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. 1
Published: 2020-01-15
Technical Reviews
Raw Material and Ironmaking
Steelmaking
Metal Forming
Materials
Technology Exchange
Technical Reviews
1
ZHANG Jun, YAN Ding-liu, QI Yuan-hong, SHEN Peng-fei, XU Hong-jun, GAO Jian-jun
Difficulty analysis on treatment and utilization of iron and steel smelting slag
In order to promote sensible heat recovery of smelting slag, reduce energy consumption in iron and steel smelting process, and improve utilization rate and economy of smelting slag, by analyzing the difficulties in the treatment and utilization of the molten slag in steel mills, a dry granulation method for molten slag based on the modification and foaming treatment is proposed, and the thermal conductivity as well as granulation of slag are improved by introducing metallic iron and foaming, which provides a way to solve the problems faced by the dry granulation and slag utilization. At last, some suggestions on the future research direction of dry granulation are given.
2020 Vol. 55 (1): 1-5 [
Abstract
] (
626
) [
HTML
1KB] [
PDF
932KB] (
7670
)
Raw Material and Ironmaking
6
LI Sheng, HE Zhi-jun, LI Yun-fei, QIU Shuang, ZHAN Wen-long, BAI Bing-yang
Metallurgical properties of furnace charge under different conditions of pellet ore and block ore addition
For the iron ore variety, quality, volatility of domestic steel enterprises resulting in a decline in blast furnace burden structure stability problem, through laboratory test, the system is studied on the metallurgical properties of iron ore, the high temperature properties of the comprehensive burden structure of the sinter and different kinds of natural lump ore, the sinter and pellet collocation and different kinds of natural ore and pellets. The results show that the reduction performance and the droplet property of sinter are better than that of acid pellets and imported block ore, but the low-temperature reduction degradation phenomenon is very serious, low temperature reduction degradation index RDI
>3.15 mm
is only 70%. Ha leather lump ore dripping temperature is too low, only about 1 353 ℃. The South Africa ore pressure difference is too large (6 820 Pa), which is not conducive to the stable and anterograde blast furnace. Due to the excellent metallurgical properties of Rio ball and samaco ball, the proportion of them can be appropriately increased in the production of the blast furnace to make up the shortage of sintering capacity and reduce the pollution to the environment. Under the condition of low sintering ratio (55%), using different pellet collocations, the burden of softening and melting interval is narrowed, the Δ
p
m
is lowered and the comprehensive performance is obviously improved. The best composite charge structure is 55% sinter +20% Rio pellet +5% Samaco pellet +20% Hopi block ore. With the addition of the new mixed ore burden structure, the soft melting range is narrowed, the Δ
p
m
and the
S
are lowered and the soft melt dripping performance is better.
2020 Vol. 55 (1): 6-11 [
Abstract
] (
569
) [
HTML
1KB] [
PDF
941KB] (
7164
)
12
DU Bin-bin, WU Sheng-li, ZHOU Heng, KOU Ming-yin
Effect of scaffolding on solid flow in COREX shaft furnace by discrete element simulation method
A three-dimensional DEM-based model was used to investigate the effect of scaffolding on the burden behavior such as the solid flow pattern and the interactive force in COREX shaft furnace. The improvement of the discharge rate on the solid flow under scaffolding conditions was also explored. The results confirm that the scaffolding occurred near the bustle pipe zone would directly affect the movement trajectory of the burden, resulting in the changes of solid flow pattern. Meanwhile, the interactive force was increased obviously compared to the normal condition. The solid flow pattern was also changed significantly when the scaffolding was generated in the guiding cone, and the particle segregation can be observed under the scaffolding. Comparing with the condition where scaffolding was generated near the bustle pipe zone, the interactive force was enhanced further. The force between the particles was decreased dramatically by increasing the speed of screw under the scaffolding, and the probability density distribution of interactive force shows a similar tendency as the normal condition. The findings of this work can provide guidance and theoretical basis for the optimized operation of COREX shaft furnace.
