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Steelmaking 2022 Vol.38 Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Latest development of dephosphorization process in converter steelmaking 张润灏, 杨 健, 叶格凡, 孙 晗, 杨文魁 Steelmaking    2022, 38 (1): 1-13.   Abstract （240）            Knowledge map    Save The converter dephosphorization process takes the advantages of capacious furnace，which enables the rapid and efficient dephosphorization with low slag basicity in the early stage of converter steelmaking. The recycling of decarburization slag can also reduce the consumption of lime and other auxiliary materials and the amount of slag emission. Under the conditions of low basicity and low temperature，the low temperature is beneficial to dephosphorization in thermodynamics. But too low temperature will result in the high slag viscosity，which affect the kinetic conditions and make it difficult to pour the slag. The dephosphorization effect is better when the basicity is properly increased. With the increase of FeO content in slag，the dephosphorization ratio first increases and then decreases. The solid and liquid phase coexist in the dephosphorization slag，and the solid solution of Prich phase has good phosphorus enrichment ability. Owing to the complete separation of slag and hot metal after dephosphorization，the duplex process can effectively improve the dephosphorization ratio and is suitable for the production of ultralow phosphorus steel. However，because the process requires two converters，the utilization efficiency of converter is low and the heat loss of intermediate tapping is large. The double slag process only needs one converter，and the cleanliness of molten steel is high，which is an important development direction of converter dephosphorization. Related Articles | Metrics Select Design and application of 120 t converter oxygen lance nozzle Steelmaking    2022, 38 (1): 14-19.   Abstract （204）            Knowledge map    Save Aiming at the characteristics of the 120 t converter and smelting process of a certain plant of Ma’anshan Iron and Steel Co．，Ltd.，the parameters of the original fourhole nozzle of the oxygen lance were optimized．The number of nozzle holes，nozzle angle，operating pressure，throat diameter，outlet diameter and expansion length had all been adjusted appropriately．Mach number of the optimized oxygen lance nozzle had been increased from 1.98% to 2.05%．Combined with the production practice of the plant，it shows that the optimized 5hole nozzle of oxygen lance can increase the oxygen supply intensity of converter，optimize the dynamic reaction conditions in converter，shorten the oxygen blowing time by 128 s，increase the dephosphorization rate by 4.65 %，decrease w(TFe) of final slag from 18.59 % to 15.84 %，and decrease molten hot metal consumption by 22 kg/t，which is not only conducive to improving the scrap steel ratio of converter，but also to improving the metal yield． Related Articles | Metrics Select Cold and thermal simulation test of bottom blowing oxygen and lime powder in converter Steelmaking    2022, 38 (1): 20-25.   Abstract （96）            Knowledge map    Save Related Articles | Metrics Select Experimental study on slag splashing with modified vanadium slag Steelmaking    2022, 38 (1): 26-31.   Abstract （97）            Knowledge map    Save 转炉；钒渣；改质；溅渣护炉 Related Articles | Metrics Select Phosphorus migration behavior during converter slag gasification and dephosphorization Steelmaking    2022, 38 (1): 32-37.   Abstract （70）            Knowledge map    Save Related Articles | Metrics Select Influence of inner diameter of RH impregnating tube on refining and cleanliness of molten steel Steelmaking    2022, 38 (1): 38-41.   Abstract （133）            Knowledge map    Save Related Articles | Metrics Select Study on temperature field of ladle and temperature drop of molten steel in smelting process Steelmaking    2022, 38 (1): 42-48.   Abstract （146）            Knowledge map    Save Related Articles | Metrics Select Laboratory study on precipitation of MnS in solid low sulfur steel Steelmaking    2022, 38 (1): 49-55.   Abstract （114）            Knowledge map    Save Related Articles | Metrics Select Effect of different pulling speed on the solidification process and microstructure of thin slab Steelmaking    2022, 38 (1): 56-62.   Abstract （126）            Knowledge map    Save Related Articles | Metrics Select The practice of tellurium to control the form of sulfide in nonquenched and tempered steel Steelmaking    2022, 38 (1): 63-67.   Abstract （119）            Knowledge map    Save Related Articles | Metrics Select Study on metallurgical technology of high temperature electrothermal alloy of FeCrAl Steelmaking    2022, 38 (1): 68-72.   Abstract （96）            Knowledge map    Save Related Articles | Metrics Select Evaluation of Tebased freecutting steel and its machinability Steelmaking    2022, 38 (1): 73-79.   