Shandong fulun Steel has built the first two-strand slab continuous caster for producing products with different sections. The functions and equipment structure together with the hydraulic and electric control principle of taper dynamic balance technology of the slab continuous caster were presented. The quantitative relationship of pressure reduction on mold broadside, disc spring pre-tightening force and the static pressure of liquid steel in the process of casting was derived. From the application of this technology on October 9, 2013 to November 12, 2013, 41 860 t slab has been cumulatively casted, 14 heats on average were continuously cast for every casting sequence, and the maximum casting speed is 1.4 m/min. In the meantime, no taper change happens and the left and right tapers are always kept in ±0.5 mm. The internal and external qualities of slab are excellent, and actual application effect is satisfactory.

Isothermal compression experiments of SAE4137 steel were performed on an MMS-200 thermal-mechanical simulator at the strain rate ranging from 0.1 to 10 s-1, the deformation temperature ranging from 900 to 1 150 ℃ and the maximum height reduction of 70%. On the basis of the experimental results, dynamic material model and Murthy flow instability criterion, the processing maps for SAE4137 steel were constructed at the different true strains. The stable regions, flow instability regions and the recommended processing region were obtained for SAE4137 steel. Based on the analysis of microstructure and the practical condition of making intermediate billet (215 mm×235 mm) into [?]150 mm large bar through 4-pass finishing rolling in Nanjing Steel, the surface defect and its position of SAE4137 bar in production process were predicted.

The effect of different deformation conditions on the deformation behavior of 45 carbon structural steel at low temperatures was studied using Gleeble-1500 thermal-simulation machine. Experimental results show that peak stress increased with the decreasing of deformation temperature and the increasing of strain rate; dynamical recovery occurred when strain rate [ε]≥0.01 s-1, and deformation temperature [t]＜500 ℃; dynamical recrystallization occurred when strain rate [ε]≤1 s-1, and deformation temperature [t]≥500 ℃. The flow stress models at work harding-dynamical recovery stage and dynamical recrystallization stage were both established based on the Sellars-Tegart equation. The parameters in these models were fitted according to the experimental results. The stress-stain curves of both dynamic recovery style and dynamic recrystallization style were successfully predicted. The straightening force at low temperature of 45 steel plates in the industrial trial was predicted, and the results matched well with the measured values.

The fracture morphology of creep rupture tested samples and microstructural evolution was investigated at 600℃, and the creep rupture mechanism of a T23 steel used for ultra-supercritcal power generations was discussed under different stress levels. The results show that, under condition of high stress level, the creep rupture mechanism is similar to the ductile fracture at room temperature, and the cavities nucleate mostly at sites of the inclusions, behaving intragranular fracture. However, under low stress level, the creep rupture mechanism is brittle fracture occurred along the grain boundary, and the cavities nucleate mostly at sites of the second-phases, behaving intergranular fracture.

Zinc is the closest nonferrous metal with steel, to study the volume of zinc resources in scrap, galvanized steel sheet, which takes the largest output in galvanized steel products, is taken for example to study the substance path with steel. A mathematical model of galvanized steel sheet end-of-life recycling and volume of zinc with it was established, according to the corrosion law of galvanized steel sheet using in different environments. Recycling resource volume from scrap galvanized steel sheet was computed under different service life in China. The results show that the life of waste recycling has the maximum impact on zinc resources in Chinese scrap galvanized steel sheet. The longer it scarps recycling, the less current zinc resource volume. The most cumulative volume of zinc resource from scrap galvanized steel sheet can reach 800 thousand tons to 2010 in China.

The alkali metal has a positive catalytic effect on coke gasification reaction. And coke gasification characteristics affect the energy utilization of blast furnace. The effect of CaO, which was added to coal before carbonization under laboratory conditions, on the strength, gasification temperature, average reaction rate of coke and its activation energy was researched. According to the quantificational research results shown when add 4% CaO component into coke, which strength decrease as much as 7%, gasification temperature decrease 80℃ at most, average gasification rate increase maximum and activation energy 30% smallest than that of coke with no addition.

Three 403 steel bars of different compositions were searched, which were produced by 200kg VIM furnace and forged into 120mm. Mechanical and magnetic properties were tested after heat treatment 950-1000℃×1h OC+720-750℃×3h OC. The results show that, 403 steel bar with higher Ni or N has higher strength, magnetoconductivity and toughness especially. Compared with test steel bar with higer Ni, bar with higher N has higher magnetic induction in lower magnetic field intensity, while lower magnetic induction in higher magnetic field intensity. Strengthening mechanism was searched and the conclusion can be made to guide the production of this type steel for rotator.

