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Steelmaking 2021 Vol.37 Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Study on the dynamic characteristics of gas-solid mixed injection in steelmaking process Steelmaking    2021, 37 (1): 1-7.   Abstract （76）            Knowledge map    Save Related Articles | Metrics Select Research and application of CO2 bottom blowing in a 120 t converter Steelmaking    2021, 37 (1): 8-13.   Abstract （74）            Knowledge map    Save Related Articles | Metrics Select Mechanism analysis and production practice of high efficiency dephosphorization of V-Ti hot metal in 100t BOF Steelmaking    2021, 37 (1): 13-22.   Abstract （74）            Knowledge map    Save Related Articles | Metrics Select Research on titanium-containing molten iron converter smelting and its pre-detitanium behavior Steelmaking    2021, 37 (1): 23-26.   Abstract （43）            Knowledge map    Save Related Articles | Metrics Select Study on the variations of cleanliness and inclusions in low oxygen high-carbon-chromium bearing steel during LF-VD refining process Steelmaking    2021, 37 (1): 27-32.   Abstract （43）            Knowledge map    Save Related Articles | Metrics Select Evolution mechanism of inclusions during LF refining process of GCr15 bearing steel Steelmaking    2021, 37 (1): 33-38.   Abstract （60）            Knowledge map    Save GCr15轴承钢；LF精炼；D类夹杂物；演变机理 Related Articles | Metrics Select Application of carbon-oxygen equilibrium in RH soft-treating process for low carbon and low silicon steel Steelmaking    2021, 37 (1): 39-43.   Abstract （54）            Knowledge map    Save Related Articles | Metrics Select Overview of formation mechanism and control technology of hooks in continuous casting slab Steelmaking    2021, 37 (1): 44-56.   Abstract （86）            Knowledge map    Save Related Articles | Metrics Select Analysis and optimization of secondary cooling uniformity of slab continuous caster Steelmaking    2021, 37 (1): 57-62.   Abstract （48）            Knowledge map    Save Related Articles | Metrics Select Analysis and optimization of influencing factors in four-strand tundish flow field Steelmaking    2021, 37 (1): 63-72.   Abstract （51）            Knowledge map    Save Related Articles | Metrics Select Inclusion analysis and process optimization of axle steel EA1N Steelmaking    2021, 37 (1): 73-80.   Abstract （42）            Knowledge map    Save Related Articles | Metrics Select Characteristic and control of hooks at the subsurface of low-carbon and ultra-low carbon steel continuous casting slab Steelmaking    2021, 37 (2): 1-9.   Abstract （161）            Knowledge map    Save The hook structure at the subsurface of low carbon steel and ultra-low carbon steel continuous casting slab was studied, the typical morphology of hook was obtained. The entrapment of bubbles and inclusions by hooks was observed, and the location relationship between oscillation marks and inclusions was obtained. The influence of different casting parameters on hook depth was compared through the experimental method and numerical simulation, and the regression formula was fitted to calculate the hook depth. It was found that types of hooks included whole leaf-like type, bent type, double-hook type and truncated type. The entrapment tendency of over 20 μm inclusions by hooks was larger. The depth of hooks was mainly below 3.0 mm from the surface of the continuous casting slab, and the increase of casting speed and casting superheat, the application of EMBr and the decrease of water flow rate in the mold could lead to the decrease of hook depth at the subsurface of continuous casting slab, which then improved the surface quality of the slab. Related Articles | Metrics Select Prediction model of phosphorus content in dephosphorization converter end point based on BP neural network algorithm Steelmaking    2021, 37 (2): 10-15.   Abstract （176）            Knowledge map    Save In order to predict more accurately the phosphorus content of molten steel at the end of dephosphorization converter smelting，DC04 steel was selected as the research object by smelting in a steel company. According to the process parameters of hot metal conditions, slagging materials, oxygen blowing amount and the like obtained by industrial tests, the grey correlation degree of each process parameter on the end-point phosphorus content of the dephosphorization converter was obtained by using the grey correlation analysis method, and a prediction model on the end-point phosphorus content of the dephosphorization converter smelting was established by combining the BP neural network algorithm. Through continuous optimization of the model, when the end point w(P) error of dephosphorization converter was ±0.004 %, ±0.006 % and ±0.008 %, the hit rate reached 83.33 %, 90.00 % and 93.33 %, respectively. The application of this model in the field can provide technical reference for iron and steel enterprises to determine the end point phosphorus content more accurately and quickly. Related Articles | Metrics Select Composition evolution of inclusions in 316L stainless steel refining process Steelmaking    2021, 37 (2): 16-22.   