2020 Vol. 55 (1): 12-19 [
Abstract
] (
430
) [
HTML
1KB] [
PDF
11226KB] (
7968
)
Steelmaking
20
XI Xiao-jun, YANG Shu-feng, LI Jing-she, ZHAO Meng-jing, YE Mao-lin
Inclusion modification and corrosion resistance optimization of 304 stainless steel containing cerium
The evolution of inclusions in steel before and after the cerium treatment was studied by adding different amounts of cerium into the 304 stainless steel. And the effects of inclusion properties on corrosion resistance of 304 stainless steel were analyzed using the corrosion weight loss experiment and electrochemical experiment. MnS inclusions and composite oxide inclusions mainly existed in the stainless steel without cerium, and the average size of inclusions is 8.6 μm, while the self-corrosion potential of steel is only -348.52 mV. After the addition of cerium, the inclusions are gradually modified into spherical or elliptical inclusions, and the average size is reduced, while the corrosion resistance of stainless steel is improved. When the content of cerium reaches 0.012%, the MnS inclusions in steel are all modified into spherical inclusions containing cerium, and the corrosion potential of stainless steel is as high as -311.25 mV, which has the best corrosion resistance. As the content of cerium continues increasing, the shape of the inclusions in steel becomes irregular, and the size of inclusions also increases, resulting in a decrease in the corrosion resistance of the stainless steel.
2020 Vol. 55 (1): 20-26 [
Abstract
] (
497
) [
HTML
1KB] [
PDF
1843KB] (
6518
)
27
LI Bai-song, CHEN Wen-zhi, YAO Shu-fang, ZHAO Yu-lin
Source and formation mechanism of inclusions in FeSiB amorphous ribbon
In order to formulate a reasonable inclusion control process to improve the quality and magnetic properties of FeSiB amorphous ribbon, the source and the formation mechanism of inclusions were analyzed. The results show that the spherical and elliptical inclusions consisted of Al
2
O
3
and SiO
2
mainly come from the industrial pure iron. During the next smelting process, ellipsoidal inclusions of 20-30 μm in the pure iron were removed by floatation, while spherical inclusions of 1-3 μm combined with the deoxidized products and form aluminum silicate inclusions and aluminum calcium silicate inclusions in FeSiB master alloy. Some of these inclusions accumulated in the inner wall of the nozzle during the spraying process, while the other parts of inclusions flowed out of the nozzle and remained in the FeSiB amorphous ribbon.
2020 Vol. 55 (1): 27-33 [
Abstract
] (
492
) [
HTML
1KB] [
PDF
33312KB] (
6623
)
34
YIN Chuan-lei, YANG Li-mei, TIAN Chun-yang, MA Jian-chao
Analysis of KR hot metal desulfurizer escaped and slag agglomeration in agitator
In order to further improve the hotmetal desulfurization efficiency by the KR mechanical stirring,the escape of desulfurizer in the process of hotmetal desulfurization by the KR mechanical stirring and the slag block on the upper blade of the agitator were analyzed. The results show that the particle size and composition of desulfurizer, the feeding mode, and slag from hot metal are the main reasons for the additive escape and the slag agglomeration in the agitator. By controlling the proportion of desulfurizer particle size <0.1 mm to less than 10%, controlling the stirring speed during feeding at ≤40 r/min, optimizing the size of fluorite to avoid high local CaF
2
content in desulfurizer and removing slag from hotmetal before desulphurization, which can effectively improve the desulfurizer escape and the slag agglomeration in the agitator, thereby improving the utilization rate of desulfurizer and desulfurization rate of hot metal.
2020 Vol. 55 (1): 34-37 [
Abstract
] (
301
) [
HTML
0KB] [
PDF
1716KB] (
445
)
38
CHU Yan-ping, CHEN Zhi-yong, LIU Nan, ZHANG Li-feng
Formation and control of spinel inclusions in high-speed heavy rail steel
Large particles of pure MgO-Al
2
O
3
inclusions are often found in high-speed heavy rail steel, which affects the quality of products seriously. To clarify the source of spinel inclusions in high-speed heavy rail steel for better inclusion controlling, the formation mechanism of spinel inclusions in high-speed heavy rail steel is systematically studied through tensile fracture analysis, combined with nozzle clogging analysis, thermodynamic calculations and typical inclusion analysis. The results show that the spinel inclusions in the steel can be classified into two types: single spinel inclusions and spinel inclusions wrapped by calcium aluminate. The spinel inclusions wrapped by calcium aluminate is caused by the self-precipitation of CaO-SiO
2
-Al
2
O
3
-MgO composite inclusions during the cooling process, and the precipitation temperature is related to the content of Al
2
O
3
and MgO in inclusions; smaller single spinel inclusions in the steel are precipitated during the solidification and cooling process, which depends on the chemical composition of the steel. In addition, the study also shows that nozzle nodulation is one of the important reasons for the occurrence of larger spinel inclusions in heavy rail steel. Therefore, strictly controlling the content of impurity elements such as Mg and Al
s
in alloys and raw materials, preventing secondary oxidation, and reducing the corrosion of refractories and the content of Al
2
O
3
, MgO in inclusions as much as possible are very important for controlling spinel inclusions and improving products quality.
