钢铁
Home
|
About Journal
|
Editorial Board
|
Instruction for Authors
|
Subscriptions
|
Advertisement
|
Contacts Us
|
Chinese
Office Online
Author Center
Peer Review
Editor Work
Office Work
Editor-in-chief
Journal Online
Forthcoming Articles
Current Issue
Archive
Read Articles
Download Articles
Email Alert
Quick Search
Advanced Search
2020 Vol. 55 No. 4
Published: 2020-04-15
Technical Reviews
Raw Material and Ironmaking
Steelmaking
Metal Forming
Materials
Environmental Protection and Energy
Equipment Technology
Technical Reviews
1
ZHANG Jian-liang, SUN Min-min, LI Ke-jiang, LI Hong-tao
Present situation and prospect of dissolution behavior of metallurgical coke in blast furnace hot metal
Under the condition of high melting intensity of current and future blast furnace, enhancing the coke dissolution rate and improving the carbon saturation in hot metal are critical to weaken the attack of unsaturated melt at the lining and ensure the smooth operation of hearth of blast furnace, which can also provide some of the heat source for the downstream steelmaking process. The experimental and simulation methods of coke dissolution into molten iron were summarized, and influencing factors of the coke dissolution rate, such as coke structure and properties, minerals in coke and physical properties of molten iron, were analyzed in detail. The results show that the increase of carbon crystallinity and hot metal temperature are beneficial to the dissolution of coke, while the presence of minerals in coke and impurity elements S and P in molten iron inhibit the further carburization. The research results can provide a reference for the production operation of carburization in BF and the energy-saving and emission reduction in the iron and steel industry.
2020 Vol. 55 (4): 1-11 [
Abstract
] (
672
) [
HTML
1KB] [
PDF
5091KB] (
769
)
Raw Material and Ironmaking
12
WU Hao, ZOU Chong, HE Jiang-yong, WANG Wei-an, LIU Zhan-wei, SHI Shuai
Difference of combustion performance between different pyrolytic char and pulverized coal injection in blast furnace
Studying the combustion performance of different char and pulverized coal injection is conducive to char injection in the blast furnace and reducing the cost of ironmaking. Different char samples were prepared in a tube furnace by changing the pyrolysis temperature, pyrolysis rate, pyrolysis holding time and pyrolysis atmosphere, and the changes in specific surface area, calorific value and activation energy were measured by proximate analysis and thermogravimetric experiments. The differences in combustion performance between different pyrolysis chars and two kinds of injected pulverized coals were studied. The results show that the combustion performances of chars prepared under different pyrolysis conditions are mostly between two kinds of injected coals, and the pyrolysis temperature is the most important factor affecting the char reaction performance. With the temperature increasing, the activation energy of char during combustion first decreases and then increases. The char pore structures prepared by different pyrolysis temperatures are more developed than the injected coal, and the cumulative pore volume and specific surface area both increase first and then decrease, which is basic correspond to the combustion performance. The temperature of 550 ℃ is a suitable pyrolysis temperature for the preparation of highly reactive char, which is a benefit to control the pyrolysis conditions to prepare high reactivity char, and it is also conducive to the application of char in the blast furnace injection.
2020 Vol. 55 (4): 12-19 [
Abstract
] (
457
) [
HTML
1KB] [
PDF
910KB] (
562
)
20
GUO De-ying, LI Dong-tao, ZHANG Xiao-ming, MA Chao, DAI Xin, LIU Yang
Optical structure and thermal and cold properties of different rank coal coke
In order to study the influence of coal metamorphism on coke optical structure and the relationship between coke optical structure and cold-hot properties, the maximum reflectance of vitrinite of more than 30 coking coals and the optical structure and cold and hot properties of coke after coking were tested.The results demonstrated that coke optical textures displayed regular changes with the degrees of coal metamorphism. The results show that the optical structure of coke changes regularly with the degree of metamorphism of coking coal, and the volume percent of mosaic structure can be divided into three stages: rapid increase, steady and slow decrease with the maximum reflectance of vitrinite; the change trend of ∑ISO volume percent with the maximum reflectance of vitrinite is opposite. A regression equation can be established between the thermal and cold properties of coke and the volume percent of optical structure. The reactivity of coke increases with the increase of ∑ISO volume percent, while the strength after reaction increases with the increase of the volume percent of mosaic structure. After the regression equation is used to guide coking production, the economic benefit is remarkable.