Abstract （160）            Knowledge map    Save Steel samples were taken at the AOD process, LF refining, and slab during the production of 316L stainless steel. The mass fraction of total oxygen and nitrogen,the number density, and composition of inclusions in steel samples were analyzed. The mass fraction of total oxygen in the steel gradually deceased and reached 24×10-6 after calcium treatment,183×10-6 lower than that at the end of AOD reduction. Reoxidation occurred during continuous casting and the total oxygen mass fraction in the slab was increased by 8×10-6. At the end of AOD reduction,the inclusions were mainly SiO2-MnO. The inclusions were divided into the CaO-Al2O3-SiO2 system and the CaO-Al2O3-MgO system at LF arrival. The former was mainly generated by the reaction between the entrained AOD slag and dissolved aluminum in the steel, and the latter was mainly formed by the reaction between the SiO2-MnO inclusions, dissolved aluminum and slag phase. ForCaO-Al2O3-SiO2 system, the average composition of inclusions at LF arrival was not in the low melting temperature region.With the progress of LF refining,the content of CaO decreased and the content of Al2O3 increased in inclusions. Its average composition was in the low melting temperature region. For the CaO-Al2O3-MgO system, the content of MgO increased and the number of MgO·Al2O3 spinel inclusions increasd. After calcium treatment and holding process, there were no CaO-Al2O3-MgO inclusions in the steel, indicating that the inclusion modification was relatively appropriate. Related Articles | Metrics Select Study on titanium alloying technology during the refining of ferritic stainless steel containing titanium Steelmaking    2021, 37 (2): 23-29.   Abstract （64）            Knowledge map    Save Based on the plant trials and thermodynamic calculation，the titanium alloying of ferritic stainless steel containing titanium during the reduction process of VOD，the early stage of LF and the late stage of LF and its influence on the quality of molten steel were investigated. The results showed that the closer the time of titanium alloying is to the end of refining，the higher the titanium yield was. The titanium yield of 409L steel was 62.7 % after VOD reduction，while the yield of titanium alloy was 76 % at the later stage of LF refining. The total oxygen content and the pouring property of steel were also affected by the titanium alloying. The closer it was to the end of refining，the higher the total oxygen content in the steel was and the higher the increase ratio of the plunger position in the casting process was. The oxidizability of molten steel could be reduced and the yield of titanium could be increased by controlling the slag amount from K-OBM-S，weak oxide（Cr2O3+MnO+TFe）content in the slag，VOD oxygen blowing and increasing the total aluminum mass fraction in the steel. The mass fraction of total oxygen in molten steel could be reduced and the pouring property of steel was improved when titanium alloying in the early stage of LF refining. Related Articles | Metrics Select Calculation method of stress analysis during soft reduction of continuous casting Steelmaking    2021, 37 (2): 30-36.   Abstract （96）            Knowledge map    Save The soft reduction process in continuous casting was investigated. The mechanical equilibrium equation was derived for each finite element in slab. Furthermore, the stress and deromation during soft reduction were analyzed by combining the temperature distribution of slab. Results indicate that, the stress on the edge of slab is higher than that on the center of wide face, and the maximum value exceeds 100 MPa. With the proceeding of reduction, the stress on the surface of slab decreases. For the center of slab, the stress and the deformation increase during reduction.When the total reduction amount is given, the deformation on the center of slab is almost independent with the steel grade and the reduction position. However, the steel grade and the reduction position have an important effect on the stress. During soft reduction, the force exerted on stainless steel is much higher than that on general carbon steel at the position with a fixedd solid fraction, and the value increases when approaching the end point of solidification. Related Articles | Metrics Select Review on mechanism and control technology of transverse corner crack in continuous casting slab of peritectic steel Steelmaking    2021, 37 (2): 37-46.   