钢铁钒钛

RESEARCH ON CONTROLLED COOLING OF H-BEAM

FENG Jian-hui, ZHANG Hui-yi, QIAN Yi-feng, XU Guang-yuan

2003, 24(3): 1-5.

Abstract(59) PDF(1)

Abstract:
An experimental device of H-beam controlled cooling was designed and installed, in order to eliminate or reduce the defects of H-beam, such as the inadequate of wing strength and the uneven-distributed of survival stress in the process of rear cooling after rolling. The research trials on controlled cooling of H-beam were carried out. During the controlled cooling process of heavy section H-beam, the cooling rate at wing surface exceeds 20℃/s, the cooling rate at interface of wing and web plate surpasses 30℃/s.The research results are the foundation of installing online controlled cooling equipment.

DEVELOPMENT OF JT245 CORROSION-RESISTANT TOWER STRUCTURAL STEEL

XIA Mao-sen, CAI Zhang-ping, JIANG Shan-yu, GU Bao-shan

2003, 24(3): 6-10.

Abstract(56) PDF(1)

Abstract:
The tower structural steel JT245 produced in Jinan Iron and Steel Ltd.Co.was developed by alloying addition Cu、P、Nb etc.Because of the alloying element, tight and continuous amorphous layer was formed on steel plate.As a result,the steel plate is of good corrosion-resisting atmosphere properties.The JT245 steel plate also has good mechanical property and weldability.The steel plate could meet the need of tower structure very well.

STUDY OF CARBONIZATION AND DESULFURIZATION FOR SEMI-STEEL PRODUCED IN SMELTING OF TITANIUM SLAG

LIAO Rong-hua

2003, 24(3): 11-16.

Abstract(67) PDF(2)

Abstract:
As a byproduct produced in smelting of titanium slag,semi-steel could be the raw of cooling agent used in extraction of vanadium,spheroidal graphite cast iron,casting pig and low-carbon pig iron.According to the quality of semi-steel and the market demand for iron-raw,the technologies for carbonizing,desulfurizing and alloying of semi-steel were studied.The above-mentioned products maded from semi-steel are of good economical benefits.

BEHAVIOR OF UNBURNED PARTICLE IN BLAST FURNACE PULVERIZED COAL INJECTION

DIAO Ri-sheng, HU Bin-sheng

2003, 24(3): 17-21.

Abstract(47) PDF(1)

Abstract:
The behaviors of unburned particle of PCI in blast furnace were studied on the simulation conditions of BF at PZH Steel. The unburned particle of PCI shows better reactivity than the coke in a series of test,such as the direct reduction of iron ore,carburizing of pig iron,reduction of silica and titanum oxide,sedimentation in slag, reaction with CO₂. The results are due to the larger specific surface of unburned particle of PCI than that of coke.

IN SITU SYNTHESIS OF Fe-TiC COMOPOSITES UNDER GREAT THERMAL FLUX

FENG Ke-qin, YANG Yi, SHEN Bao-luo, DONG Ling-yan, GUO Lu-bao

2003, 24(3): 22-25.

Abstract(54) PDF(1)

Abstract:
In situ synthesis of Fe-TiC composites was investigated firstly using Gleeble thermal simulation apparatus under the great thermal flux in the Fe-Ti-C system. A series of studying was taken,such as the temperature feature of compact in the process of heating, the thermodynamic calculation,the analysis of the final product by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersion spectrometry (EDS). The results show that the starting temperature of synthesis reaction can be decreased greatly. In this study, the synthesis react can take place at a temperature as low as 394℃ in Fe-Ti-C system Besides the litter Particles TiC in Fe-binder phase, there is a little Fe₂Ti in the final products. The study provides a new route for producing Fe-TiC composites at low temperature.

OPTIMIZATION OF SECONDARY COOLING SCHEME FOR SLAB CONTINUOUS CASTING

CHEN Yong

2003, 24(3): 26-31.

Abstract(50) PDF(1)

Abstract:
Effects of the existing secondary cooling scheme on slab internal quality were evaluated based on strand temperature measurement at secondary cooling zones and macrostructure examination.Then,the secondary cooling scheme was optimized.The modified operation shows that the slab internal quality,particularly central segregation and equiaxed crystal ratio,is markedly improved by increasing the intensity of secondary cooling,particularly the secondary spray water in the lower part of the secondary cooling zones.The results have laid a foundation for further optimization of the secondary cooling scheme.

MICROSTRUCTURE OF ULTRA-FINE GRAIN STEEL

SONG Li-qiu, HOU Huo-ran, ZUO Jun, WANG Yi-cheng, LIU Qing-you, ZHANG Kai-jian, DONG Han

2003, 24(3): 32-36.