2020 Vol. 55 (4): 20-26 [
Abstract
] (
471
) [
HTML
1KB] [
PDF
947KB] (
808
)
27
HU Chang-qing, WANG Xiao-lei, SHI Xue-feng, WANG Zhi-xing, HAN Wei-gang
Effect of MgO and basicity on liquid phase formation of FeO
x
-SiO
2
-CaO-MgO-Al
2
O
3
system
In order to study the effects of MgO content and alkalinity on the liquid phase formation characteristics of pellets and sinters. The five-element system of FeO
x
-SiO
2
-CaO-MgO-Al
2
O
3
is used as a research basis. By fixing the content of SiO
2
and Al
2
O
3
, and using the basicity and MgO content as variables, the method of FactSage simulation and melting point melting rate experimental data is used to analyze the influence of changes in MgO content and alkalinity on the liquid-phase formation characteristics of FeO
x
-SiO
2
-CaO-MgO-Al
2
O
3
system. Based on this, determine the optimal MgO content and alkalinity range of this five-element system is determined, and theoretical support for enterprise production practice is provided. The results show that when the MgO content of the system ranges from 1.5% to 3.0 %, the amount of high-melting-point compounds in the system increases with the increase of the content of MgO, which suppresses the generation of the liquid phase. It gradually shrinks, when the alkalinity is 2.0 and 1.8, the melting rate of the system is relatively stable and easy to control.
2020 Vol. 55 (4): 27-33 [
Abstract
] (
484
) [
HTML
1KB] [
PDF
2506KB] (
747
)
Steelmaking
34
ZHAO Zhong-yu, ZHAO Jun-xue, TAN Ze-xin, LU Liang, CUI Ya-ru, LI Xiao-ming
Determination and analysis of CaF
2
-Al
2
O
3
binary phase diagram based on volatilization effect
In order to effectively measure and evaluate the binary phase diagram of CaF
2
-Al
2
O
3
,the binary phase diagram of CaF
2
-Al
2
O
3
was drawn by FactSage software calculation and melting point tests. The eutectic point composition was 10% Al
2
O
3
-90% CaF
2
, and the eutectic temperature was 1 340 ℃. TG-DSC tests showed that the binary system had an obvious weight loss and endotherm during the heating process. The weight loss rate of 90% CaF
2
-10% Al
2
O
3
can reach 27% at 1 500 ℃ and the main volatile was CaF
2
. A new phase diagram of CaF
2
-Al
2
O
3
was obtained based on the weightlessness and volatilization reaction. The composition of the eutectic point was 12% Al
2
O
3
-88% CaF
2
, and the eutectic temperature was 1 340 ℃. Finally, the XRF detection results of the slag after melting are basically consistent with the new phase diagram. The results are of reference value to the determination of the melting point of slag containing volatile components and the drawing and analysis of phase diagram.
2020 Vol. 55 (4): 34-39 [
Abstract
] (
510
) [
HTML
1KB] [
PDF
1214KB] (
792
)
40
YANG Guang-wei, CHEN Zhao-ping, LIU Xiang-chun
Effect of non-calcium treatment on inclusions in high grade case hardening steel
Inclusions in tundish with and without calcium treatment are studied by thermodynamic calculations and industrial trials for SCr420H gear steel. It is found that the inclusion amount without calcium treatment is lower than that with calcium treatment. Inclusions without calcium treatment are mainly angular magnesia-alumina spinel, while those with calcium treatment are mainly spherical Al
2
O
3
-CaO-MgO and CaS composites. After optimizing the process, the number of spinel inclusions in tundish without calcium treatment was greatly reduced, and the problems of nozzle blockage and B-type inclusions were solved. The results of inclusion rating for round steel without calcium treatment are as follows: Type A ≤ 0.5, Type B≤ 0.5, Type C=0, Type D (thin)≤ 1.0, Type D (heavy)≤ 0.5, and Type Ds ≤ 1.0.
2020 Vol. 55 (4): 40-44 [
Abstract
] (
507
) [
HTML
1KB] [
PDF
1470KB] (
629
)
45
YANG Li-bin, ZENG Jia-qing, DENG Yong, XU Xiao-wei, WU Li-ping
Highly efficiency and long-life combined blowing technology of big converter
Through summarizing and the analysis of characteristics of the steelmaking process,the reasonable high efficiency and long-life combined blowing mechanism and choice were proposed. Laboratory experiments and research of slagging and element oxidation mechanisms were carried out to adapt the high efficiency refining control technique,in which the slagging characteristics and elements selective oxidation during blowing were estimated. The result showed that when the oxygen blowing intensity increased from 3.50 to 3.72 m
3
/(t·min),the refining dynamics demand of all periods can be satisfied eventually. When the bottom blowing intensity increased to 0.2 m
3
/(t·min).To assure combined blowing metallurgical results,the bottom blowing intensity and the flow pattern were vital,in which bottom blowing intensity,bottom tuyere type,bottom tuyere number,bottom blowing pattern and maintenance technique were the key influencing factors. Finally,a high efficiency and long-life combined blowing technology was constructed by combining the refining mechanism,dynamics requirement,and oxidizability control. After 10 years of practice, the effect was confirmed with a commercial 300 t converter. The reasonable results showed that the final w([C])·w([O]) product reduced to less than 0.001 5,the campaign with good result increased to 7 333,and the efficiency has been increased obviously.