2020 Vol. 55 (1): 38-46 [
Abstract
] (
528
) [
HTML
1KB] [
PDF
19529KB] (
834
)
Metal Forming
47
YI Ya-li, HAN Xiao-kai, ZHANG Lei, JIN He-rong
Homogeneity of grain structure for 316L/EH40 stainless steel clad plate during hot rolling process
In order to improve the uniformity of the grain structure of the hot-rolled stainless steel clad plate, the numerical simulation scheme was designed by the orthogonal experimental optimization design method. The effects of rolling parameters on the non-uniformity factor of the base, the average grain size of the base, the non-uniformity factor of clad and the average grain size of the clad were studied, and the order of the significant effects of each parameter was analyzed. The comprehensive equilibrium method was used to obtain the optimum scheme. Optimum parameters were, the rolling reduction rate is 60%, the blooming temperature is 1 100 ℃ and the rolling rate is 300 mm/s. The optimized parameters were simulated by the finite element method, and the distribution and the variation of the grain size along with the thickness direction of the stainless steel clad plate during the hot rolling were obtained. By comparing the grain size obtained by experiments and simulations, the error of the grain size is less than 5%, which verifies the correctness and reliability of the finite element model.
2020 Vol. 55 (1): 47-55 [
Abstract
] (
347
) [
HTML
1KB] [
PDF
20674KB] (
503
)
56
BAI Zhen-hua, CUI Ya-ya, LI Xiu-jun, XIA Yi-wei
Development of emulsion pipeline direct mixed lubrication system in double cold reduction mill
The traditional direct application system can only online adjusting the emulsion flow,but cannot online adjusting the emulsion flow and concentration simultaneously,resulting in the rolling instability,poor strip thickness and flatness quality,high rolling energy and oil consumption cost during the steel grade change,rolling acceleration and deceleration in the double cold reduction mill. Combing with the equipment and technological characteristics of the double cold reduction mill,the key equipment of the emulsion pipeline direct mixed lubrication system was optimizing selected on the developed experimental platform. Thus,the design method of the emulsion pipeline direct mixed lubrication system in the double cold reduction mill was proposed. Moreover,the emulsion properties of the mixing tank agitation and the pipeline direct mixing were compared. Then,this lubrication system was applied in a 1 220 double cold reduction mill,with the rolling stability,strip thickness,flatness quality effectively improved,and the rolling energy and oil consumption cost reduced.
2020 Vol. 55 (1): 56-64 [
Abstract
] (
362
) [
HTML
0KB] [
PDF
9001KB] (
280
)
65
TANG Wei, DU Feng-shan, LIN Hai-hai, WEN Jie
Control technology of cold rolled high-strength container plate′s rolling stability
The cold rolled high-strength container plate′s high requirement for its yield strength,forming property and dimensional accuracy has posed great challenges to the rolling stability and the shape control of cold rolling. The ribbed wave and the edge crack in the productive process of cold rolled high strength container plates were analyzed. The influence of the cooling process of the hot rolled strip area on the homogeneity of temperature and performance was studied through experiments. The strip′s deformation features in the process of UCM cold rolling was studied by FEM,the concurrent mechanism of wave shape and edge crack was developed,and the influence of different processes on the deformation homogeneity of the strip was analyzed. Combining theory and FEM,the optimization scheme for the performance homogeneity of the hot roller and the rolling stability of the coll rolling was presented. The shape quality of the cold rolled sheet is obviously improved and the edge crack defect of the strip is completely eliminated after the improvement. The rolling stability and product quality of cold rolled high strength container plates have been greatly improved.