Abstract （103）            Knowledge map    Save Transverse corner crack is the most prominent quality problem in the continuous casting process of peritectic steel. In this paper, the mechanism and control technology of corner transverse crack in peritectic steel were reviewed. The peritectic and hypoperitectic steels with carbon mass fraction ranging from 0.08 % to 0.18 % are very sensitive to cracks because of the transformation from δ phase to γ phase during the solidification process of molten steel. At the same time, the temperature for the formation of γ phase is higher, and the original austenite grains are easy to grow, so they are very sensitive to cracks. For peritectic and hypoperitectic steels containing Nb, Al and V, the second phase particles such as Nb, Al and V are easy to precipitate in the proeutectoid ferrite film of the original austenite grain boundary, which further reduces the high temperature plasticity of the steel, resulting in the occurrence of transverse corner cracks.When the thickness of proeutectoid ferrite film is more than 5 μm, the reduction of area and the plasticity of steel decrease, which is easy to cause cracks.The control technology of corner transverse crack in continuous casting slab of peritectic steel includes optimization of liquid steel compositions, mold vibration, secondary cooling conditions, chamfering mold, mold powder performance, and maintaining good equipment status of continuous caster. Related Articles | Metrics Select Study on narrow composition control technology of high strength automobile board Steelmaking    2021, 37 (2): 47-50.   Abstract （62）            Knowledge map    Save Through the study of LF+RH process and chemical composition of high strength steel, in view of the key problems of C,Mn ,S content and slag composition ,based on the analysis of the reasons for the failure of narrow composition control, the theory and practical operation mode of narrow composition control were put forward. Through practical operation, the qualified rate of C, Mn, S content in the narrow range of composition can reach more than 95 %, and can be stably controlled. After controlling the narrow composition of C,Mn and S elements, the fluctuation range of tensile strength of high-strength steel can be reduced by 30-70 MPa, and the strength, toughness and mechanical propeities of highstrength steel can be improved. Related Articles | Metrics Select Study on inclusion controlling of thin gauge high strength steel by CSP process Steelmaking    2021, 37 (2): 51-57.   Abstract （47）            Knowledge map    Save In order to improve the cleanliness and reduce the cost of thin gauge high strength steel in CSP process, the change of the cleanliness of molten steel and the morphology, the size and the compositions of inclusions in WJX600 steel during refining were studied by industrial experiments. The industrial results showed that, the amount of calcium wire feeding had little influence on T.O of molten steel, the  T.O mass fraction of molten steel in tundish was less than 0.002 5 %, and nitrogen mass fraction was less than 0.004 %. The ratio of the inclusions with the size more than 10 μm increased with the amount of calcium wire feeding. The principles and the aim for inclusion modification by calcium were given by analysis. The judgement-changing rate of thin gauge high strength steel decreased to 0.48 % from 1.2 % by light calcium treatment and optimization of refining process. Related Articles | Metrics Select Crystallization behavior of glassy inclusions in Si-killed spring steel 55SiCr during bloom and billet heating Steelmaking    2021, 37 (2): 58-61.   