2020 Vol. 55 (4): 45-52 [
Abstract
] (
542
) [
HTML
1KB] [
PDF
5020KB] (
775
)
Metal Forming
53
ZHENG Zhong, WANG Yong-zhou, LU Yi, GAO Xiao-qiang
Intelligent optimization model and system of plate and slab design of medium steel plate
The production orders of medium steel plate always come in small batches of various types and specifications,leading to difficulties for steel plants in combining the order plates into the mother plate and designing the slab. By making full use of the non-fixed length production orders and the uncertainty of slab specifications,an adaptive combination-optimization model is established to realize the integrated optimization design of mother plate and slab for orders of both one-dimensional and two-dimensional,and of both fixed length orders and non-fixed length. A corresponding software system is developed and tested against the production order data from a steel plant. The results show that the design generated by this model features has higher product yield and lower surplus material rate than the artificial design and standard genetic algorithm. The design efficiency is significantly improved as well. These improvements in the quality of design are further demonstrated by simulative experiments on the modified scale and characteristics of production orders.
2020 Vol. 55 (4): 53-59 [
Abstract
] (
522
) [
HTML
1KB] [
PDF
2800KB] (
717
)
60
SUN Ming-han, ZHU Zhi-wang, ZHENG Li-kang, ZHENG Chuan-xing, DU Feng-shan
Mechanism of oblique edge crack formation of cast-rolling strip
In order to improve the quality of cast-rolled strip products and reduce the risk of strip breakage caused by intrinsic cracks in the cast-rolling process. The oblique crack at the edge of the cast-rolled strip was studied to derive the formation mechanism of oblique crack in the edge:the heat exchange between the side seal and the molten pool makes the Kiss point height on the side of the pool locally elevated,leading to the local increase of the initial thickness of the thin strip in the plastic deformation stage of casting-rolling. Therefore,the oblique shear stress induced in the plastic deformation zone of the thin strip becomes the main reason for the formation of the oblique crack on the edge. A thermal-flow coupling numerical simulation model was established to analyze the distribution law of Kiss height along the width of the rollers in the molten pool. The results show that the Kiss point height on the edge of the pool is higher than that near the center of the pool. A thermally-mechanical coupling numerical simulation model was established to analyze the stress distribution in the plastic deformation zone of a thin strip with variable thickness during hot rolling. The shear stress analysis shows that the oblique shear stress is concentrated on the side of the backward slip zone in the plastic deformation zone,and its direction is consistent with the flow direction of the metal in the backsliding zone. A thermal-mechanical coupling numerical simulation model was established to analyze the stress distribution in the plastic deformation zone of the thin strip with a varying thickness during hot rolling. The analysis shows that the oblique shear stress is concentrated on the edge of the backward slip zone,and its direction is consistent with the flow direction of the metal there. The above simulation results verify the rationality of the formation mechanism.
2020 Vol. 55 (4): 60-67 [
Abstract
] (
483
) [
HTML
1KB] [
PDF
3489KB] (
628
)
Materials
68
WU Xiang-yu, HE Yu-dong, WU Liang-ping, SHEN Ping, FU Jian-xun
Effect of magnesium modification on sulfides in Y1Cr13 free-cutting stainless steel
In order to study the modification effect of magnesium on sulfides in Y1Cr13 free-cutting stainless steel,the distribution,morphology and precipitation conditions of sulfides in steel before and after adding magnesium are analyzed by metallographic microscope,Image-Pro Plus image analysis software,scanning electron microscope and FactSage thermodynamic software. The results showed that adding a finite amount of magnesium in the Y1Cr13 free-cutting stainless steel can change Al
2
O
3
into fine dispersed Al
2
O
3
·MgO,and the typical sulfides MnS in steel will precipitate with it as the core at 1 448 ℃,those formed MnS-Al
2
O
3
·MgO composite inclusions have internal soft and external hard structure. This structure makes MnS not easy to deform during rolling,and keeps spherical or ellipsoid shape in rolled products,and with the mass percent of magnesium,the precipitation temperature range of Al
2
O
3
·MgO will be larger,the precipitation amount will be more,and the improvement of MnS morphology will be more obvious. The sulfide grade decreased from fine line 5.5 and coarse line 4.5 before modification to fine line 3.5 and coarse line 1.0 after modification,and with the increase of its mass percent,the grade further decreased to fine line 2.5 and coarse line 0.5,and the rolling yield increased from 70% to 90%. Therefore,appropriately increasing the amount of magnesium is beneficial to improve its modification effect.
