Volumn Content

Steelmaking 2012 Vol.28 Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Trial production of free cutting gear steel by converter process under semisteel steelmaking condition Steelmaking    2012, 28 (1): 1-4,10.   Abstract （521）            Knowledge map    Save In view of the composition characteristics and quality requirement of free cutting gear steel 20CrMnTiH（FQ）and in combination with the production conditions of equipment and process in Panzhihua Steel, technologies of free cutting gear steel producing have been studied. With these technologies such as sulfur content increasing in semisteel, endpoint control of converter, proper deoxidation process, reasonable aluminium control, secondary refining process, modification of inclusions type A with segmented calcium treatment, sulfur content increasing after RH refining process, as well as optimization of parameters in continuous casting process, 20CrMnTiH（FQ）can be produced steadily with semisteel making conditions in the process of Convert Steelmaking→LF→RH→Continuous Casting. Results of industrial production indicate that the compositions of 20CrMnTiH（FQ）steel can be confined in a narrow range, and sulfur in steel controlled steadily as well. Moreover good surface and internal quality of continuous casting billet can be produced and w（T.O）is governed in the range of （11～18）×10-6with the average value of 14.7×10-6. Nonmetal inclusion in steel and performance index of rolled bars can meet the requirements of consumers. Related Articles | Metrics Select Analysis of CaS inclusions in calcium treated drilling steel Steelmaking    2012, 28 (1): 5-7,19.   Abstract （580）            Knowledge map    Save The character of inclusions in calcium treated 37CrMnMo was analyzed. Fine spheroidzed CaO-Al2O3-CaS complex inclusion was formed after proper calcium treating. However some discontinuous granular CaS inclusions were found in the steel. The effect of Al, Ca, O, S on the forming of CaS was discussed through data statistics and thermodynamic. Finally, effective measurement was brought forward. Related Articles | Metrics Cited: Baidu(3) Select Application of spectral inclusion analysis technology in IF steel Steelmaking    2012, 28 (1): 8-10.   Abstract （509）            Knowledge map    Save The technology of spectral inclusion analysis by a PDA spectroscope is introduced. The Al2O3 inclusion contents in the qualified heats as well as inclusion caused rejected heats of liquid steel used for cold rolled IF steel sheets purposes are analyzed at the RH end point in the process of refining and at the intermediate phase of tundish casting by means of this technology. Preliminary inclusion control tech index for IF steel sheet in the process of refining are put forward as follows: RH endpoint inclusion quality fraction be controlled within the limit of less than 0.004 5 %and inclusion quality fraction in the tundish, in less than 0.003 0 %. Since application of the technology in the actual production practice of IF steel sheet in 2009 in combination of the other processes the rejected rate of the cold rolled IF steel sheets arising from inclusions have been dramatically reduced. Related Articles | Metrics Select Effect of electromagnetic stirring in secondary cooling zone on quality of continuous casting slab of nonoriented silicon steel Steelmaking    2012, 28 (1): 11-14,2.   Abstract （615）            Knowledge map    Save The effect of electromagnetic stirring parameters in secondary cooling zone on equiaxial crystal rate, center segregation and white band of continuous casting slab of XG800WR nonoriented silicon steel was investigated. The results show that the equiaxial crystal rate of slab grows from 19.6 % to 26.5 % when stirring current varies from 0 A to 400 A. The equiaxial crystal rate of slab grows from 21.7 % to 26.1 % when stirring frequency increases from 0 Hz to 8 Hz. With stirring current increasing, the segregation degree of S, Si, Mn in slab center is firstly decreased and then increased. When stirring intensity is excessive the white band appears and in the area of the white band the negative segregation of Si, Mn and S occurs and the negative segregation index of S is the largest. All of the phenomena will consequently lead to an increase of positive segregation of S, Si and Mn in the center of slab. In a comprehensive consideration of increase of the equiaxial crystal rate, reduction of central segregation and avoidance of white band occurrence the 350 A/6 Hz is selected as the optimal electromagnetic stirring parameters. Related Articles | Metrics Select Monitoring & analysis on mold cooling water temperature difference for bloom continuous casting Steelmaking    2012, 28 (1): 15-19.   