Abstract （74）            Knowledge map    Save Related Articles | Metrics Select Study on IAF induced by inclusions in magnesiumtreated shipbuilding steel Steelmaking    2022, 38 (1): 80-86.   Abstract （50）            Knowledge map    Save Related Articles | Metrics Select Review on the control of the acicular ferrite in high strength low alloy steels Steelmaking    2022, 38 (2): 1-10.   Abstract （202）            Knowledge map    Save The formation of volumes of acicular ferrite in high strength low alloy steels is a principal mean to meet high strength and toughness. Several decisive factors affecting the volume fraction of acicular ferrite were reflected in different literatures, and the nucleation mechanism of acicular ferrite and inclusions characteristics conducive to nucleation were summarized by some review, but there was no systematic summary of the effect of variation on apiece factor. In this study, the influence of austenite grain size, cooling rate, inclusion composition, and inclusion size on the volume fraction of acicular ferrite has been summarized. It is concluded that austenite grain size of 100-200 μm, cooling rate of 5-10 ℃/s, inclusion size of 1-2 μm and composition of (Ti、Mg、Zr)Ox are beneficial to promote acicular ferrite nucleation.  Related Articles | Metrics Select Research progress on desulfurization reaction dynamics of hot metal by KR mechanical stirring Steelmaking    2022, 38 (2): 11-19.   Abstract （141）            Knowledge map    Save KR hot metal desulphurization (also known as mechanical stirring method) has the advantages of high desulfurization efficiency,stable desulfurization effect and low desulfurization cost due to its better reaction conditions. It is widely used in major domestic and foreign steel companies and has gradually become the preferred process for hot metal desulfurization pretreatment.  The research results in recent years on improving the dynamic conditions of the KR mechanically stirred hot metal desulfurization were summarized. By understanding the development of the desulfurization reaction at home and abroad，it provides references for the improvement or optimization of KR dynamic conditions. Related Articles | Metrics Select Application of nickel-containing pig iron in converter smelting of nickel-containing steel Steelmaking    2022, 38 (2): 20-24.   Abstract （153）            Knowledge map    Save Combined with the practice of a domestic steel plant, the thermodynamic analysis and kinetic research for the application of nickel-containing pig iron in the converter smelting of nickel-containing steels were carried out. Thermodynamic calculations show that, whether in standard state or actual condition of converter smelting, the nickel element dissolved into the molten iron or molten steel through the alloying of the nickel-containing pig iron cannot be oxidized to nickel oxide. The melting rate test of nickel-containing iron block in converter smelting of X80-1 steel showed that the melting rate of nickel-containing iron block with 25 mm thickness was 30 s faster than that of scrap steel. The composition test results of converter semi-steel showed that the nickel-containing iron block could be completely melted after being added into the converter in 5 min. At the same time, through the scanning electron microscopy and X-ray power diffraction of the final slag of the converter, no nickel oxide was found, and the yield rate of nickel in nickel-containing iron block was close to 100 %. Related Articles | Metrics Select Study on ion migration behavior of lime in dissolution of gasification dephosphorization slag Steelmaking    2022, 38 (2): 25-31.   Abstract （90）            Knowledge map    Save For converter gasification dephosphorization slag system, the kinetics of static lime dissolution in slag was studied. The research results show that in the temperature range of 1 200～1 500 ℃, as the temperature increases, the melting rate of lime increases, the activation energy of lime melting is Ea=203.1 kJ/mol, the linear equation fitting the relationship between the rate constant and the temperature is ln vr=-24.43/T-14.62. The limiting link of lime melting is diffusion control. Analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD) the molten slag layer-the boundary layer-the lime layer, the research results show that the migration rate of the slag component Fe2+ is faster than the migration rate of SiO44-, from the lime surface to the inside, CaO-SiO2 composite phase is mainly formed on the lime surface, and more Fe elements will be present inside, forming the main CaO-FeO composite phase. Related Articles | Metrics Select Study on improving calcium yield of pure calcium wire Steelmaking    2022, 38 (2): 32-35.   