Abstract （67）            Knowledge map    Save The bucket-shaped samplers of Si-killed spring steel 55SiCr after LF refining were heated with bloom before blooming and billet before hot rolling respectively. And the morphology and composition changes of oxide inclusions before and after heat treatment were detected by FEI Explorer 4 automated scanning electron microscope. The results show that some crystalline phases appears on the glassy inclusions in both cases. When the holding temperature is kept at 1 250 ℃ for about 2.5 h, the crystalline phase is coarse and the crystallization position has penetrated through the whole inclusions. In contrast, when the holding temperature is kept at 1 020 ℃ for about 0.5 h, the crystallizing size is small, and the crystallization position of large particle mainly occurs at the edge of inclusions. Related Articles | Metrics Select Changes of inclusions composition in the EH36 ship plate steel during production process Steelmaking    2021, 37 (2): 62-69.   Abstract （45）            Knowledge map    Save The inclusions of EH36 ship plate steel produced by “BOF→LF→RH→CC” process were studied. The morphology and composition of inclusions in the sample were analyzed by SEM-EDS，and the precipitation of inclusions were calculated by Factsage software. The research showed that inclusions were mainly SiO2 when the molten steel was hoisted into LF furnace，and MnS of the sample was formed during solidification of the sample. The number of liquid inclusions was increased after calcium treatment. Al2O3 content of inclusions was increased and the content of CaO and MgO were decreased after RH refining. Al2O3 content of inclusions was decreased and CaO content of inclusions was increased in tundish. The composition of inclusions was close to the low melting point zone due to the inclusions reacting with slag. SiO2 content of slag was high and it reacted with Al of molten steel，which caused to increase Si content and reduce Al content in the molten steel. Because composition segregation occurred during solidification of molten steel，S content of inclusions was significantly increased，Al2O3 content of inclusions was increased and CaO content of inclusions was decreased. Calcium aluminate inclusions with different ratios of CaO and Al2O3 and Al2O3 inclusions were formed in the billet，and CaS was formed on the surface of some calcium aluminate. Related Articles | Metrics Select Study on the heredity of metallurgical defects on the surface of cold-rolled plat Steelmaking    2021, 37 (2): 70-78.   Abstract （54）            Knowledge map    Save The influence of mould level fluctuation, scarfing depth on the surface quality of hot rolled coil were analyzed by tracking the whole process of steelmaking, hot rolling and cold rolling，and the heredity of defects on the cold coil was studied. The results show that the defects of steelmaking contain four categories, such as mold powder entrapment, cluster Al2O3, blisters and blisters+Al2O3. The occurrence rate of the defects of the mold powder entrapment with the fluctuation of the mould liquid level ≥5 mm on the hot-rolled coil is 100 %. The part of mold powder entrapment can be eliminated after pickling, which will not affect the surface quality in the subsequent rolling process. The mold powder entrapment with spills and the spills have good heredity on the cold-rolled coil, which not be eliminated through pickling , rolling and galvanizing. According to the above statistical analysis, on the one hand, the optimization of the process parameters during casting for the high-level automobile outer panel was provided. The control window of steel-making process parameters of automobile outer plate production was put forward. On the other hand, the standard for releasing the defects without heredity was determined according to the customer requirements. Related Articles | Metrics Select Research on manganese oxidation in the process of converter steelmaking Steelmaking    2021, 37 (3): 1-9.   Abstract （192）            Knowledge map    Save Related Articles | Metrics Select Industrial test of highintensity bottom blowing CO2 in 120 t combined blowing converter Steelmaking    2021, 37 (3): 10-16.   Abstract （74）            Knowledge map    Save Related Articles | Metrics Select Experimental study on the interaction between limestone and carbon in molten iron Steelmaking    2021, 37 (3): 17-21.   Abstract （91）            Knowledge map    Save Related Articles | Metrics Select Molten steel image segmentation method based on level set Steelmaking    2021, 37 (3): 22-28.   Abstract （72）            Knowledge map    Save Related Articles | Metrics Select The influence of wettability on gasliquid two phase flow in RH refining Steelmaking    2021, 37 (3): 29-38.   Abstract （72）            Knowledge map    Save Related Articles | Metrics Select Analysis and control method of slag crusting for LF deep desulfurization refining Steelmaking    2021, 37 (3): 39-43.   