Abstract(50) PDF(1)

Abstract:
The microstructure of commercial ultra-fine grain steel with plain carbon composition was analyzed. The results show that the microstructure of ultra-fine grain steel is composed of ferrite and pearlite. The ferrite grain size is about 4~5 μm. The volume fraction of pearlite in the microstructure is relatively low. The cementite appears as small sticks and pellets in pearlite. Fine ferrite makes the dislocation density decrease in grain, and is beneficial to increase the strength and toughness of steel.

CHARACTERISTICS ANALYSIS OF FURNACE HEARTH SEDIMENT IN No.1 BLAST FURNACE AT PZH STEEL

FU Wei-guo, DIAO Ri-sheng, LI Jian-ming, SONG Guo-cai, LI Jing-ming

2003, 24(3): 37-41.

Abstract(39) PDF(1)

Abstract:
The changing characteristics and metallurgical property of furnace hearth sediment in No.1 blast furnace with 3^rd campaign life at PZH Steel were discussed.The forming mechanism of furnace hearth sediment and the corrosion mechanism of firebrick were researched with intensification of smelting process in blast furnace.The results are helpful to understand the hearth sediment in blast furnace smelting with V-Ti-bearing magnetite.

EFFECT OF BOF LINING EXPANSION JOINT ON CONTACT PRESSURE BETWEEN LINING AND SHELL

GUO Zhi-qiang, REN Xue-ping

2003, 24(3): 42-45.

Abstract(54) PDF(1)

Abstract:
The different expansion joint set in lining-up BOF will lead the different of contact pressure between lining and shell,and further produce different thermal-stress.Thanks to structural cause,measuring the contact pressure of lining and shell is relatively difficulty.with the help of FEM(finite element method),working process of BOF can be simulated and the contact pressure of lining and shell can be obtained through numerical simulation.The result is a necessary preparation for further analysis the reasonableness of lining masonry and the thermal-stress of lining.

COMMERCIAL TRIAL-PRODUCTION OF HRB400 REINFORCED BAR WITH V-N MICROALLOYING

SU Shi-huai, WAN Wei-guo, ZHANG Ruo-qiang, ZHAO Ming-qi, WANG Ying

2003, 24(3): 46-51.

Abstract(55) PDF(1)

Abstract:
The commercial trial-production of V-N microalloyed HRB400 reinforced bar in Magang is Presented.The influence of V-N microalloying on the property of reinforced bar are studied.The relations among microalloying process and microstructure of reinforced bar,nitrogen-enhancing,Strengthenlng are analyzed.The result shows that the process technique used by Magang to produce the microalloyed HRB400 reinforced bar is stable and reliable.The property of trial-produced HRB400 reinforced bar not only can meet the quality requirements,but also has stability and high ratio of tensile to YS.

STUDY OF SCALE REMOVAL TECHNIQUE FOR HOT STRIP STEEL

XUE Nian-fu, LI Li, CHEN Ji-lin, PEI You-cai, SHE Guang-fu, JIAO Jing-min

2003, 24(3): 52-59.

Abstract(60) PDF(1)

Abstract:
The descaling process technique was dereloped and optimized based on the investigating of technological parameter influence on descaling result, such as slab reheating process,structure characteristics, of furnace scale, scale removal times, rolling temperature variation and so on.The practical operation shiows the descaling efficiency of furnace scale is 100%, and the total descaling efficiency of hot strip steel is 99.78%.

PRODUCING NON-QUENCHED AND TEMPERED N80 CLASS OIL PIPE STEEL BY V-N MICROALLOYING

YAN Ling, WANG Zhang-shun, DONG En-long, XU Yong-mei

2003, 24(3): 60-63.

Abstract(38) PDF(1)

Abstract:
The N80 class oil pipe was produced by V-N microalloying and controlled temperature rolling instead of quenching-tempering.The N80 class oil pipe steel has good performance and satisfies the request of API Spec 5CT.The practical production indicated the new process,V-N microalloying and controlled temperature rolling,is practicable.It not only simplifies the production process,but also reduces the production cost.

RESEARCH ON STRUCTURE AND PROPERTIES OF LOCAL DIRECTIONAL SOLIDIFICATION FOR BLADE OF HIGH CHROMIUM CAST IRON

WU Guang-bo, HE Tong-zheng

2003, 24(3): 64-69.

Abstract(46) PDF(1)

Abstract:
The relationship between local directional solidification structure and property for high chromium cast iron blade was studied in laboratory.The blade was tested on commercial plant.The influence of local directional solidification on microstructure, hardness, density and wear resistance were determined.The proper directional solidification process was proposed.The service life of high chromium cast iron blade is significantly prolonged.

2003 Vol. 24, No. 3