Gas quenching steel slag was adjusted the ingredients and reconstructed by CaO, and these slags were heated some time at different temperatures. The law of crystallization and growth of C2S in those slags with different CaO contents was analyzed by metallographic microscope and metallographic analysis software. The law of isothermal crystallization kinetic of C2S in gas quenching slag affected by CaO was studied by JMA equation. The results show that the C2S crystalline amount shows a decreasing trend after the first increase with the increasing of CaO content. When alkalinity of slag is 3.25 and thermostat time is 30min, the C2S crystalline amount reaches a maximum of 64.06%. When alkalinity of slag os 3.25, the isothermal crystallization activation energy of C2S reaches a minimum of -6.36kJ/mol, and the energy barrier of isothermal crystallization of C2S reaches minimum, which is most conducive for the crystallization of C2S.

As the construction and application of heavy equipment such as automobile, high speed railway, precision machine and wind power, high requirements including product quality, long fatigue life and reliability have been proposed for the bearing. The bearing steel is the key point to influence the bearing quality, in addition to the structure design and manufacturing precision. Requirement and property of bearing in field of high speed railway, wind power and tunnel boring machine (TBM) were analyzed. Development of bearing steel was introduced. Quality control principle of bearing steel was discussed to achieve the aim of clean, homogenized and refined microstructure. Clean steel is obtained by precise composition, low harmful element amount, carbide eliquation, segregation, solidification defects and inclusion control during melting and solidification. Homogenized and refined microstructure was obtained by controlled rolling and controlled cooling during rolling or forging process, to meeting workability of subsequent process.

Based on the physical-chemical properties of injecting coal in Bayuquan, the mixture schemes of different injecting coal proportion with different coal, which was obtained through optimum design, was used in ironmkaing practice of No.2 BF. The coal ratio of 2 BFs was increased 4.44kg/t（No.1 BF） and 5.78kg/t(No.2 BF), respectively. And the fuel ratio was decreased 14.94 and 13.20kg/t, respectively. This method can reduce the fuel consumption and can improve BF performance compared with traditonal ones.

Thickness measuring technology by laser was applied to practical production, which can realize quantification of erosion parts and real-time control of converter lining. Therefore, vulnerable parts of the furnace would be found and repaired timely to maintain converter lining. According to the determination, the weakest location of the lining was the load part of the facet of the converter in the early campaign life, while was the section of the trunnion in the middle campaign life, and erosion of lining was severe in the later stage of campaign. The lining thickness range can be divided into three parts, when campaign reached mid-late period, the thinnest lining was still above the stable range, and furnace life was more than economic life (20-23 thousand heats).

The stirring mechanism of bottom blowing CO2 was investigated and some exploratory experiments were conducted with different proportion of CO2 during the 75t LF refining process in industry. The results show that bottom blowing CO2 can intensify liquid steel agitation and the desulfurization efficiency increases from 49.7% to 65.1%, the mass fraction of FeO is less than 0.5% in the slag so it can meet oxidizing requirements. Compared with bottom blowing Ar, the equal yield density of inclusions decreases and the cleanness of steel is improved, so it is possible for LF to use CO2.

Using nonlinear elastic-plastic finite element method, a 3D FE simulation model of 1450 HC rolling process was developed with the nonlinear FE software MSC.Marc. Based on the model, a large amount of models which contain different rolling parameters was simulated and the strip crown was obtained. The effects of different rolling parameters, strip and rollers parameters on the strip crown were investigated and the main rules were mastered. The simulation results of the strip crown are served as the sample database of BP neural network by which the prediction model of cold rolled strip crown was built. During the training, an improved arithmetic was used in the BP neural network. Practice had proved: an improved arithmetic of BP neural networks improves the speed of learning and builds up the feasibility of arithmetic. The problem that the finite element method is time consuming and difficult to be used to the online flatness control is solved, and the precision of flatness online control is enhanced by this method.