Abstract （568）            Knowledge map    Save According to large quantities of measured data, the present paper discussed the relationship between the temperature difference of cooling water in the mold and the process parameters such as casting speed, superheat and mold water flow rate, and the multivariate statistical method was used to expound its quantitative law. Secondly, the functions of monitoring water temperature difference were illustrated mainly to guide the development and optimization in the cooling process. Finally, the mean filtering method was applied to the data acquisition so as to ensure the calculation accuracy and stability of dynamic thermal tracking model for casting bloom and practice demonstrates the necessity and effectiveness of the method. Related Articles | Metrics Select Origin of corner crack of slab for automobile beam steel M510L and optimization of secondary cooling process Steelmaking    2012, 28 (1): 20-24.   Abstract （607）            Knowledge map    Save On the basis of analysis on the high temperature mechanics properties of the automobile beam steel M510L the secondary cooling process for the No.2 Continuous Casting Machine of Ma’anshan Steel Co., Ltd. has been optimized and therefore the high temperature ductility has been improved. In the meanwhile every possible means has to be taken to keep away from the fragile sensitive zone. The corner quality of the slab has been improved and the rate of corner trimming rate of steel M510L lowered to 15 % from original 95 % due to optimization of the secondary cooling water supply as well as insurance of the accuracy of the arc for the segments and the accuracy of the roll gap control. Related Articles | Metrics Select Research on mechanism of longitudinal surface crack formation of thin slab and mould taper Steelmaking    2012, 28 (1): 25-28.   Abstract （574）            Knowledge map    Save Mechanism of longitudinal surface crack formation of thin slab is discussed from the view of mechanics. The effect of control process of mould taper on longitudinal surface crack of thin slab is analyzed. Controlling measures on longitudinal surface crack are discussed in detail. The results show that local tensile stress concentration is one of main reasons to promote formation of longitudinal surface crack. Controlling measures on longitudinal surface crack include two ways. One is improving the growing uniformity of solidified shell. It can be carried out by optimizing continuous casting process. The other is promoting optimization of contact situation between mould and solidified shell and it can be assured by optimizing inner structure of mould and adjusting taper. Related Articles | Metrics Cited: Baidu(1) Select Reasons for formation of longitudinal crack of CSP slab and preventing measures Steelmaking    2012, 28 (1): 29-32,3.   Abstract （530）            Knowledge map    Save Longitudinal cracks on surface of thin slab are common defects in continuous casting of CSP.According to the formation mechanism of longitudinal cracks in continuous casting process of CSP slab，combining with site experience of WISCO production, this article analyses the reasons of formation and expansion of longitudinal cracks from composition of liquid steel，taper of mould，behavior of casting powder，second cooling condition，equipment accuracy and so on.The article puts forward the measures for effective control the longitudinal cracks of CSP slab.After tackling key measures，the modify ratio reduced from 3.22 % in December 2009 to 0.43 % in December 2010，and longitudinal cracks are effectively controlled. Related Articles | Metrics Select Experimental study on environmentfriendly dephosphorization agent for  high phosphorus hot metal pretreatment Steelmaking    2012, 28 (1): 33-36.   Abstract （503）            Knowledge map    Save In order to develop high efficient and environmentfriendly dephosphorization agents, in this paper, the FactsageTM was used to plot ternary phase diagram about Fe3O4-CaO-B2O3 and Fe3O4-CaO-K2O. The mass fraction of B2O3 system andK2O system dephosphorization agents were determined by the ternary phase diagram. Then dephosphorization experiments were conducted in the laboratory. The experimental results of high phosphorus hot meal predephosphorization using B2O3 as a flux were compared with that using CaF2 as a flux. The results show that, as a flux, B2O3 can replace completely CaF2 to predephosphorize the high phosphorus hot metal. This dephosphorization agent can remove phosphorus to below 0.1 %. In this case the ratio of w( B2O3 ) and w(CaO) is 0.16. When this dephosphorization agent is used to dephosphorize, there is good state of slag melting. At the same time no foaming slag appears. And its dephosphorization rate is the highest in all of dephosphorization agents. But K2O system dephosphorization agent has unsatisfactory dephosphorization efficiency. Related Articles | Metrics Select Water modeling study on auxiliary deslagging process by air blowing in hot metal tank Steelmaking    2012, 28 (1): 37-39,5.   