Abstract （88）            Knowledge map    Save Related Articles | Metrics Select Mechanism and improvement of erosion of stopper rod during continuous casting process of highstrength lowalloy steel after calcium treatment Steelmaking    2021, 37 (3): 44-50.   Abstract （134）            Knowledge map    Save Related Articles | Metrics Select Research on causes and control of central cracks in large section continuous casting round billets Steelmaking    2021, 37 (3): 51-57.   Abstract （88）            Knowledge map    Save Related Articles | Metrics Select Effect of selective crystallization on slab surface cracks during continuous casting of peritectic steel Steelmaking    2021, 37 (3): 58-61.   Abstract （117）            Knowledge map    Save Related Articles | Metrics Select Analysis of the phase and formation of the attachment on the inner wall of magnesiumcarbon SEN for the cord steel Steelmaking    2021, 37 (3): 62-65.   Abstract （72）            Knowledge map    Save Related Articles | Metrics Select Effect of tellurium on the sulfide and machinability of free cutting steel Steelmaking    2021, 37 (3): 66-73.   Abstract （112）            Knowledge map    Save Related Articles | Metrics Select Study on mechanism and optimization of cone fracture of SWRH82B prestressed steel strand Steelmaking    2021, 37 (3): 74-80.   Abstract （107）            Knowledge map    Save Related Articles | Metrics Select Production practice of rapid reduction of bottom height in 65 t top-bottom combined blowing converter Steelmaking    2021, 37 (4): 1-4.   Abstract （119）            Knowledge map    Save In view of the problem of bottom height rising of 65 t top and bottom combined blown converter in Masteel, the causes were analyzed and some solutions were proposed. Production practice showed that,by using the reaction of molten iron and oxygen,the height of converter bottom could be reduced rapidly by controlling the lance position, oxygen accumulation and erosion time. The splash rate decreased from 0.63 % to 0.31 % due to blowing difficulty caused by converter bottom exceeding upper limit, and ferrous charges consumption was reduced by 4.16 kg/t, which provided a strong guarantee for converter steelmaking production safety. Related Articles | Metrics Select Experiment on high efficient conditioning treatment of ladle slag in production of ULC automobile sheet steels Steelmaking    2021, 37 (4): 5-9.   Abstract （81）            Knowledge map    Save In the ladle slag conditioning treatment after BOF tapping in production of automobile sheet steel, measures must be taken to prevent the reaction between the high [O] content liquid steel and the top slag in addition to add enough amount of conditioning agent. Otherwise, the mass fraction of FetO in the slag will rise back to 8 %-14 %, or even higher, though it can be lowered to low content level temporally in conditioning treatment. The technology developed by Hanbao Steelmaking Plant of Hansteel Co., Ltd. to restrain the slag-steel reaction in ladle slag conditioning treatment is introduced in this article, which are 1) using aluminum-slag pellets as the slag conditioning agent which can slowly release Al in and after the conditioning treatment, 2) adding lime after BOF tapping instead of during tapping, 3) increasing ratio of w(CaO)/w(Al2O3) of the ladle slag to lower its fluidity,and 4) using week bottom stirring. With the developed technology, TFe mass fraction of the ladle slags before and after RH refining is lowered to less than 3 % and 5 %, respectively. Re-oxidation of the molten steel due to the ladle slag has been controlled. Contents of the total oxygen and non-metallic inclusions of the liquid steel in CC tundish are reduced and nozzle clogging in continuous casting has been effectively controlled. Related Articles | Metrics Select Production practice of reducing power consumption of 120 t LF refining furnace Steelmaking    2021, 37 (4): 10-15.   Abstract （104）            Knowledge map    Save Aiming at the problem of high power consumption in LF refining of a certain plant，the influencing factors of refining power consumption were analyzed．The optimization improvement measures such as composite reflection heat insulation board were adopted to improve the thermal insulation performance of ladle，optimizing the empty ladle time of on-line ladle and upgrading ladle baking system of oxy-fuel to increase temperature drop of ladle lining，increasing slag return in hot state of continuous casting and reducing the exposed area of molten steel in refining process were adopted．