The west part of the third west-east nature gas transmission line traverses some active geological fault and strong earthquake region in which case 1219mm×26.4mm X80 high-deformable line pipe is required for strain-based design. The effects of ferrite volume fraction and grain size of 1219mm×26.4mm X80 high-deformable ferrite and banite dual phase steel on the longitudinal yield strength, uniform elongation and Charpy V-notch energy was investigated. Meanwhile, the relationship between microstructures and mechanical properties, the effects of pipe forming and aging on longitudinal mechanical properties were described through analyzing the industrial data. It was found that the tensile property is not sensitive to the ferrite volume fraction. However, less ferrite volume can promote the improvement of Charpy V-notch energy. Ferrite grain refinement plays an important role for improving tensile properties and fracture toughness. It is necessary to refine the polygonal ferrite grain size.

Tests which accord to IMO on simulated inner bottom conditions in cargo oil tanks (COT) was adopted to compare and analysis the corrosion mass loss and corrosion morphology of conventional and corrosion resistant ship hull steel, and deeply studied the corrosion behavior at different temperature. The results showed that, temperature had significant effect on the corrosion behavior, with the rise of the temperature, the number of pits increased, the depth of pits increased and then decreased, reaching the peak at 45℃. Spot corrosion behavior conventional and corrosion resistant ship hull steel was greatly different. The value of h/D (depth/diameter) increased with temperature rising, while the value of corrosion resistant steel decreased The addition of corrosion resistant alloy elements apparently decreased the corrosion rate and the number of pits. The expanded mode of pits was also improved with the addition of corrosion resistant alloy elements. The expanded mode of pits was changed from along the depth direction vertically to along the surface direction laterally.

The development general situation of the special steel industry abroad was introduced, and the production mode and industry characteristics of industrial developed countries at present stage were analyzed. Through the reorganization and integration in the past decades, reasonable production scale and clear market positioning has formed in developed countries, they preferred to focus on the production of high quality and high value-added professional products, resulting in a number of advanced special steel enterprises, improved the international competitiveness and market share. In addition, the development trend of processing technology and some development direction of special steel products worth noticing was also introduced.

CaO is a kind of pulverized coal combustion improver which is suited for the blast furnace. It is adsorbing volatile, making fixed carbon overheat at local regions and increasing carbon activity, in this way, pulverized coal can take fire at lower temperature by DTA and TG curves analysis. Collecting unburned coal through simulating combustion conditions of blast furnace, analyzing XRD, IR spectrum and SEM, the microcrystalline parameters of unburned coal increased, the height and diameter of aromatic slices will increase 0.0024nm and 0.0362nm respectively as CaO joined.The absorption peak of unburned coal powder adding CaO is more obviously than raw coal in 1500cm-1 and 3400cm-1. The particles size of unburned coal powder reduced 2.67μm by adding CaO, the morphological appearance become irregular.

To realize controlled cooling of seamless tube between sizing and straightening in the production process of automatic plug mill, the laws of microstructural and mechanical properties change of rolled No.20 tube during the cooling process were investigated using numerical simulation method under the different cooling conditions. Firstly, after the cooling curves of steel probe in the different cooling mediums were measured, the relationship of heat transfer coefficient of probe and work piece’s temperature was obtained by programming and solution using the basic principle of inverse heat conduction method. And a predict system of temperature, phase transformation and mechanical properties in the cooling process of tube was established using finite difference method. The cooled phase and properties of tube were analyzed in the different cooling processes. Finally, the air cooling experiment of tubes was carried out and the temperatures at different time of cooling and mechanical properties of tubes were measured. The simulated results are in good agreement with the measured data. These works lay a foundation of controlled cooling of seamless tube.

The cross section microstructure of the steel bar with micro alloying controlled rolling and controlled cooling technique as well as the reasons of different compositions to the microstructures were investigated. It is found that the segregation of elements (P,Si and Mn et al.) distributes like stripping which results in the such stripping microstructure for steel 20MnSi and 20MnSiV during rolling. The 20MnSiNb steel can not be recrystallized below 1050℃ for the pinning by Nb and its compound containing C and N elements. The proeutectoid ferrite is formed homogemously in grain boundaries of deformation austenite and interior of deformation zone, then, the pearlite belt is separated out in grain boundaries of deformation austenite (between the grain boundaries proeutectoid ferrite and austenite). The bainite strip is generated in the grain of deformation austenite during last cooling stage. The proper order precipitation of the microstructure of the samples shows as follow: grain boundaries of deformed austenite and deformed band of deformed austenite, segregation of elements, grain boundaries of recrystallization austenite.