Abstract （509）            Knowledge map    Save By way of water modeling the deslagging process with air blowing in the hot metal pot is investigated. In the meanwhile the effects of factors such as the type of the air brick, fixing position and rate of blowing air flow on the results of deslagging by auxiliary air blowing are systematically studied. Results show that the double blowing process is better than the single one and the twin bubble brick is superior over the traditional single bubble brick and moreover the lower the bubbling element is fixed and the larger the spread area of the blown liquid level is, the better the deslagging effects will be. Since the successful application of the experimental results in the onsite production the deslaging time is reduced to about 6 minutes from the original 12 minutes and the hot metal deslagging rate is drastically improved and sulfur pickup rate in the converter is effectively controlled within 0.005 %. Related Articles | Metrics Cited: Baidu(1) Select Analysis and optimization of V and Ti containing hot metal desulfurization process Steelmaking    2012, 28 (1): 40-43.   Abstract （537）            Knowledge map    Save In combination with the basic situation of vanadium and titanium containing hot metal desulphurization in a specific plant, the characteristics and the main problem of vanadium and titanium containing hot metal desulphurization process were analyzed. Through experiment research and field tracing, the physical and chemical properties of hot metal containing vanadium and titanium, hot metal temperature, the desulphurizing ability of desulfurizer, process operation and other factors affecting the desulphurization performance have been studied. And combined with field desulphurization production, the optimization of desulphurization process for the hot metal containing vanadium and titanium was carried out and good effect obtained accordingly. Related Articles | Metrics Cited: Baidu(1) Select Effect of oxygen content on cutting performance in sulfur free cutting steel Steelmaking    2012, 28 (1): 44-47,6.   Abstract （471）            Knowledge map    Save The present paper studies the effect of oxygen content on sulfide inclusions and cutting performance of the sulfur free cutting steel. The results show that cutting performance of the steel tends to be better and better with increase of oxygen content within a certain range because massive spindle (Mn, Fe) (S, O) complex inclusions can be formed in steel when oxygen content is high. In the cutting process this kind of sulfides can cut off the continuity of matrix and form a protective film on the cutter surface to reduce tool wear. The results of cutting experiment show that the cutting performance is better than steel 45 when oxygen content is 0.014 % and ideal cutting performance can be obtained. Related Articles | Metrics Cited: Baidu(1) Select Influence of calcium treatment on total oxygen content in non-oriented silicon steel Steelmaking    2012, 28 (1): 48-51.   Abstract （490）            Knowledge map    Save The SiCa cladded wire is fed into the hot metal after RH vacuum treatment. The effect of Ca treatment on the total oxygen content of the nonoriented silicon steel is investigated by comparison of variation of T.O and N as well as change of sizes and quantity of inclusions before and after Ca feeding. Thermal dynamical calculation shows that in the nonoriented silicon steel the total oxygen in steel can basically represent the total quantity of the oxide inclusions in the steel due to higher Al and low free oxygen content in the steel. The total oxygen content in steel can be drastically reduced through Ca treatment mainly because the inclusions modified by Ca treatment will grow larger and their concentration is accordingly reduced. Thereby those relatively larger inclusions will more easily float up. Related Articles | Metrics Cited: Baidu(2) Select Study and application of flow field of asymmetrical 5 strand tundish Steelmaking    2012, 28 (1): 52-56.   Abstract （507）            Knowledge map    Save By water modeling the optimal plan for baffle of the asymmetrical five strand tundish has been determined and law of distribution of inner flow field and temperature field of the tundish studied by application of numerical simulation. Results show that since optimization the flow field and temperature field of the tundish tend to be consistent and uniform and the internal structure inside each strand is of high uniformity and the internal quality of the bloom is excellent and they can basically meet the product quality requirements and production demand. Related Articles | Metrics Select Optimization of secondary cooling scheme for 40Cr alloy structural steel in billet continuous casting Steelmaking    2012, 28 (1): 57-61.   