QIN Zuoxiang
,
ZHANG Yansheng
,
ZHU Naiping Department of Materials Engineering
,
Dalian Railway Institute
,
Dalian
,
116022
,
China.Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China.
材料科学技术（英文）
The oxygen relief/absorption,superconduc— tivity and structure of(Bi_(1-x)Pb_x)_2Sr_2Ca_2— Cu_3O_y compounds have been studied by TGA, electrical resistance measurement and X-ray diffraction.The amount of oxygen which can be re- leased and superconductivity of the compounds are correlative to Pb content.The release of oxygen in- creases when x less than 0.2 and decreases when x exceeds 0.2 with increasing x.The appropriate con- tent of Pb for superconductivity is in the range of 0.1
关键词:
oxygen relief/absorption
,
null
,
null
,
null
GONG Hai
,
ZHANG Xiumu Department of Materials
,
Dalian Railway Institute
,
Dalian
,
116022 China.Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China.
材料科学技术（英文）
The morphology and substructure of mixed martensites in ferrous alloys have been examined by using optical and transmission electron microscope. The results indicated that the main formation se- quence of martensitic morphology was butterfly→ plate→lath,with decreasing forming temperatures when the plastic accommodation takes place in the parent phase,which is affected by the transforma- tion strain fiélds.It was shown that the martensite morphology is not only decided by the forming temperature alone,but also by the dislocation struc- ture in austenite before the transformation.
关键词:
martensite morphology
,
null
,
null
Z.M. Ding1)
,
Y. Lei2) and L.J. Lao1) 1)Department of Materials Engineering
,
Dalian Railway Institute
,
China 2)Department of Materials Science & Engineering
,
Dalian University of Technology
,
China
金属学报(英文版)
Theacicular austeniteformation process duringintercritical annealing atslow heating speedof0 5 ℃/ min isinvestigated using TEMin the sample of 30 CrMnSiA. The resultsshow thatinthe preliminarystage, austenitesnucleateintheform ofshortneedle atshort rod like cementites, which hasthesame orientation and precipitates along the boundary of original martensitelathes. Asthetemperatureincreasingslowly, the austenites grow up and connect witheach other alongtheboundaryoftheoriginallathesso astoform acicular austenite. At last,the fully grown austenite connectsin the direction verticalto the boundary of lathes, leavingthe remnant ferrites appear in the shape of rhombus, the original austenite grainshaperecovers and the feature of thethick lath remains. The superledgeinterface has been found and someaustenitegrowsintoferritein theshapeoflath.
关键词:
austenitictransformation
,
null
,
null
CUI Juan
,
LIU Yazheng
,
PAN Hui
,
GAO Lifeng
钢铁研究学报(英文版)
The microsturctural transformation of austenite grain, pearlite interlamellar spacing, and lamellar cementite thickness of spring steel 60Si2MnA for railway were studied in the hotrolled and reheated states. Furthermore, the effect of microstructural characterization on its final mechanical properties was discussed. The results showed that as far as 60Si2MnA, the pearlite interlamellar spacing determined the hardness, whereas, the austenite grain determined the toughness. Compared with microstructure and mechanical properties in the hotrolled state, after reheating treatment at 950 ℃, its average grain sizes are apparently fine and the pearlite interlamellar spacing and lamellar cementite thickness coarsen to some extent, but both hardness and impact toughness increase to HRC 48 and 85 J, respectively. In the course of making spring, the optimum reheating austenitizing temperature for the 60Si2MnA steel is 950 ℃.
关键词:
austenitizing temperature;austenite grain;pearlite interlamellar spacing;hardness;toughness
B.W. Wang
,
H. Shen
金属学报(英文版)
Ni-Cr System solar selective thin solid films were prepared by d.c. magnetron reactivesputtering under the atmosphere of O2 and N2. Ni-Cr alloy was chosen as targetmaterial and copper sheets as substrate. Using SEM, Spectrophotometer and Talystepto analyze the relations between the selective characteristic and the structure, theformation and the thickness of the thin films. The aim is to obtain good solar selectivethin films with high absorptance and low emittance, which is applied to flat plate solarheat collectors.
关键词:
solar selective thin film
,
null
,
null
,
null