Abstract （167）            Knowledge map    Save The factors affecting the calcium yield of pure calcium wire were studied through theoretical analysis and production practice. The results show that,1) Reducing the diameter of feeding tube can reduce the deflection of and the pilling up of calcium wire；2) The effective absorption range of calcium is from 0.3 m above the bottom to 1.22 m below the liquid level; 3) The feeding speed of calcium wire is affected by the algam thickness of  calcium wire, and the  calcium wire with different algam thickness has an optimal feeding speed；4) When feeding wire at the downward flow position of argon bubble flow, the calcium yield is better than that at the upward flow position of argon circulation flow；5) The calcium yield of wire packing with seamless is better than that with slit algam tube；6) The composition of molten steel affects the vapor partial pressure of calcium, the effective absorption range of calcium is changed, and then the residence time of calcium in molten steel is different. Related Articles | Metrics Select Study on application of composite powder cored wire Steelmaking    2022, 38 (2): 36-42.   Abstract （79）            Knowledge map    Save Fe-Si+CaO composite powder cored wire was added into molten steel, and its effect on the removing inclusions was studied. The results show that the composite powder cored wire can be added into molten steel，in which the composite powder can diffuse into molten steel and form Si-Ca-Al composite inclusions with the inclusions in molten steel. The appearance of composite inclusions is spherical，which is easy to accumulate and float up. The industrial trial results show that，the composite powder cored wire can remove inclusions and purify molten steel without affecting the control of steel composition. The T.O content，area content and number density of inclusions are decreased significantly，and the sizes of inclusions remaining in the slab are mostly less than 4 μm，and no size larger than 10 μm inclusions. Related Articles | Metrics Select Numerical simulation of structural optimization and inclusion removal in single strand tundish Steelmaking    2022, 38 (2): 43-48.   Abstract （125）            Knowledge map    Save To solve the problem of poor flow state in the process of continuous casting and high percentage of the inclusions in molten steel, some improvement schemes regarding the flow control device of single strand tundish were proposed. The flow field and average residence time distribution of molten steel in the tundish under different schemes were comparatively investigated by numerical simulation and water model experiment. The optimal combination of flow control devices was proposed, the distance between the weir and the long nozzle is 1 090 mm, the height of the weir is 180 mm, the distance between of the weir and the dam is 260 mm, the height of the higher dam is 340 mm. Compared with the prototype tundish, the average residence time and plug zone are increased and the dead zone ratio is reduced by 7.14 %.The average removal rate of inclusions reaches 68.7 %, which is 6.6 % higher than the prototype tundish. Related Articles | Metrics Select Control and improvement for surface quality of peritectic steel billet with high casting speed Steelmaking    2022, 38 (2): 49-53.   Abstract （127）            Knowledge map    Save For the disadvantages of traditional mold flux of peritectic steel, this paper proposed a novel type of mold flux, which combined both heat transfer and lubrication effects, providing a new solution for the stable highefficiency production of peritectic steel billet. Through the proper decrease of basicity and viscosity of previous mold flux for peritectic steel，introduction of LiO2 and oxides of transition metallic elements（Fe2O3，MnO），as well as the content reduction of fluorine, the applicability and stability of the mold flux for the casting of peritectic steel billet at high casting speed were improved. In view of associrelation and compatibility of series flux properties, as well as service conditions, the qualified ratio of defect-inspection for the peritectic steel billet was highly improved from less than 35 % to more than 93 %，and a continuous high-efficiency and high-quality production way of peritectic steel billet was achieved with the appropriate employment of the novel mold flux for peritectic steel. Related Articles | Metrics Select Stimulation analysis of volume expansion and application practice for 300 t ladle Steelmaking    2022, 38 (2): 54-59.   