Abstract （548）            Knowledge map    Save The solidification and heat transfer model for billet continuous casting is established and the model accuracy validated by the infrared temperature measurement method. By model calculation the problems currently existing in the secondary cooling schedule for the 40 Cr alloy steel is analyzed and at the same time the problems of over strong cooling intensity at the food roll segment, higher temperature recovery existing in the No.1 zone of the secondary cooling segment, excessive secondary cooling water volume and relatively lower surface temperature of the billet at the straightening zone are found out. A reasonable set of K value combination ( water volume adjustment parameters) is fed into the model computer after optimization and then a more reasonable K value combination namely K0=0.3，K1=1.0，K2=0.9，K3=0.7 is obtained. At the same time the secondary cooling water rate is lowered, the straightening temperature of the billet raised, the brittle temperature zone avoided and thus the rate of crack occurrence of the billet reduced. It can be used as guidance for the process optimization of the billet continuous casting. Related Articles | Metrics Cited: Baidu(1) Select Influence of copper plate thickness on thermomechanical behavior of slab mold Steelmaking    2012, 28 (1): 62-65.   Abstract （559）            Knowledge map    Save In connection with the practical conditions of one caster in a specific plant a threedimensional thermal elasticplastic finite element model is established and distributions of temperature, deformation rate and equivalent stressstrain for copper plates with different thickness are obtained. All those parameters are used to guide the design of mold in the Steelmaking Co., Ltd. of Hebei Puyang Iron & Steel Corporation. Results show that the thicker the copper plate is, the higher the temperature will be at the hot surface, and the less the equivalent stress is, the larger the deformation rate will become. Every 5 mm increase in the thickness of the copper plate will inevitably lead to about 30 ℃ temperature increase in the highest hot surface and about 7.5 MPa reduction of the maximum equivalent stress at the hot surface and about 0.05 mm increase of the maximum deformation rate at the hot surface. Thinner copper plate is more helpful for reduction of the hot deformation of the copper plate in the process of casting. Related Articles | Metrics Select RH process design under low rail surface elevation condition Steelmaking    2012, 28 (1): 66-69.   Abstract （654）            Knowledge map    Save The present paper introduces the RH process design under low rail surface elevation condition and describes in detail the design of lowering the top elevation of top oxygen blowing gun and the elevation of ferroalloy feeding system. This process design has been successfully applied to a number of construction project such as 100 t RH of Lianyuan Iron & Steel、150 t RH of Xiangtan Iron & Steel、120 t RH of Jiuquan Iron & Steel and 120 t RH of Liuzhou Iron & Steel. It is of great significance for improvement in the design and process level of the similar equipments in China. Related Articles | Metrics Cited: Baidu(1) Select Analysis on failure of mold copper plate of continuous caster and counter measures Steelmaking    2012, 28 (1): 70-73,7.   Abstract （496）            Knowledge map    Save In order to increase the service life of casting molds，some improving measures are put forward. The failure reasons of copper plate and its surface coatings are analyzed. In addition，the design of the casting mold，the selection of materials and surface hardening technology are studied. Furthermore，by means of comparison of Ag-Cu and Cr-Zr-Cu metallographic structure photos，Cr enriched metal compounds segregated from the interface of the copper crystal cells is primary cause to the thermal cracks of the Cr-Zr-Cu mold plate. The internal stress distributions of alloy electroplated layers，thermal spray coatings and nanoceramic composite coatings are researched，and production technology of the copper plate coating was optimized. A new coating layer with low stress is developed independently without any organic additives，which used in some steelmaking works and scratch resistance and thermal crack resistance of casting mold are very satisfactory in the actual application of the technology. Related Articles | Metrics Cited: Baidu(5) Select Status of research on mold flux for high aluminum steel Steelmaking    2012, 28 (1): 74-78.   Abstract （623）            Knowledge map    Save In light of the characteristics that the mold flux Al2O3 content is enormously increase in the process of continuously casting the high Al steel the present paper introduces the origin of Al2O3 in the mold flux and its influence on the properties as well as absorption of Al2O3 by the mold flux. By way of summarizing the status quo of research on the high Al containing mold flux at home and abroad in the recent years it's found out that at present time most of the mold flux are mainly composed of low Al2O3 and high SiO2constituents and a large quantity of slag rim are formed in process of usage, thus resulting in occurrence of deeper surface depression of the slab. On the contrary high Al2O3 and low SiO2 constituents can help keep chemical compositions and properties of the mold flux intact in continuously casting the high Al steel and therefore they can be used in the research and development of the mold flux for high Al steel. Related Articles | Metrics Select Process flow and its application practice at Shougang Jingtang new generation steelmaking plant Steelmaking    2012, 28 (2): 1-6.   