2020 Vol. 55 (4): 68-74 [
Abstract
] (
412
) [
HTML
1KB] [
PDF
2694KB] (
786
)
75
XIAO Shao-bin, WANG Wei, LIU Tian-yu, ZHANG Qin, LÜ Zhi-qing
Effects of vacancies and C atoms on mechanical properties of Fe grain boundary
In order to explore and characterize the deformation behavior of bcc-Fe grain boundaries from the nanoscale,the tensile and shear deformation processes of four different bcc-Fe Σ3 grain boundaries,i.e. Σ3(111),Σ3(112),Σ3(111)/(115) and Σ3(112)/(552),are investigated by molecular dynamics simulation. The effect of the vacancies and C atoms with different atomic percents on the machanical properties of the four different grain boundaries are discussed. The results indicate that the tensile stress-strain curve yield stage of Σ3(112) grain boundary gradually disappears due to the increase of the atomic percent of the grain boundary occupied by vacancies and C atoms.The tensile strength of Σ3(111)grain boundary gradually decreases with the increases of the atomic percent of vacancies,and the tensile strength of the other three grain boundaries are reduced in different degree. The tensile strength of Σ3(111) grain boundary containing C atoms increases,however,the other three grain boundary tensile strengths are lower than the original defect-free grain boundaries. The shear strength of the four grain boundaries is significantly reduced by the presence of vacancies or the replacement of C atoms.
2020 Vol. 55 (4): 75-81 [
Abstract
] (
528
) [
HTML
1KB] [
PDF
6256KB] (
602
)
82
XIAO Da-heng, TANG Wei, LUO Deng, WANG Zhen, XIE Zhen-jia, SHANG Cheng-jia
Microstructure and properties of low temperature steel for ultra large liquefied petroleum gas carrier
In order to meet the construction of ultra large liquefied petroleum gas carrier,the development of LT-FH32 low temperature steel for ultra large liquefied petroleum gas carrier with niobium and titanium composite microalloying,controlled rolling and controlled cooling technology were introduced. Microstructure evolution and mechanical properties were investigated systematically. Results from CCT curves suggested that when cooling rate was slower than 3 ℃/s,polygonal ferrite and pearlite was obtained in the studied LT-FH32 steel. While,multi-phase microstructure consisting of polygonal ferrite and bainite was obtained in wide range of cooling rate from 5 to 15 ℃/s. When cooling rate was 20 ℃/s,lath bainite was obtained. The developed LT-FH32 steel plates with 10 and 34 mm thickness consisted of polygonal ferrite and bainite. The two multi-phase microstructure steel plate exhibited similar mechanical properties from both sides of transverse and longitude. The yield strength was from 390 to 413 MPa,tensile strength was from 485 to 521 MPa,impact energy at -80 ℃ was higher than 200 J and DBTT was -100 ℃.
2020 Vol. 55 (4): 82-87 [
Abstract
] (
425
) [
HTML
1KB] [
PDF
6212KB] (
690
)
88
ZHUO Xiao, AN Tong-bang, MA Cheng-yong
Strengthening and toughening mechanisms of deposited metals for 420 MPa weathering bridge steel
The microstructure and mechanical properties of three kinds of deposited metals containing 3 different Si and Mn mass percent for 420 MPa grade weathering bridge steel were investigated. The effects of Si and Mn mass percent on the toughening and corrosion resistance of deposited metals were analyzed by scanning electron microscope (SEM),transmission electron microscope (TEM) and electrochemical measurement. The results showed that impact toughness of deposited metals was improved with the decrease of Mn and Si contents. When the Si mass percent was 0.32%,the strength of the deposited metal decreased by 5% and the impact energy was increased by 40%,accompanied with Mn mass percent decreased from 1.34% to 1.05%. When the Mn mass percent was 1.05%,the strength decreased by 2% and the impact energy was increased by 24% as the Si mass percent decreased from 0.34% to 0.20%. The increase of impact toughness was attributed to the decrease of the proportion of proeutectoid ferrites (including ferrite side plate) in the columnar and coarse grain reheated zone,and to the increase of acicular ferrites and the decrease of the size of M-A components that make the crack growth path more tortuous and the crack growth work increased. Further,the toughness and corrosion resistance were matched with the test steel as the self-corrosion potential difference between the deposited metals and the weathering steel was less than 20 mV.