2020 Vol. 55 (1): 65-71 [
Abstract
] (
312
) [
HTML
0KB] [
PDF
5091KB] (
327
)
Materials
72
GUAN Zhen, SUN Yong-qing, LI Li, TIAN Shuai, LIU Zhen-bao, LIANG Jian-xiong
Effects of smelting process on fatigue performance of 15-5PH stainless steel
In order to study the effect of smelting processs on the fatigue properties of 15-5PH stainless steel,the effects of smelting process on the particle size distribution and fatigue properties of inclusions in 15-5PH stainless steel were studied by ASPEX inclusion analysis,tensile fatigue test,scanning electron microscopy and crack growth rate experiments. The crack growth rates of the two test steels were also compared. The results showed that No.1 test steel smelted by VIM+VAR process had lower total oxygen mass percent,smaller inclusion size and less mass percent. The fatigue strength of No.1 test steel was 30 MPa higher than that of No.2 test steel smelted by single vacuum process. By means of SEM observation of fatigue fracture,No.1 test steel cracked on the surface matrix,and the crack source of No.2 test steel was subsurface Al
2
O
3
inclusion. Under the same conditions,the crack growth rate of No.1 test steel was faster than No.2 test steel.
2020 Vol. 55 (1): 72-80 [
Abstract
] (
307
) [
HTML
0KB] [
PDF
17007KB] (
305
)
81
LIU Hai-tao, WANG Jian, YANG Zheng-yuan, YIN Bao-shu, ZHANG Jia-de, ZHANG Gao-xiang
Effect of bismuth element with low melting point on embrittlement behavior of steel
In order to prove the "two-sidedness" effect of low melting point elements bismuth during the machining and the high temperature deformation processes in the steel,the influence of bismuth on the embrittlement behavior of steel in different temperature ranges was studied by the cutting experiment,high temperature thermoplastic experiment and microstructure analysis. The results showed that embrittlement of steel by bismuth in the cutting process can promote the formation of "C-shaped" brittle chips and make bismuth free-cutting steel having an excellent machinability. This embrittlement behavior was mainly associated with the liquid metal embrittlement of bismuth in steel,which significantly reduced the plastic of steel at bismuth liquidus temperature. The influence of bismuth on the embrittlement behavior of steel during high temperature deformation was mainly related to the segregation of bismuth film at the austenite grain boundary,which endangered the grain boundary strength of steel,and then significantly reduced the thermoplastic behavior of steel at the experimental temperature range of 1 000 ℃ and below.
2020 Vol. 55 (1): 81-85 [
Abstract
] (
433
) [
HTML
0KB] [
PDF
17902KB] (
366
)
86
YANG Ji-chun, WANG Jun, REN Lei, FU Xiao-yang, LIU Xiang-jun, ZHANG Ze-ning
Effect of Ce on microstructure and impact propertiesof S32550 duplex stainless steel
Duplex stainless steel has excellent properties of austenitic and ferritic stainless steel,which is widely used in shipbuilding,chemical industry,nuclear reaction and other fields. In order to further improve the mechanical properties and corrosion resistance of S32550 duplex stainless steel,S32550 duplex stainless steel was successfully smelted with vacuum induction furnace first. Furthermore,the effects of rare earth Ce on the microstructure,inclusion morphology and impact properties of the alloy after forging and rolling were studied. The results show that the addition of rare earth Ce can refine the grain of the structure and homogenize the strontium ferrite structure and the austenite structure with uneven shape distribution,improve the shape distribution of inclusions,modify the harmful inclusions MnS,reduce the S content,and make the excess S element react with Ce to form Ce
2
O
2
S,Ce
2
S
2
inclusions dispersed in steel.In addition,the addition of rare earth Ce can improve the impact toughness of S32550 duplex stainless steel under the impact of room temperature and low temperature (-40,-20 ℃). At low temperature,the dimple zone can appear,which reduces the damage of steel to cold and brittle effect.
