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
XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaCHEN Renyi MEI Dongsheng Panzhihua Institute of Iron and Steel Research
,
Panzhihua
,
China associate professor.Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
At panzhihua Iron and Steel Company,hydrogen content in molten heavy rail steel is rather low during smelting in the oxygen top-blown converter,and sloightly increases in tapping and pouring.Average H content varies from 2.0(dry season)to 2.4 ppm(rainy season)at smelt- ing end;2.8 ppm in ladle;and 2.1 ppm(dry season)to 2.3 ppm(rainy season)in mould, which is on a level with RH vacuum circle.The low hydrogen content in molten steel,which is due to both the very dry climate in Panzhiihua region and the LD smelting process,is the main reason why there is little flake in the heavy rail produced by Panzhihua Iron and Steel Com- pany.
关键词:
smelting
,
null
,
null
,
null
,
null
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
American Mineralogist
A natural high-pressure phase of titanium oxide with alpha-PbO2-structure has been found in omphacite from coesite-bearing eclogite at Shima in the Dabie Mountains, China. High-resolution transmission electron microscope observations have revealed an orthorhombic lattice, corresponding to alpha-PbO2-type TiO2, with cell parameters a = 0.461 nm, b = 0.540 nm, c = 0.497 nm and space group Pbcn. It occurs as nanometer-thick (< 2 nm) lamellae between multiple twinned rutile crystals, providing additional evidence of very high-pressure, metamorphism at 7 GPa, 900 degrees C. This implies subduction of continental material to a depth of more than 200 kilometers. alpha-PbO-type TiO2 could be an extremely useful index mineral for ultrahigh-pressure.
关键词:
high-pressure phase;ries crater;rutile;polymorph;titanium
Corrosion Science
Most of the former studies on cavitation erosion (CE) in corrosive media were carried out in NaCl solutions. In contrast, the effects of SO(4)(2-) and HCO(3)(-) ions, which are dominant anions in most rivers of China, on cavitation erosion have not been investigated systematically. In this paper, the cavitation erosion behaviour of 20SiMn low alloy steel in Na(2)SO(4) and NaHCO(3) solutions was investigated by using a magnetostrictive-induced CE facility. The micrographs of damaged surfaces were observed by scanning electron microscope (SEM). It was found that the CE rate of 20SiMn low alloy steel in 0.003% Na(2)SO(4) solution was higher than that in 0.003% NaCl solution, but in 0.03%, 0.3%, and 3% solutions their CE rate was almost the same. The CE rate of 20SiMn low alloy steel in 0.0033% NaHCO(3) solutions was higher than that in the equivalent 0.003-3% Na(2)SO(4) and 0.003-3% NaCl solutions, which may be related to stress corrosion cracking or corrosion fatigue mechanism in NaHCO(3) solutions. The role of corrosion was analyzed by using polarization curves, electrochemical impedance spectroscopy (EIS), linear polarization resistance and the corrosion potential with or without cavitation. Independent of the test media, cavitation shifted the corrosion potential in the positive direction and strongly enhanced the cathodic current density in the polarization curves. In the interaction of cavitation erosion and corrosion, the corrosion-induced erosion component was predominant. Cavitation also greatly reduced the magnitude of impedance though the initial impedance under cavitation conditions in 3% NaHCO(3) solution was almost one order larger than that in 3% Na(2)SO(4) solution. (c) 2005 Elsevier Ltd. All rights reserved.
关键词:
cavitation erosion;20SiMn low alloy steel;corrosion;microstructure;electrochemical tests;SO(4)(2-) ion;HCO(3)(-) ion;synergistic effects;stress-corrosion cracking;duplex stainless-steel;bicarbonate;solutions;chloride;iron;mechanism
