钢铁钒钛

Study on Reduction Kinetics of Vanadium in CaO-SiO₂-Al₂O₃-MgO-V₂O₅ Slag System

Yang Yong, Song Bo, Jiang Junpu, Cai Kaike, Yang Subo, Wen Yongcai

2005, 26(4): 1-6.

Abstract(16) PDF(1)

Abstract:
Under the laboratorial conditions, using CaO-SiO₂-Al₂O₃-MgO-V₂O₅ slag as the base slag system, kinetic study on the reaction of reducing V₂O₅ by carbon saturated molten iron was carried on.The influence of the factors, such as time, temperature, slag basicity, slag compositions, initial V₂O₅ concentration, etc., to the rate and reduction degree of the reaction was investigated.The experimental results show that V₂O₅ content in the slag decreases gradually with the time extending, meanwhile the content of V in molten iron increases gradually.The conditions of high temperature, proper slag basicity, high weight ratio between liquid iron and slag and high initial V₂O₅ content can make the reducing reaction fast and obtain high reduction degree.

Research on Properties of Coke in BF with High Ti Type Vanadic Titanomagnetite

Jiang Sheng

2005, 26(4): 7-11.

Abstract(19) PDF(1)

Abstract:
A series of study was took out with charging coke and tuyere coke,such as thermal effect active,coal solution loss,mineral(TiO₂,Alkali metal) and slag-iron attack,so the solution loss of coke in BF with high Ti type vanadic titanomagnetite was understood.The results show that the CRI increases and the thermal stength of coke decreases with the alkali load of burden rising.The starting reaction temperature average of coke is 862℃ and the violent reaction temperature average is 1 266℃ in BF with smelting vanadic titanomagnetite.The gasificating reaction of the coke is the main solution loss reaction,and the TiO₂ in slag-iron protects the coke against solution loss.

Investigation on Anti-seismic Properties of HRB400 Reinforced Steel Bar

Liao Hongjun, Sheng Guangmin, Gong Shihong, Jiang Bin

2005, 26(4): 12-16.

Abstract(25) PDF(1)

Abstract:
The anti-seismic properties,i.e.the coordination of strength and ductility,sensibility of strain aging,brittleness at low temperature and weldability were systematically investigated for 20MnSiV HRB400 reinforced steel bar with the diameter of 20 mm.Test results showed the DBTT of strain aged steel bars rose,and the anti-seismic properties of the steel bars at low temperature were poor.The C_eq value of the steel bar was slightly high,as a result the weldability should be advaced.The results of microstructure observation showed that the content of micro-alloying elements should be adjusted in order to enhance anti-seismic properties of steel bar.

Study on Antibacterial property and Degradation Formaldehyde of Interior Latex Coating Modified by Nano-TiO₂

Wu Jianchun

2005, 26(4): 17-21.

Abstract(25) PDF(1)

Abstract:
After analyzed the photocatalytic theory of nano-TiO₂ and the antibacterial theory of Ag⁺ and Ce⁴⁺, interior latex coatings were modified by anatase nano-TiO₂ loading Ag⁺ and Ce⁴⁺ to prepare environmental protection coatings with air cleaning and antibbacterial ability.The qualitative antibacterial annulus, quantitative antibacterial rate and degradation formaldehyde of modified interior latex coating were tested.The results show that the interior latex coatings modified by anatase nano-TiO₂ loading Ag⁺ and Ce⁴⁺ have good inhibiting bacterium and degrading formaldehyde ability.The antibacterial rate exceeded 99% after 24 h and over 75% formaldehyde was degraded after 8 h irradiation with 40 W daylight lamp.

Catalytic Performance of TiO₂ Nano-particles Supported Pd Catalyst

Xia Xianbo, Huang Weigang, Shen Xiaoxiao, Tu Mingjing

2005, 26(4): 22-25.

Abstract(29) PDF(1)

Abstract:
TiO₂ nano-particles supported Pd catalyst was prepared by impregnation method.The effect of rare earth element La and space velocity on the catalytic performance was investigated by using selective hydrogenation of acetylene to prepare ethylene as reaction model.The catalytic performance of RiO₂ nano-particles supported Pd catalyst and Pd-La/SiO₂ catalyst using nanometer SiO₂ as carrier was compared.The experimental results show that Pd/TiO₂ catalyst has excellent catalytic activity and performance stability.The La promoter remarkably improves the selectivity of ethylene,and the increasing of ethylene selectivity reaches 40%.The optimal space velocity is 18 000 h^-1.The ethylene selectivity on the Pd-La/TiO₂ catalyst is higher than that on the Pd-La/SiO₂ catalyst.

Research Advance of Nanometer TiO₂ Photocatalysis

Zhang Wenbin, Zhou Yan

2005, 26(4): 26-33.

Abstract(20) PDF(1)

Abstract:
Based on the analyzing for crystal structure of nanometer titanium dioxide,the photocatalysis principle,preparing technique,modification and analysis methods of nano-TiO₂ were discussed.The difference of rutile type TiO₂ and anatase type TiO₂ in photocatalysis ability were presented.It was clarified that anatase type TiO₂ nano-crystal had better photocatalysis ability than rutile type TiO₂ since having more mass transfer interspace.Improvement of photocatalysis performance should be actualizde in terms of reducing the electric field tie of O to Ti.The newly research results of photocatalysis technique in different application field were introduced.

Study on Roll of in-situ Synthesized Particulates Reinforced Ferrous Matrix Composites

Fu Hanguang, Li Mingwei, Zhang Yi

2005, 26(4): 34-38.