2020 Vol. 55 (1): 86-92 [
Abstract
] (
359
) [
HTML
0KB] [
PDF
31746KB] (
289
)
93
ZHOU Liu-tao, PAN Hong-bo, PAN Shuo, WU Jie-wen
Effect of annealing process on microstructure texture and mechanical properties of 0.025C-0.326Mn steel
In order to optimize the strength and deep drawability of low alloy steel,continuous annealing and salt bath annealing+over-aging process were adopted in this experiment. The effects of annealing temperature and over-aging temperature on microstructure,texture evolution and mechanical properties of 0.025C-0.326Mn steel were investigated. The results show that the increase of annealing temperature promotes the transformation of α texture to γ texture. The dispersed distribution of fine carbide particles hinders grain rotation,resulting in the re-emergence and increase of {113}<110> oriented grains,affecting the genetic evolution of {111} surface texture. The over-aging process promotes the precipitation of solid solution carbon in the ferrite after annealing,and purifies the ferrite. The increase in over-aging temperature improves the elongation of the material,wherein the elongation is preferably up to 36.9%. The
r
value of the continuous annealing sample is preferably 1.26,however,the salt bath annealing and over-aging process increases the
r
value to 1.39,and the latter tensile strength meets the requirements of 500 MPa grade.
2020 Vol. 55 (1): 93-100 [
Abstract
] (
373
) [
HTML
0KB] [
PDF
14459KB] (
391
)
101
ZHOU Yun, YANG Xiao-wei, CHEN Huan-de, ZHANG Yu
Effect of heating temperature on microstructure and properties of 600 MPa grade high strength steel rebars
In order to achieve the industrial application of high strength steel rebars,Nb-V microalloyed 600 MPa grade steel rebars were set as studied object,effect of heating temperature on grain growth was studied by confocal laser scanning high-temperature microscope,and plant trial was conducted. The result shows that increasing heating temperature leads to increasing austenite grains.When the heating temperature changes from 1 180 ℃ to 1 270 ℃ and the soaking time is 60 min,the average austenite grain size improves from 58.7 μm to 85.1 μm. When the heating temperature is improved to 1 270 ℃,the average austenite grain size increases to 77.8 μm. In plant trial,with the heating temperature increases from 1 200 ℃ to 1 270 ℃,the proportion of pearlite and the size of the pearlite colony increases,the tensile fracture morphology changes from ductile fracture to quasi-cleavage brittle fracture. While heating at 1 200-1 250 ℃ can produce a steel rebars with a yield strength of 640-659 MPa,a tensile strength of 823-846 MPa,a yield ratio of 1.28-1.30,a elongation rate of 16.6%-19.2%,a maximum force elongation of 10.6%-13.0%.
2020 Vol. 55 (1): 101-107 [
Abstract
] (
508
) [
HTML
0KB] [
PDF
29141KB] (
629
)
Technology Exchange
108
HAN Yi, XIAO Yao, ZHANG Ao-yin, ZHAO Yu-fei, LIU Feng, LI Hong-bin
Recessive defects in electromagnetic heating process of electrical resistance welding steel pipe
With the rapid development of Chinese steel industry and electromagnetic metallurgy technology,the welded pipe industry has developed rapidly and the quality of welded steel pipes has been continuously improved. However,the electromagnetic metallurgy technology is difficult to avoid the inherent skinning and proximity effects,resulting in product defects that limit the wide application of welded steel pipes in harsh environments such as the deep sea,polar,and high pressure. In order to improve the safety service of steel pipes, a new method to analyze hidden defects by means of precision heating technology was propesed. The two processes of welding and heat treatment of steel pipes were carried out as a whole for comparative analysis. It was found and quantitatively explained that there is a hidden defect inside the steel pipe which is different from the conventional heating defects. The defect area ratio is given as the quantitative index for evaluating the hidden defects, and the influence law of the tube blank production speed on various hidden defects is analyzed. When the billet moving speed is in the range of 55-65 mm/s,the area defect rate tends to be gentle; when the speed is too high,the area defect rate increases rapidly; when the speed is too low,the heating repeat area causes energy loss that should not be neglected. The research has certain positive significance for improving the reliability of welded pipes in harsh environments and promoting the green development of steel manufacturing.
2020 Vol. 55 (1): 108-118 [
Abstract
] (
379
) [
HTML
0KB] [
PDF
19529KB] (
297
)
钢铁
News
·
·
·
·
·
More
Author Center
Instruction for Authors
Template
Copyright Agreement
Links
·
Links
More
Copyright © IRON AND STEEL
Supported by: Beijing Magtech