Abstract （615）            Knowledge map    Save The technology for clean steel production in a modern steelmaking plant is analyzed and the technological philosophy of the clean steel production with efficiency, manufacturing cost and product performance as its core is also put forward. By way of reviewing and integrating the manufacturing functions of the high efficiency, low cost and high quality steel produced by the steelmaking plant of new generation and by optimizatiing allocation of the operating procedures such as hot metal pretreatment, converter smelting, secondary refining and continuous casting with the help of the dynamic and precise design system in connection with the design and research of the steelmakingcontinuous casting process at Shougang Jingtang Iron & Steel Plant a clean steel production platform with dynamic and orderly production system as its base is built up. Related Articles | Metrics Cited: Baidu(9) Select Application of high efficient desulfurization process in KR complex desulfurater Steelmaking    2012, 28 (2): 7-9.   Abstract （498）            Knowledge map    Save On the basis of the characteristics of the 200 KR desulfurization equipments and its operating processes in the No.4 Branch of General Steelmaking Plant of Wuhan Iron and Steel Corporation a high efficient desulphurization method is developed. Results of application show that by application of the newly developed process not only product quality and productivity as well as desulphurization effects can be ensured, but the ratio of the low sulphur steel products w(S)≤60×10-6 is also raised by 31 % and in the meanwhile consumption of conventional CaObased desulphurizer is lowered by 24.0 % and consumption of passivation CaO based desulphurizer is reduced by 10.7 %. Thus both good technological and economical results have been achieved. Related Articles | Metrics Cited: Baidu(3) Select Development and application of prediction model of end pointphosphorus content in 260 t converter Steelmaking    2012, 28 (2): 10-13,2.   Abstract （462）            Knowledge map    Save In light of process characteristics of the converter refining and the production data of the Steelmaking plant of hanbao Iron & Steel Co., Ltd. of Han Steel Group a PCA-GA-BP neural network based end point phosphor content prediction model for the converter is developed. Principal component analysic (PCA) is used to reduce dimension of the factors affecting the end point phosphor content and at the same time the genetic algorithm(GA) is applied for optimization of the initial weights of BP neural network. Then, a software of prediction model of end point phosphor content is developed by Java. And the software is applied in the converter mill. The results show that the hit rate to phosphor content predicted by model reaches 96.67%, 93.33 %and 86.67 %with control precision among ±0.007 %，±0.005 %and ±0.004 % for heats of the experiment respectively. Related Articles | Metrics Select Technology of nitrogen regulation in steel during LF process and its practice Steelmaking    2012, 28 (2): 14-16,2.   Abstract （461）            Knowledge map    Save The present paper introduces the nitrogen content in Al killed steel in the process of refining by route of “BOF→LF→CC” in the Vanadium Recovery and Steelmaking Plant of Pangang Group Panzhihua Steel & Vanadium Co., and analyzes the main factors affecting nitrogen pickup in steel in LF refining involving a few greater influential factors such as compositions of steel, effects of submerged arc in heating, argon blow and cladded wire rod feeding and puts forward certain counter measures. By adoption of such a few measures as manipulating the submerged arc more carefully, regulating the heating level more appropriately and stabilizing argon blow nitrogen pickup in LF refining is already well controlled and the quality fraction of nitrogen pickup in LF refining is steadily controlled within the limit of 2×10-6. Related Articles | Metrics Cited: Baidu(7) Select Deoxidation and inclusion control of ER70S-6 welding wire steel during LF refining Steelmaking    2012, 28 (2): 17-19.   Abstract （427）            Knowledge map    Save Deoxidation and inclusion control for ER70S6 welding wire steel are investigated through thermodynamic calculation and plantscale experiments. The morphology, chemical compositions and size of inclusions in liquid steel are analyzed by SEM/EDS. Thermodynamic calculation results show that the quality fraction of dissolved oxygen in liquid steel is more than 40×10-6after deoxidation using SiMn alloy and the quality fraction of dissolved oxygen can be reduced to less than 10×10-6through control of slag chemical composition. Experimental results show that the number of inclusions with the diameters of more than 20 μm decreases from 22.3 % to 6.1 %; the inclusion type after LF refining is globular CaO-Al2O3-SiO2-MnO-Ti2O3 inclusions and the melting points for 89.8 %of these inclusions are below 1 600 ℃. The quality fraction of total oxygen in final products is 24.5×10-6averagely, which meets the requirement of downstream customers. Related Articles | Metrics Cited: Baidu(3) Select Effect of the position of soft reduction on the centralsegregation of 400 mm ultra-thick slabs Steelmaking    2012, 28 (2): 20-23.   