Abstract （124）            Knowledge map    Save In view of steel production capacity improvement and the transformation of big scrap steel ratio production mode, the requirement for ladle volume expansion was put forward. Through modeling and numerical calculation after ladle volume expansion，the temperature field and stress field were analyzed. After the expansion ladle reached the steady-state cycle, the ladle wall surface temperature reached the maximum value of 280 ℃,and the slag line position reached the maximum value of 310 ℃, which was in the safe range. The thickness of the working layer of ladle wall was reduced by 30 mm, the effective capacity of the ladle was increased from 277 t to 286 t, and the monthly production capacity was increased by 18 000 t. While promoting the improvement of steelmaking capacity, the power cost, refractory cost and labor cost were reduced, and the annual economic benefit was about 14 million yuan.  Related Articles | Metrics Select Influence of nozzle aggregated inclusions on fatigue cracks and their control in wheel Steelmaking    2022, 38 (2): 60-66.   Abstract （55）            Knowledge map    Save The characteristics of rim cracks and inclusions in the wheel were analyzed,it was shown that the type of fatigue cracks was caused by the aggregated large-size inclusions in the steel.These inclusions originated from the aggregated attachments on the inner wall of the nozzle. In the casting process, the endogenous inclusions in the molten steel aggregated and adhered on the inner wall of the nozzle, the inclusions would fall off randomly and remained in the billets during solidification.These large inclusions were distributed at the position of 20-40 mm from the surface of the continuous casting billet, which were distributed in the wheel rim area after wheel rolling, located at 10-20 mm below the tread. The sizes of inclusions generally exceeded 500 μm, and the main composition was calcium aluminate. For the process optimization of calcium treatment and electromagnetic stirring and shielding casting in the overall process of continuous casting, the aggregation and attachment of inclusions on the inner wall of nozzle have been effectively controlled. The stability of continuous casting and the wheel quality have been significantly improved. The total number of large-sized inclusions was reduced by more than 76 % and the number of inclusions larger than 1 mm was greatly reduced to 8 % from 35 %. Related Articles | Metrics Select Analysis of influencing factors of surface linear defects of non-oriented electrical steel Steelmaking    2022, 38 (2): 67-74.   Abstract （65）            Knowledge map    Save Combining scanning electron microscopy and large sample electrolysis, the composition and source of inclusions in the surface linear defects of W800 grade non-oriented electrical steel in the CSP process were studied. SPSS software was used to regress and analyze the main factors which affected the surface linear defects in the steelmaking process. Research shows that the content of large inclusions in the steady state casting process is 5.39 mg/10 kg. The large inclusions which cause linear defects on the surface of non-oriented electrical steel are mainly deoxidized products, magnesia-aluminum spinel and ladle top slag, and the main types are Al2O3, MgO-Al2O3, CaO-Al2O3-MgO and CaO-Al2O3-SiO2. The cleanliness of steel in the unsteady casting process reduces significantly, and the proportion of linear defects on the surface of the hot-rolled sheet increases. The main factors affecting the surface linear defects are w(CaO)/w(Al2O3) at the top slag of RH exit, oxygen level at the end of RH deoxidation and minimum tonnage of tundish in continuous casting process. Related Articles | Metrics Select Influence of excess air coefficient on operation of converter waste heat boiler Steelmaking    2022, 38 (2): 75-82.   Abstract （123）            Knowledge map    Save The safe operation of the converter waste heat boiler is affected by factors such as blowing time, excess air coefficient, flue gas velocity, etc. Among them, the excess air coefficient is most closely related to practical production. Based on the thermal calculation process of the converter waste heat boiler, a thermal calculation program was compiled, and change rules of theoretical combustion temperature, heat transfer and exhaust gas temperature were obtained based on the program when the excess air coefficient changed. To the 180 t converter waste heat boiler, under the conditions that the primary furnace gas temperature is 1 600 ℃ and gas volume composition is 90 % CO and 10 % CO2, the result shows the theoretical combustion temperature increases by 286.1 ℃, the proportion of CO in flue gas decreases from 72.468 % to 41.052 %, the heat transfer increases significantly, and the exhaust gas temperature increases by 139.12 ℃ as the excess air coefficient increases from 0.08 to 0.3. Related Articles | Metrics Select Study on the mechanical properties of carbonation of steel slag bricks Steelmaking    2022, 38 (2): 83-88.   