Abstract(24) PDF(1)

Abstract:
The usual alloy cast iron roll has low hardness and poor abrasion resistance,but the hard alloy roll with good abrasion resistance has high production cost and large brittleness,so an in-situ synthesized particulate reinforced ferrous matrix composites roll having high abrasion resistance was developed by means of centrifugal casting technique.The main problems for producing ferrous matrix composites roll,such as segregation and crackle,were solved.Its hardness is 66~68HRC and the hardness balance on the roll surface is smaller than 2HRC,its impact toughness is over 18 J/cm².Used in the pre-presision rolling machine group of high speed wire rod mill,the developed roll has 8~10 times longer service life than that of alloy cast iron roll,nears hard alloy roll.

Study on Static Recrystallization of Ti-IF Steels in Multi-pass Ferrite Deformation

Xu Guang, Xu Chushao, Zhao Jiarong, Liu Xianjun, Xiong Junwei

2005, 26(4): 39-42.

Abstract(14) PDF(1)

Abstract:
The experiments of multi-pass ferrite hot deformation of Ti-IF steels were carried out with hot simulator.The static recrystallization fractions for test steels were determined by back-extrapolation method.The dynamic models of static recrystallization for Ti-IF steels in multi-pass ferrite deformation were deduced on the basis of experiments.The test results show that the predicted values of static recrystallization dynamic models for Ti-IF steel confirm with the test values.

Numerical Simulation of Steel Flow Characteristics in Tundish with Argon Bottom Blowing

Zhang Meijie, Wang Houzhi, Huang Ao, Gu Huazhi, Liu Dingqun

2005, 26(4): 43-46,64.

Abstract(21) PDF(1)

Abstract:
According to the structure and the tundish operating parameters of a production plant,the flow charecteristics of steel in the tundish with turbulence inhibitor and gas curtain technique was researched by numerical simulation method.Eulerian-multiphase model and porous media model were applied in the research.The effect of gas curtain position and gas flow rate on the flow characteristics of steel in the tundish was investigated.The results indicate that the position of gas blowing and gas flow rate has remarkable effect on the steel fluid flow and RTD curve.It is disadvantageous to the steel fluid flow if the position of gas blowing is near the inlet or outlet.There is an optimum range for the gas flow rate,too large is liable induce slag rolling but too small is disadvantage to forming gas curtain.When the distance of gas blowing position from the inlet is 1 200~2 000 mm meanwhtile the gas flow rate is 0.90 m³/h,the residence time of fluid in tundish will be effectively prolonged and the dead zone volume will be decreased,and so accelerate the removal of inclusions.

Finite-element Simulation & Analysis in Steel Tube Tiny-tension Reducing Process

Lü Lihua, Ma Jinjiang, Yuan Quan, Lin Jun, Liu Weiguang, Zhang Yongwei

2005, 26(4): 47-51.

Abstract(22) PDF(2)

Abstract:
The deforming situation of seamless steel tube in the tension reducing process was simulated by means of a large-scale and common finite-element analysis software ANSYS/LS-DYNA,this simulation could present the deforming situation objectively.The simulated distribution of the stress and the strain could well explain the phenomenon of unequal wall thickness in the tension reducing process.The simulation process for deforming is almost the same as the practical once.This research conclusing could be used for analyzing,establishing and optimizing the technological system in the steel tube reducing process.

Sinulation Study on Spout Characteristics in Bottom Blowing Slag Ladle

Wang Mingyu, Zhang Li, Zhang Linnan, Sui Zhitong, Tu Ganfeng

2005, 26(4): 52-54,64.

Abstract(19) PDF(1)

Abstract:
Based on the technology of selective precipitation,titanium bearing molten slag in ladle is supposed to be oxidized by air for achieving selective enrichment of titanium component.The height and width of spouts surface have great effect on the design of slag ladle free space.In the present study,a water model of slag ladle was used with a photographic technique to determine the effect of viscosity and bottom stirring gas flow rate on surface spout characteristics of the solution.As the result,the spout shapes were found to be Gaussian.The spout heights increased with the gas flow rate increasing,while there was not obvious effect of the viscosity on it.The spout widths increased with the increasing of gas flow rate and viscosity,but were affected mainly by flow rate.Based on the experimental results and analysis,empirical equations were developed for the height and width.

Fracture Analysis of Diffusion-bonded Joint Between Titanium Alloy and Stainless Steel

Qin Bin, Sheng Guangmin, Huang Jiawei, Zhou Bo, Qiu Shaoyu, Li Cong

2005, 26(4): 55-59.

Abstract(33) PDF(1)

Abstract:
After phase transformation diffusion bonding of TA17/0Cr18Ni9Ti, the fractures in the bonded joint were observed.The microstructure and fracture mechanism of the joint were investigated.There formed β-Ti, FeTi, Fe₂Ti and σ phase around the bonding interface since the interdiffusion of Ti, Fe and Cr atoms.Tensile fracture occurred in FeTi and β-Ti under the tensile load because of the flaws and residual stress.The joint was sensitive to flaws, and the joint strength could be greatly reduced since the presence of chamfer, scratch or pores.

Three Top Products in Titanium Metallurgy Industry

Deng Guozhu

2005, 26(4): 60-64.

Abstract(21) PDF(1)

Abstract:
The development outline for three top products in the titanium metallurgy industry,sponge titanium,ferrotitanium with high titanium and nanometer titanium dioxide,was introduced.Three points of view on developing these products are presented.①The market of metal titanium is not stable,enlargement of sponge titanium production should be conducted step by step.②The direct reduction method of titanium ore may be a reasonable process for production of ferrotitanium with high titanium.③The gas phase reaction method for producing nanometer titanium dioxide may be an effective process to realize its large scale production.

Wang Yuansun

2005, 26(4): 65-66.

Abstract(21) PDF(1)

Abstract:

2005 Vol. 26, No. 4