Abstract （424）            Knowledge map    Save The present paper introduces the production status of 400 mm ultra-thick slabs and analyzes the influence of the position of soft reduction on the central segregation of ultrathick slabs. Results show that expansion of the space between the dual phase zone and the solid phase is more beneficial to improve the central segregation of the ultra-thick slab. Results of C and S chemical analysis show that the central segregation of 400 mm ultra-thick slab is similar to that of 250 mm medium gauge slab and the distribution of chemical compositions of the liquid steel in the width direction is uneven and the liquid pool is in a W shape. Related Articles | Metrics Select Practice in reduction of corner crack in CC slab Steelmaking    2012, 28 (2): 24-28.   Abstract （454）            Knowledge map    Save The corner crack of CC slab and the ratio of the down graded hot rolled plate and coil can be effectively reduced by implementation of a series of technological measures such as adopting the soft cooling schedule in both the mould and the secondary cooling zone, maintaining a constant casting speed, controlling the fluctuation of the mold level in 3 mm, using suitable narrow taper of mould, improving the basicity of powder, ensuring the precision of guiding roll in the segment section as well as controlling the deviation of roll gap within the limit of 0.5 mmand the deviation of mould oscillation within ±0.3 mm. Related Articles | Metrics Cited: Baidu(4) Select Control of oxide inclusion for low carbon and low silicon steel Steelmaking    2012, 28 (2): 29-31.   Abstract （407）            Knowledge map    Save In order to improve the castability of molten steel and avoid casting break by nozzle clogging the processes of converter such as the poststirring, top slag deoxidization and carbon deoxidization by RH are optimized on the basis of the production practice in low carbon and low silicon steel in Chongqing steel. Since the process improvement, the quality fraction of BOF end point oxygen has been decreased by 127×10-6, the quality fraction of FeO and MnO in the slag reduced to less than 5%, addition amount of ferroaluminum decreased by 0.38~0.43 kg/t, oxide inclusion decreased effectively and the quality fraction of T.O controlled in the range of （14~25）×10-6. Production practice shows that by adoption of “BOF→RH→CC” processing route in production of low carbon and low silicon steel the cleanliness of the steel can be improved and the continuous casting heats of single tundish reaches 18 heats. Related Articles | Metrics Cited: Baidu(3) Select Development of high-quality 28MnCr5 gear steel Steelmaking    2012, 28 (2): 32-35.   Abstract （952）            Knowledge map    Save 28MnCr5 gear steel is successfully developed by adoption of “EAF→LF→VD→CC” processing in route in Laiwu Iron and Steel Group Co., Ltd. By precise control of C, Si, S and P in steel the liquid steel in conformity to the chemical composition specification can be obtained. Experimental results show that the high quality 28MnCr5 gear steel slab for automobile use (w(T.O)≤15×10-6) can be refined and the type, morphology and size of the inclusions in steel can be effectively controlled and demand of hardenability for the steel can be met as well. Related Articles | Metrics Cited: Baidu(1) Select Quality control on thin slab of low-carbon steel by BOF→RH→CSP process Steelmaking    2012, 28 (2): 36-40.   Abstract （428）            Knowledge map    Save The quality defects such as occurrence of non-metal inclusions, edge breaking and edge cracking exist in the low carbon steel sheets produced by processing route of “BOF→RH→CSP” in Lianyuan Iron & Steel Group and in CSP serious nozzle clogging also emerges as well. By analysis on factors affecting the quality of the CC slab a series of process measures such as optimization of converter refining, RH refining,Ca treatment on hot metal and Argon soft stirring have been put forward. Since implementation of those measures the average continuous casting number of low carbon steel reaches over 15 heats and quality of the sheet prominently improved. Related Articles | Metrics Cited: Baidu(1) Select Optimization of nitrogen control process in refining wheel steel Steelmaking    2012, 28 (2): 41-43,4.   Abstract （862）            Knowledge map    Save The full course of wheel steel production in Hanbao Steelmaking Plant of Handan Iron & Steel Group Co., Ltd has been traced and variation of nitrogen content in each and every operating process in production of the wheel steel by “LD-LF-CC route studied and analyzed. By optimization of the control process and implementation of nitrogen control in the full course the w(N) in the finishing products of the wheel steel confines within the limit of 45.00×10-6 and 31.61×10-6 is average. Thus quality of the wheel steel is improved. Related Articles | Metrics Select Industrial test on hot metal desiliconizing process by slag washing Steelmaking    2012, 28 (2): 44-47.   