The production practice of reducing refining power consumption was also carried out．The temperature of molten steel in the production process was reduced by 28.17 ℃．The refining power consumption has been reduced from 45.14 kWh/t before improvement to 35.58 kWh/t at present，with an average reduction of 9.56 kWh/t，saving about 4.78 yuan per ton of steel refining cost.  Related Articles | Metrics Select Effect of nozzle port angle with wide range change on flow field in slab continuous casting mold with large width Steelmaking    2021, 37 (4): 16-24.   Abstract （100）            Knowledge map    Save The velocity near the mold surface was measured with the rod deflection method under the condition cross-section width of 2 000 mm and the angle of nozzle of 15°, 20° and 45° respectively. The influence of nozzle port angle on the flow field of molten steel in the mold was also analyzed by numerical calculation. With increasing the nozzle port angle from 15° to 20° and 45°, the velocity near the mold surface decreased from 0.4 m/s to 0.25 m/s and -0.1 m/s. The measured results are in good agreement with the calculated ones. When the angle of nozzle is 15° and 20°, the double roll flow is formed. When the angle of nozzle is 45°, the flow field in the mold changes to intermediate flow and the risk of slag entrainment increases significantly. When the nozzle angle is 20°, the surface velocity has a reasonable value, which is conducive to reduce the risk of slag entrainment. With increasing nozzle port angle, the impact point of molten steel jet impinging on the narrow surface moves down. When the nozzle angle is increased from 20° to 45°, the impact point moves down so seriously that makes the inclusions difficult to float up. When the nozzle angle is 15°, the strong double roll flow leads to the increase of the fluctuation near the nozzle. When the nozzle angle is 45°, the fluctuation of the mold level at 1/4 of the width increases, and the turbulent kinetic energy near the nozzle increases obviously. When the nozzle angle is 20°, the fluctuation of liquid level is the smallest, which is beneficial to restrain slag entrainment. Related Articles | Metrics Select High casting speed production practice of hypo-peritectic steel slab Steelmaking    2021, 37 (4): 25-29.   Abstract （82）            Knowledge map    Save In order to solve the problem of period matching of hypo-peritectic steel casting between BOF and CC, improve production efficiency, the stable production of high casting speed of hypoperitectic steel was realized by optimizing mold cooling, oscillation mode and mold powder. After optimization, the cooling water velocity of mould increased from 7.27 m/s to 8.45 m/s, the negative time of mold oscillation mode was controlled from 0.112-0.128 s to 0.151 s， the basicity of mold powder increased from 1.28 to 1.29, the viscosity of 1 300 ℃ decreased from 0.13 Pa·s to 0.12 Pa·s. The maximum casting speed reached 1.6 m/min，the incidence of longitudinal cracks on the surface of slab was less than 0.3 % and the quality of central segregation was stable. Related Articles | Metrics Select Research on characteristics，evolution and control of entrapped mold flux defects in high speed continuous casting Steelmaking    2021, 37 (4): 30-37.   Abstract （191）            Knowledge map    Save High speed continuous casting，continuous casting and rolling process with high efficiency，energy saving and low cost advantages have been rapidly popularized and applied，but encountered development bottleneck due to an increasing frequency of mold flux entrapment in high speed continuous casting and entrapped mold flux defects in rolled products. In this paper, the formation mechanism of mold flux entrapment and its main influence factors were analysed，and characteristics of slag entrapment defect in the slab，hot rolled products and cold rolled products，and their evolution law were briefly described. Finally the control measures of mold flux entrapment in high-speed continuous casting were reviewed. In view of the shortage of existing measures to adapt to the development of high-speed continuous casting，the key development directions are put forward，such as electromagnetic control of the flow field in mold，intelligent control of mold liquid level and development of high-performance mold flux，which can provide reference for promoting the highquality development of high efficiency continuous casting，continuous casting and rolling process. Related Articles | Metrics page Page 1 of 2 Total 73 records First page Prev page Next page Last page