Abstract （136）            Knowledge map    Save In order to find a new method of utilizing steel slag, the steel slag aggregate from Jinan Iron and Steel Plant was placed in an airtight container and carbonated with 100 % CO2. Experimental results showed that steel slag could absorb CO2 under a certain pressure, and the strength of steel slag specimen after carbonation was greatly improved compared with that without carbonation. When the water-cement ratio of steel slag powder was 14.5 % by gravimetric method, the weight gain rate of carbonation of steel slag brick was 15.05 %, and the corresponding compressive strength and flexure strength were 36.88 MPa and 9.69 MPa respectively. According to XRD and FE-SEM microscopic test methods, the reason for the improvement of mechanical properties of specimens was that the Ca2+ in steel slag, the water added with CO2 carbonated to generate CaCO3, resulting in a denser microstructure and reducing pore diameter. Related Articles | Metrics Select Water modeling of the influence of bottom inclination on the mixing phenomena in KR process Steelmaking    2022, 38 (3): 1-5.   Abstract （137）            Knowledge map    Save Related Articles | Metrics Select Research and application of high efficiency and long life combined blowing technology for 300 t converter in Masteel Steelmaking    2022, 38 (3): 6-11.   Abstract （224）            Knowledge map    Save Related Articles | Metrics Select Prediction of slag liquidus temperature based on machine learning algorithm Steelmaking    2022, 38 (3): 12-19.   Abstract （126）            Knowledge map    Save Related Articles | Metrics Select Effect of basicity on physicochemical properties and phosphorus migration of refined slag Steelmaking    2022, 38 (3): 20-25.   Abstract （192）            Knowledge map    Save Related Articles | Metrics Select Molten steel flow and inclusions behavior during RH vacuum treatment based on ladle bottom argon blowing Steelmaking    2022, 38 (3): 26-31.   Abstract （196）            Knowledge map    Save Related Articles | Metrics Select Study on LF refining desulfurization process for SPHC steel Steelmaking    2022, 38 (3): 31-36.   Abstract （201）            Knowledge map    Save Related Articles | Metrics Select Research on metallurgical effect of doublechannel electromagnetic induction heating tundish Steelmaking    2022, 38 (3): 37-42.   Abstract （95）            Knowledge map    Save Related Articles | Metrics Select Analysis and control of reticular crack on the surface of continuous casting round billet Steelmaking    2022, 38 (3): 43-47.   Abstract （101）            Knowledge map    Save Related Articles | Metrics Select Evolution of nonmetallic inclusions in rareearth treated nonoriented electrical steel Steelmaking    2022, 38 (3): 48-57.   Abstract （52）            Knowledge map    Save Related Articles | Metrics Select Evolution of the nonmetallic inclusions of bearing steel produced by 90 t EAF→LF→VD→CCM process Steelmaking    2022, 38 (3): 58-61.   Abstract （180）            Knowledge map    Save Related Articles | Metrics Select Variation law of typical inclusions in bainitic steel production process Steelmaking    2022, 38 (3): 62-68.   Abstract （128）            Knowledge map    Save Related Articles | Metrics Select Cause analysis and improvement measures of unqualified ultrasonic flaw detection for largesize storage tank steel 12MnNiVR#br# Steelmaking    2022, 38 (3): 69-72.   Abstract （137）            Knowledge map    Save Related Articles | Metrics Select Study on fine characterization of microstructure difference of wire rod for ultra-fine steel saw wire#br# Steelmaking    2022, 38 (3): 73-84.   Abstract （110）            Knowledge map    Save Related Articles | Metrics Select Numerical simulation and application of desulfurization lance with external spiral guiding groove Steelmaking    2022, 38 (4): 1-6.   Abstract （83）      PDF（pc） （1492KB）（41）       Knowledge map    Save Aiming at the poor kinetic conditions of hot metal desulfurization with granular magnesium injection by a lance with single straight nozzle and the difficulties in the implementation of mechanical lance rotation, a lance with external spiral guiding groove was proposed, and the injection process was numerically simulated. It is found that the lance with spiral guiding groove can effectively improve the stirring of hot metal and reduce splashing compared with the conventional one. The industrial test and application of hot metal desulfurization with granular magnesium injection in a 250 t hot metal ladle in a steel plant show that, the hot metal splashing and magnesium vapor combustion on the slag surface are significantly reduced. The unit consumption of desulfurizer is reduced by 6.0 % on average and the average service life of injection lance reaches 180 heats, which show its excellent application effect.  Related Articles | Metrics page Page 1 of 2 Total 77 records First page Prev page Next page Last page