Abstract （425）            Knowledge map    Save An industrial test on hot metal desiliconization process is unfolded in Chongqing Iron and Steel Co.,Ltd. Results show that desiliconization rate can reach 52.69 %by adoption of slag washing process for hot metal desiliconization and the primary factors affecting the desiliconization results are amount of desiliconizer addition, original silicon content and rate of siliconizer feeding. Hot metal temperature drop and foamization of desiliconization slag problems are discussed as well. Related Articles | Metrics Cited: Baidu(3) Select Study on silicon control of low carbon and low silicon Al-killed steel in refining process Steelmaking    2012, 28 (2): 48-51,6.   Abstract （393）            Knowledge map    Save n order to check silicon pick up in the low carbon and low silicon steel in smelting process，silicon content control in LF refining in CSP process at WISCO has been studied by industry experiments. The results show that silicon pick up happens primarily in LF refining process. Calcium treatment process is also an important factor affecting silicon pick up in molten steel besides the quantity of slag in tapping and soluble Al content in molten steel.Thermodynamic calculation shows that at the end of refining silicon pick up still carries on because reaction between AlS in molten steel and SiO2 in the slag is far from the equilibrium and the reducibility of Ca for SiO2 in the slag is far more greater than that of AlS and silicon pick up can be alleviated by properly readjustment of the content of SiO2in the top slag. Related Articles | Metrics Cited: Baidu(3) Select Effect of Ca-treatment on sulphide inclusions in 20CrMo gear steel Steelmaking    2012, 28 (2): 52-55.   Abstract （460）            Knowledge map    Save On the basis of thermodynamic calculation the process conditions of Ca-treatment of the sulfur bearing 20CrMo gear steel is analyzed and the sample of rolled stock taken from the Ca treated sulfur bearing gear steel is studied in a specific Plant. Results show that in the liquid steel Ca treated in a RH device the sulfide inclusions and calcium aluminates bind together and form the spindle shaped low melting compound inclusions. In the meanwhile control of w(O) in steel below 10×10-6 before Ca-treatment is more beneficial to the full modification of Al2O3and sulfide by the added calcium and to the formation of oxide and sulphide compound inclusion with MnS as its nucleus and after Al deoxidation S segregation can be reduced in the period of solidification only if w(AlS) in steel is adjusted to 0.015 %～0.025 %and Si-Ca cladded wire is fed at higher temperature. The morphology of inclusions in the Ca treated sulfur bearing gear steel are acceptable and all indicators of properties can meet the requirements of customers. Related Articles | Metrics Cited: Baidu(2) Select Physical simulation of sink-vortex slag entrainment in 120 t ladle Steelmaking    2012, 28 (2): 56-59,7.   Abstract （424）            Knowledge map    Save By way of water modelling the slag entrainment process in ladle casting of a 120 t ladle is observed. The effects of slag quantity in the ladle and nozzle diameter of the ladle on the height of slag entrainment are studied as well. Results show that when the slag amount in the ladle rises from 0 % to 1.0 % the onset height of slag entrainment is reduced by 57 % and height of stable vortexing funnel slag entrainment reduced by 56 %; as soon as the slag amount reaches 7.0 % from 1.0 %the onset height of slag entrainment is raised by 63 %and the height of the stable sinkvortex raised by 62 %; and as the flowrate of ladle nozzle accelerates to 22.465 m3/h from 2.884 m3/h the onset height of slag entrainment increases by 60 % and as the flowrate of ladle nozzle rises to 19.211m3/h from 2.361 m3/h the stable height of sinkvortex increases by 75 %. Related Articles | Metrics Cited: Baidu(2) Select Research on simulation of liquid steel flow in a ASF billet 8-strand continuous casting tundish Steelmaking    2012, 28 (2): 60-64.   Abstract （432）            Knowledge map    Save Three-dimensional flow field of molten steel in a 8-strand continuous casting tundish is investigated by numerical simulation method and then the results are verified by water model experiment and industrial production. The simulation result shows that the baffle and inhibitor in ASF tundish can improve the flow coditions and temperature distribution of liquid steel remarkablely. The flow conditions will be much better if double dams are installed in the tundish. Since there are four circulation zones for flowing of the liquid steel not only mixability of the liquid steell is improved, but also the temperature distribution of the liquid steel in the tundish is more homogeneous and low temperature zone is much less as well. Water model experiments show that the similarity of the flow characteristics of each strand can be prominently improved by installation of inhibitor and baffle in an empty tundish and the flowability of the liquid steel can become much better if double dams are further added in the tundish upon the above mentioned base. The results of numerical simulation are completely in agreement with that of the water modelling. Beside the expected purposes have also been achieved in the industrial production. Related Articles | Metrics Cited: Baidu(1) Select 李峰1 ，白月琴1，唐建平2，兰月光2 Steelmaking    2012, 28 (2): 65-66.   