up. The combined effect of low temperature and plasma on ball milling has been investigated by examining the refinement of particle size and grain size of iron powder using scanning electron microscopy, X-ray diffraction, and small angle X-ray scattering. It was found that the mean size of iron particles could reach 104nm only after 10 hours of ball milling in conjunction with DBDP, whereas a minimum average grain size of 8.4nm was obtained by cryomilling at －20℃; however, it is difficult to refine the particle size and grain size under the same milling condition in the absence of DBDP and cryogenic temperature.
关键词:
ball milling
,
null
,
null
赵定国 郭培民
钢铁研究学报
根据CaO-SiO2、CaO-B2O3和SiO2-B2O3二元相图确定了熔渣的结构单元，利用熔渣的分子离子共存理论建立了CaO-SiO2-B2O3三元熔渣活度模型。通过对模型求解，可以计算出熔渣中CaO﹑SiO2﹑B2O3﹑CS、C2S、C3B、C2B、CB和CB2的组分活度。分析了熔渣碱度、B2O3含量及温度对熔渣组分活度的影响，其中熔渣碱度的影响最大，B2O3含量的影响次之，温度的影响最小。
关键词:
熔渣;共存理论;活度;计算模型
赵定国
,
郭培民
,
赵沛
钢铁研究学报
根据CaO-SiO2、CaO-B2O3和SiO2-B2O3二元相图确定了熔渣的结构单元,利用熔渣的分子离子共存理论建立了CaO-SiO2-B2O3三元熔渣活度模型.通过对模型求解,可以计算出熔渣中CaO、SiO2、B2O3、CS、C2S、C3B、C2B、CB和CB2的组分活度.分析了熔渣碱度、B2O3含量及温度对熔渣组分活度的影响,其中熔渣碱度的影响最大,B2O3含量的影响次之,温度的影响最小.
关键词:
熔渣
,
共存理论
,
活度
,
计算模型
WANG Hongming
,
LI Guirong
,
LI Bo
,
et al
钢铁研究学报(英文版)
B2O3 is selected as fluxing agent of CaO-based ladle refining slag to decrease the melting temperature as well as to improve the speed of slag forming and the refining efficiency. The effects of B2O3 on the melting temperature of two series of refining slags including the low basicity slags (the mass ratio of CaO/SiO2 is 3~4) and the high basicity slags (the mass ratio of CaO/SiO2 is 5~8.75) were investigated. The slag melting temperature was measured using the hemisphere method. The results indicate that the fluxing action of B2O3 is better than that of CaF2 and Al2O3. For the CaO-based refining slag with low basicity, the melting temperature is decreased effectively when B2O3 is used to substitute for equal mass of CaF2, Al2O3 and SiO2, respectively. For the CaO-based refining slag with high basicity, when CaF2 is substituted with B2O3, the melting temperature can be decreased remarkably. Especially, when the mass ratios of CaO/Al2O3 and CaO/SiO2 are in range of 1.1~4.0 and 5.25~8.0, respectively, the slag melting temperature is lower than 1300℃. Therefore, the B2O3-containing refining slags with high ratios of CaO/Al2O3 and CaO/SiO2 have ultralow melting temperature. As a result, not only the slag forming speed but also the capabilities of desulfurizing, dephosphorizing and absorbing deoxidation products are expected to be improved.
关键词:
Fluoride-free slag;Boron oxide;CaO-based refining slag;Melting temperature;Basicity
Journal of Alloys and Compounds
The subsolidus phase relations of the system La2O3-CaO-B2O3 are investigated by means of X-ray diffraction (XRD) analyses. There are seven binary compounds and five ternary compounds in this system. The phase diagram comprises eighteen three-phase regions. A new ternary compound Ca4LaO(BO3)(3) (CLOB) is identified. It has a monoclinic structure with cell parameters a=8.1732(1) Angstrom, b=16.0860(3) Angstrom, c=3.6268(1) Angstrom, beta =101.40(1)degrees and space group Cm. At low temperature, the XRD patterns of the CLOB compound indicate that a phase transition in the low temperature range is absent. The expansion coefficients in the three major directions are different, the value of alpha (c) being the largest. (C) 2001 Elsevier Science B.V. All rights reserved.
关键词:
optical materials;oxide materials;X-ray diffraction;crystal;structure;phase diagram;crystal
Journal of Alloys and Compounds
The subsolidus phase relations of the system Y(2)O(3) -CaO-B(2)O(3) are investigated by means of X-ray diffraction (XRD) analyses. There are six binary compounds and three ternary compounds in this system. The phase diagram comprises 13 three-phase regions. The ternary compound CaYBO(4) is refined from powder XRD data by the Rietveld method. It has a warwickite-like structure with cell parameters a=10.4354(3) Angstrom, b=9.6126(2) Angstrom, c=3.5880(1) Angstrom and space group Nam. The rationality of the CaYBO(4) structure is examined by Brown bond valence model and IR spectra. (C) 2001 Elsevier Science BY. All rights reserved.
关键词:
oxide materials;crystal structure;X-ray diffraction;phase diagram;crystal-structure
吕安国
,
丘泰
,
刘敏
,
周洪庆
,
王美娜
硅酸盐通报
doi:10.3969/j.issn.1001-1625.2006.05.011
在CaO-B2O3-SiO2玻璃粉末中,通过添加助烧剂制备了CaO-B2O3-SiO2(CBS)玻璃陶瓷材料.研究了助烧剂P2O5和ZnO的助烧作用、材料的介电性能和相组成、显微结构.分析认为,P2O5能促进低熔点玻璃相的形成,ZnO则可以提高玻璃相的粘度,扩大烧结温度范围,并防止试样变形,复合添加P2O5和ZnO可成功烧结CBS玻璃粉末;在CBS玻璃陶瓷材料中,包含有β-CaSiO3、α-SiO2和CaB2O4三种晶相,晶粒发育均匀,粒径分布较合理,大小为0.5μm左右;添加质量分数为2%的P2O5和0.5%的ZnO作烧结助剂,可制备10MHz下,εr为6.38,tanδ小于0.002的玻璃陶瓷材料;烧结温度低于900℃,可实现银、铜电极共烧,可用作LTCC材料.
关键词:
CBS玻璃陶瓷
,
助烧剂
,
低温烧结
,
介电性能
石鹏途
,
舒万艮
,
于健
,
吕兴栋
稀土
doi:10.3969/j.issn.1004-0277.2005.06.003
用常规的高温合成法合成了CaO-SiO2-B2O3-Sm2O3玻璃,探讨了玻璃的最佳合成温度、玻璃的吸收光谱并研究了其发光性质.在CaO-SiO2-B2O3-Sm2O3玻璃体系中观察到了Sm3+的发射光谱.样品的发射光谱有三个主要荧光发射峰, 峰值波长分别为568nm、605nm、650nm, 其中最强峰为605nm, 这些荧光峰均为线状峰,可见发射起源于Sm3+ 4f电子的f-f跃迁.其中568nm对应于4G5/2→6H5/2跃迁、605nm对应于4G5/2→6H7/2跃迁、650nm对应于4G5/2→6H9/2跃迁,光谱性质表明这种玻璃体系能够把太阳光中的紫外光转换成红光,从而增强红光的发射强度.可以利用这些玻璃的发光性质来制备农用转光玻璃.
关键词:
发光性质
,
稀土激活玻璃
,
转光