2020 Vol. 55 (4): 88-94 [
Abstract
] (
437
) [
HTML
1KB] [
PDF
5597KB] (
685
)
95
LIU Qing-song, PEI Ying-hao, SHI Li-fa, XIA Xue-lan, HE Zhi-jian, CHENG Guo-qing
Effect of annealing tension on magnetic anisotropy of Fe-3.0%Si non-oriented silicon steel
In order to explore the effect of tension on magnetic anisotropy of high grade non-oriented silicon steel during annealing,the influence of unit tension on magnetic properties and magnetic anisotropy of Fe-3.0% Si non-oriented silicon steel during continuous annealing was simulated by MULTIPAS. The results show that the anisotropy of iron loss P
1.5/50
and magnetic induction B
50
increases from 10.50% and 1.72% to 11.11% and 1.84% respectively when the unit tension increases from 2 to 6 MPa;the lowest loss of silicon steel is 2.17 W/kg when the unit tension is 4 MPa;the better magnetic properties and iron loss anisotropy can be obtained when the unit tension is 3.16 MPa;and the anisotropy of silicon steel can be obtained during continuous annealing. The optimum unit tension should be controlled between 3 and 4 MPa.
2020 Vol. 55 (4): 95-99 [
Abstract
] (
443
) [
HTML
1KB] [
PDF
3383KB] (
736
)
Environmental Protection and Energy
100
WANG Jin-liang, DAI Xi, ZHANG Wei, GONG Shu-shan, ZHOU Guo-zhi, ZHANG Wen-hai
Advances of non-blast furnace flash iron-making researches
Non-blast furnace iron-making is one of the important directions to realize low carbon production in iron and steel industry. It has been studied for nearly a hundred years in foreign countries,and there are more than ten kinds of new processes,such as "direct reduction" and "melt reduction". However,it is a pity that blast furnace has not been successfully replaced so far,which shows that it is very difficult to innovate non-blast furnace iron-making technologies. The work and progress of the basic theory and experimental research of expanding the "flash metallurgy" process used widely in non-ferrous industry to iron-making were introduced,which is based on the thought of "interdisciplinary" between ferrous metallurgy and non-ferrous metallurgy. A non-blast furnace iron-making process characterized by "coal-based atmospheric gasification-suspended flash iron-making" was put forward,and the industrial design scheme and progress of the new iron-making process were also introduced.
2020 Vol. 55 (4): 100-105 [
Abstract
] (
786
) [
HTML
1KB] [
PDF
21580KB] (
610
)
Equipment Technology
106
ZHANG Yong-shun, JIANG Wan-lu, LI Zhen-bao, LI Jing-jing
Inducement analysis of nonlinear vibration in rolling mill hydraulic screw down system
The rolling mill with the hydraulic screw-down system is widely used in the strip production process, in order to solve the nonlinear vibration problem of rolling mill hydraulic screw-down system, the influence of three system parameters which are different damping coefficients, leakage coefficients and controller proportional coefficients on vertical vibration of the hydraulic screw-down system is studied under closed-loop control. Firstly, a vertical vibration model of the hydraulic screw-down system for the rolling mill is established considering the nonlinear spring force of the press cylinder. Secondly, the correlation between different system parameters and vertical vibration is analyzed by a vibration displacement-time diagram and a displacement-velocity phase diagram. Simulation results show that due to the hydraulic screw-down system of rolling mill adopts the traditional PID controller, the damping coefficient and leakage coefficient of the hydraulic system have slow time-varying characteristics, which may lead to the failure of the original PID control and cause vertical vibration of the system eventually. This research has a certain theoretical and practical engineering significance for the subsequent design of controllers to eliminate the vertical vibration caused by the fluctuation of hydraulic system parameters.
2020 Vol. 55 (4): 106-112 [
Abstract
] (
364
) [
HTML
1KB] [
PDF
1220KB] (
668
)
钢铁
News
·
·
·
·
·
More
Author Center
Instruction for Authors
Template
Copyright Agreement
Links
·
Links
More
Copyright © IRON AND STEEL
Supported by: Beijing Magtech
