D. N. He
,
X. F. Yin
,
H. Z. Thao
,
D. L*
,
X. Y. Ruan
,
J. L. Cheng and J. Y. Jiang 1) Shanghai Jiao Tong University
,
National Die & Mold CAD E. R. C
,
Shanghai 200030
,
China 2) Shanghai Vopkswagen Automotive Company Ltd.
,
Shanghai 201805
,
China Manuscript received
金属学报(英文版)
The deformation characteristic of bland in deep drawing is discussed. It is pointed out that the friction and lubrication conditions in for drawing are different from that in mechanical motion or machine work or other plastic process. The common test methods in laboratories are analyzed. It shows that though all those test methods can test the friction coefficient, the probe test method is most suitable for the research of friction and lubrication and the process in deep drawing, for this method is identical with the actual work condition either from the test principle or deformation status of the blank. Last the successful application in the deep drawing simulator newly developed the the probe method are intro- duced in detail.
关键词:
deep drawing
,
null
,
null
,
null
Micron
According to the HRTEM study, the UHP jadeite-quartzite mineral (Rutile, TiO2) in Anhui Province, Dabie Mountains, China, has ultrastructures such as <011> two-dimensional commensurable modulated structures or superstructures, {011} twin domain structures, dislocations and crystal deformations. The SAED patterns and HRTEM images indicate the existence of the deformations and stacking faults on the interface of {011} twin crystal of rutile and its two-dimensional commensurate modulated structures with repetition period 0.753 nm (3d(011)) has tetragonal symmetry, cell parameters a = 3a(0) = 1.377 nm (a(0) = 0.459 nm), c = c(0) = 0.3 nm. The modulated structures of rutile were probably caused by the isomorphic replacement of Ti4+ and position modulation or occupation modulation of oxygen atoms in different degree; the deformation structures reveal that during the process of crystallization and mineralization, this mineral may be affected by the geological environment (such as temperature, pressure and stress), metamorphism and deformation. (C) 2004 Elsevier Ltd. All rights reserved.
关键词:
ultrahigh-pressure metamorphic rocks;rutile;domain structure;TEM;Dabic Mountains;eclogites;anatase;tio2;tem
Z.L. Ding
,
Y.C. Fan
,
H.B. Qi
,
D.L. Ren
,
J.B. Guo and Z.Q. Jiang Shijiazhuang Railway Institute
,
Shijiazhuang 050043
,
China
金属学报(英文版)
The SiC_p/Al-alloy composite front broke rotors designed for SHANGHAI SANTANA cars were prepared by semi-solid stirring+liquid for ping process. The properties of the composite rotors were examined. The composite brake rotors were subjected to dynamometer tests on a SCHENCK broke testing system, referring to TLll0 standard of VOLKSWAGEN Company. The friction coefficient and thermal response during fade testing and the wear performance of the composite rotors were studied as the function of various parameters, such as braking pressures, initial speeds, initial temperatures, torque and decelerations, and compared with that of conventional cast iron rotors. The results showed that the properties of SiC_p,/Al-alloy composite rotors can achieve the requirements of commercial cast iron rotor.s. The results also suggested that the friction coefficients of composite rotors under different broking conditions are within the deviation band specified by the TLll0 standard, and the temperature rise of the composite rotors at the cud of each fade stop is lower than that of the cast iron rotors. The wear resistance of composite rotors was higher than that of cast iron rotors. The friction and wear mechanism are analyzed.
关键词:
SiC_p/Al-alloy composite
,
null
,
null
,
null
International Journal of Vehicle Design
Taking the forming processes of half-shaft bushing, wayshaft, and starter socket as examples and aiming at the typical problems in extrusion of automotive parts, some defects such as folding, underfilling, and cracking were numerically simulated and predicted in this paper with rigid-plastic FEM, rigid-viscoplastic FEM, and thermo-mechanically coupled methods by means of DEFORM3D. The distribution laws for the stress, strain, velocity, and temperature in the forming processes were analysed. The reasons for the defect generation were discussed, and some optimum measures for these processes were put forward. The results agree well with the experiments. Several proposals for prediction and simulation of extrusion defects of these automotive parts are put forward. It was instructional to apply FEM to the quality control of the extrusion.
关键词:
extrusion defect;numerical simulation;half-shaft bushing;wayshaft;starter socket;folding;underfilling;crack
SUN Wenqiang
,
CAI Jiuju
,
MAO Hujun
,
GUAN Duojiao
钢铁研究学报(英文版)
As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China′s iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.
关键词:
CO2 emissions
,
energy use
,
LMDI technique
,
steel production
,
energy consumption
XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaCHEN Renvi MEI Dongsheng Panzhihua Institute of Iron and Steel Research
,
Ministry of Metallurgical Industry
,
Panzhihua
,
China associate professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The determination of dffusible hydrogen in U71Mn heavy rail steel,and hydrogen diffusivity as well as the hydrogen distribution in the cross section of blooms with stack cooling were stu- died.The results showed that,most of the hydrogen in blooms of heavv rail steel is diffusible, the hydrogen diffusivity in U71Mn rail steel blooms at room temperature is(0.85—1.02)× 10~(-6)cm~2/s,after stack cooling,the hydrogen content in bloom will decrease greatly which is helpful to form the flake-free phenomenon in the heavy rail produced by Panzhihua Iron and Steel Company.
关键词:
rail steel
,
null
,
null
,
null
Intermetallics
Centrifugal casting has been used to cast TiAl car valves. The casting has been carried out in vacuum using induction melting furnace coupled to a CaO crucible, which offers a maximum superheat of approximately 180 degrees C and much improved filling over normal cold wall induction furnace. In this work, the effects of the casting conditions, including superheat, rotation speed at one mould temperature have been investigated in terms of the product integrity and porosity and the microstructure of the valves. The mechanical properties and oxygen contents of cast stems with various degrees of superheat have been measured at room temperature. The as-cast car valves and some HIPped car valves have been successfully engine-tested. The feasibility for mass production of TiAl car valves and realistic costing for producing car valves using centrifugal casting and CaO crucible are currently also being assessed. (c) 2004 Elsevier Ltd. All rights reserved.
关键词:
titanium aluminides;based on TiAl;mechanical properties at ambient;temperature;casting;microstructure;automotive uses;including engines;tensile properties;microstructure;alloy
