DU Hegui
,
ZOU Anhua
,
Northeast University of Technology
,
Shenyang
,
China Du Hegui
,
Professor
,
Department of Ferrous Metallurgy
,
Northeast University of Technology
,
Shenyang 110006
,
China
金属学报(英文版)
A study was carried out on the formation of Ti(C,N) during smelting vanadium-bearing titanomagnetite in blast furnace and the influence of MnO content on reduction of TiO_2 in the slag containing high titania. The reduction of TiO_2 is restricted by MnOpredominantly at the slag-metal interface and no more at the slag-coke one. The formation of Ti(C,N) is remarkably restricted by MnO in the slag when the MnO content is about 4% and the basicity from 0.6 to 1.2 in the slag. MnO may also retards the reduction of SiO_2 and accelerates the desulphidation under certain condition.
关键词:
blast furnace smelting
,
null
,
null
,
null
,
null
ZHANG Xiumu LI Yiyi Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
In situ observations of the nucleation and growth of ferrous martensites,including ε-, lenticular,butterfly,thin-plate and composite-plate ones at low temperature stage on optical or transmission electron microscope were carried out.The results confirmed the faulting model for the formation of ε-martensite proposed by Olso and Cohen.The grain boundaries and tri- ple points are the favourable nucleation sites for the thin plates,and their surface relief grown initially like a small needle.The lenticular martensite was observed as two stages of formation.According to the dislocation resolving reaction. (a/6)[111]_b→(a/3)[]_b+(a/2)[111]_b,the emission dislocation(=(a/2)[111]_b)acting as the dislocation source for the transition of lattice invariant shear from twinning to slip was proposed.
关键词:
martensite
,
null
,
null
,
null
,
null
LIU Chengjun
,
SHI Peiyang
,
ZHANG Dayong
,
JIANG Maofa
钢铁研究学报(英文版)
A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.
关键词:
glass ceramics;ferrous tailings;slag
Electrochimica Acta
To investigate the corrosion protection mechanism of polyaniline (PANI) films on ferrous metals, this work presents preparation method of a separate protonated PANI film electrode and results of its open-circuit potential (OCP) in 0.5 M NaClO4 and 0.5 M Na2SO4 solutions with different pH and the galvanic interaction between the PANI film electrode and ferrous metals. X-ray photoelectron spectroscopy (XPS) shows the lower pH corresponds to higher protonation level of H+ in the film, and a more positive OCP of PANI film. The PANI film accelerated the corrosion of 20A carbon steel slightly with a PANI to steel area ratio less than 25: 1, while the PANI films maintained passivity for a ratio above to 25:1 for the 20A steel. For the coupling of 2Cr13 stainless steel/PANI, an equal area PANI film could maintain 2Cr13 in a passive state. The results suggest that corrosion protection of 20A carbon steel and 2Cr13 stainless steel by PANI film in the acid solution is due to passivity protection. The excess oxidative charge stored in the PANI and the equilibrium activity of protonated PANI with the acid environment provide a persistent driving force for carbon steel and 2Cr13 stainless steel passivity. (C) 2004 Elsevier Ltd. All rights reserved.
关键词:
protonated polyaniline;ferrous metals;open-circuit potential;galvanic;coupling;passivity;corrosion protection;mild-steel;coatings;behavior
LIU Chunpeng XU Yousheng HUA Yixin Kunming Institute of Technology
,
Kunming
,
650093
,
China.
材料科学技术（英文）
In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of common useful minerals have been individually irradiated by a 500 W,2450 MHz microwave source in an enclosed quartz crucible to ascertain their heating temperature in a definite time.In addition,the reduction and cbloridization tests were also carried out on the titanomagnetite concentrate and pentlandite with microwave heating,respectively. These experiments indicate potential applications of util- izing microwave energy in extractive metallurgy.
关键词:
microwave radiation
,
null
,
null
,
null
HU Chang-qing
,
HAN Tao
,
ZHANG Yu-zhu
,
ZHANG Zhi-xia
钢铁研究学报(英文版)
For the recycling of ferrous sludge from steel industry, the carbonation pellet process should be considered as a “green” process, since no impurities are added as well as CO2 can be sequestrated and consumed. Through the thermodynamic calculation, the carbonation reaction can occur spontaneously and is an exothermic reaction. Based on the kinetic analysis through unreacted core model, the interfacial chemical reaction was the rate controlling step in the initial fast stage of carbonation, and the CO2 diffusion through the CaCO3 product layer was the rate controlling step in the following extremely slow stage. For the carbonation bonded mechanism, the pellet strength was gained by the formation and growing of CaCO3 product layer. Since the interfacial chemical reaction was the critical stage of the entire carbonation process, the emphasizes should be focused on the improvement of sorbent activity and the optimization of process parameters, such as pore structure, pore surface area, and total pressure, CO2 partial pressure, reaction temperature, etc to accelerate the reaction rate and to improve the quality of carbonation pellets.
关键词:
CO2 sequestration
,
ferrous sludge
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carbonation pellet
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thermodynamics
,
kinetics
,
unreacted core model
Journal De Physique Iv
Transformation plasticity deformation mechanisms are reviewed in the case of ferrous alloys. From experimental data, microstructural observations and numerical simulations the contributions of the different mechanisms are discussed and a schematic diagram of these evolution is proposed depending on the applied stresses and the test condition.
关键词:
plasticity;steels;model
Materials and Corrosion-Werkstoffe Und Korrosion
In order to investigate the galvanic anodic protection (GAP) of ferrous metals (such as 410, 304 and 316 stainless steels) in acid solutions by doped polyaniline (PANi), separate doped PANi powder-pressed electrodes with different surface areas (the area ratio of the PANi electrode to stainless steel is between 1:1 and 1:2) have been prepared. These were coupled with ferrous metal in the following solutions: 5 M sulphuric acid, 5 M phosphoric acid and industrial phosphoric acid (containing 5 M phosphoric acid and 0.05% chloride ion) to construct a galvanic cell, in which PANi is cathode while ferrous metal is anode. The results indicate that a PANi electrode with sufficient area can provide corrosion protection to stainless steel in these acidic solutions. A pilot scale coupling experiment was carried out. The results indicate that PANi is a promising material as an electrode for the anodic protection of ferrous metals in acidic solutions in industrial situations.
关键词:
conducting polymer-coatings;corrosion protection;stainless-steel;spectroscopy;passivation;performance;mechanism;behavior;primers;films