Abstract （462）            Knowledge map    Save In the present paper measures for control over aluminium content in rail steel used for high speed train are studied by calculating. Results show that in the process of LF refining the Al2O3in the slag can be reduced to the liquid steel by silicon in the heavy rail steel, thus resulting in an increase of aluminum content in steel. And therefore by controlling the basicity and AlAl2O3content of the slag at the low level and keeping the silicon content in the steel on the bottom line the aluminum content in steel can be held at a lower level. Related Articles | Metrics Select Fundamental research on CO2 and O2 mixed injection stainless steelmaking process Steelmaking    2012, 28 (2): 67-70.   Abstract （522）            Knowledge map    Save Through a great number of theoretical calculations and laboratory tests the COMI process (CO2and O2 mixure blow refining) has been successfully applied into the stainless steel refining by the research personnel of University of Science & Technology Beijing. Experimental results show that COMI process not only has little influence on the normal refining of the stainless steel, but it can also promote decarbonization and preservation of chromium and reduce nickel loss. All those are beneficial to improvement in the quality of stainless steel. Besides, in this process a part of CO2 can be used to replace argon gas and O2, and thus the production cost per ton steel can be saved by about 20 to 45 yuan and further more reclamation of CO2 is in favor of development of green carbon economy. Related Articles | Metrics Select Analysis on control of oxide inclusions in the valve spring steel 54SiCr6 at home and abroad Steelmaking    2012, 28 (2): 71-74.   Abstract （419）            Knowledge map    Save Through comparison and analysis on the size and composition of the oxide inclusions in the valve spring steel 54SiCr6 at home and abroad it's found that the size of oxide inclusions is well controlled in A Steel Work at home. However there is still a certain difference in the field of plasticity of the steel in comparison with the foreign steel works. The primary cause is determined to be occurrence of over greater amount of Al2O3 in the oxide inclusions. The plasticity of oxide inclusions can be improved by adopting a few measures to reduce the AlSin the liquid steel. Related Articles | Metrics Cited: Baidu(1) Select Optimization and practical application of measurement method for dendrite arm spacing of continuous casting slab Steelmaking    2012, 28 (2): 75-78.   Abstract （511）            Knowledge map    Save The present paper introduces tests on the optimization of the measurement method for dendrite arm spacing in the continuous casting slab and its application. By analysis on the solidification cooling process and data acquisition of the CC slab the typical region of dendrite arm spacing is determined and a scientific method for measurement on the dendrite arm spacing is established. By application of this method in the CC slab production the law of change of dendrite arm spacing of CC slab with the variation of secondary cooling intensity can be quickly and accurately determined. By adjustment of the intensity of the secondary cooling of continuous casting the size of the primary and secondary dendrite arm spacings can be controlled and thus the purpose of alleviation and removal of the slab cracking defect and improvement in the quality of the slab is achieved. Related Articles | Metrics Cited: Baidu(1) Select High efficiency low cost platform for clean steel production practice Steelmaking    2012, 28 (3): 1-6,10.   Abstract （467）            Knowledge map    Save According to the theory of “metallurgical process engineering”, the present paper described analysis on the function of the high efficiency and low cost production, platform for clean steel and ironsteelHR interface technology of the main processes of Jingtang Iron and Steel Plant. The Plant has been running very smoothly as a whole for two years since being put into commissioning and the purpose of process optimization realized as well. Total DeS, DeSi, DeP ratio steadily maintains on above 80 % and in the meanwhile the material flow rate is also accelerated and the target of 90 heats per day realized, energy loss reduced, tapping temperature lowered markedly and all kinds of material consumption reduced dramatically. In comparison with the normal level the consumption of the auxiliary material is reduced by 30 %. Related Articles | Metrics Cited: Baidu(6) page Page 1 of 3 Total 114 records First page Prev page Next page Last page