The evolution of mechanical properties and microstructures of a low-alloy steel containing low C, low Mn, high Cr and high Nb were studied after thermo mechanical control process and tempering process after the rolling, respectively.Moreover, resist-hydrogen induced cracking (HIC) tests were carried out on the tested steels. The results show that the mechanical properties of tempered steels are improved comparing with of rolled steel. After tempered at 600℃ for 1h, its yield strength is increased 100MPa, and tensile strength is increased 50MPa, but the toughness almost has no reduction. The type of microstructures after tempering process is similar with of rolling condition, which is still mainly composed of acicular ferrite, and a small amount of quasi-polygonal ferrite. However, M/A constituent gradually reduces with the increasing of tempering temperature. The results of the HIC test indicate that all the tested steels can meet the requirements of standards, and the resist-HIC performance is improved after the tempering treatment.

The reduction of ilmenite was more difficult than the common iron ore in thermodynamic aspect. The dynamic study shows that the reduction rate could be accelerated when ilmenite powder is refined further. The best reduction temperature of ilmenite by powdered carbon should be 900-1100℃. Carburization is favorable for ferrite grain growth. The more carburization is, the better ferrite grain growth is. The outfield has played a noticeable role in ferrite grain growth, which could provide the best condition for the separation between titanium slag and iron. The iron nugget formed by ferrite grain growth and high titanium slag could be obtained by simple magnetic separation. With low reaction temperature and elimination of the electric smelting process, this technology is a new method for an efficient utilization of resources and energy. The efficient utilization technology of ilmenite has the advantages of high efficiency, low-energy consumption, low investment and low cost.

Fixture wire still is the largest varieties of steel consumption. The output of rebar is more than 160 million tons in 2011. development of new varieties, reducing production costs, improving the grade of strength and the quality of existing fixture wire, accelerating the promotion of the new varieties and new technologies, revising of metallurgical standards and architectural design specification are currently facing major problems. The developed status of the fixture wire varieties, relevant performance indicators and international technology trends were analyzd and reviewed.

The sintering basic characteristics of five kinds of iron ore and blending iron ore in Handan Iron and Steel Co. Ltd. were determined. The results show that the effect of Brazil coarse ore on the assimilation temperature and liquid phase fluidity of blending iron ores is the greatest, effect of Australia iron ore on the binding phase strength is the most. Based on the binding phase strength, considered the assimilation temperature and the liquid phase fluidity comprehensively, the optimized ore-blending is that, 30%-35% Australian iron ore + 15%-20% Hanxing concentrate + 20%-25% Brazilian coarse ore + 10%-15% Yandi ore + 5%-10% North Africa ore. The sintering basic characteristics of single iron ore has mutually complementary relationship, but the sintering basic characteristics of blending iron ore can’t determined by a single linear calculation.

Wettability between molten slag and MgO-C refractories was investigated by sessile drop method at high temperatures. When the slag was contacted directly with the refractory, the slag stayed infusible. When the slag was separated by a small alumina crucible from the refractory, wettable reaction occurred. Contact angles of molten slag and MgO-C refractory in reactive wetting decreased monotonously with the increase of the temperature, while the area spreading rate linearly increased. FeO in the slag is reduced to Fe by the carbon in substrate or CO in the atmosphere, which results in the increase of the melting point (or softening temperature) of the slag. Molten slag penetrates pores and cracks on the surface of MgO-C refractory, then yellow permeability layer including high melting-point phase which protects the lining of converter is generated by the reaction of Fe2O3 in slag and MgO, which provides a theoretical basis for optimizing slag splashing process, controlling the slag composition and selecting refractory.

Considering the weight of shape detection roll and the strip tension, using a sine wave or a spline curve to virtual zero deviation of each channel, the dynamic zero compensation model was established based on the cut-off point method for deflection changes of the shape detection roll. For offline zero deviation by the shape detection roll’s mass, the virtual sine cut-off point method was designed to compensate the offline zero deviation. For the online zero deviation by the dynamic high tension, the zero deviation was fitted by the spline curve to do it. Zero deviation fitting curve was subtracted from the measured curves, then more stable radial pressure value or the shape value can be obtained. In the application process, the recursive smoothing method can be used to make it more reliable for reflecting the actual shape condition of online strip. The measured datum show that the original waveform AD zero deviations of each channel reduces from 600 to within 50 after compensation, and the radial pressure decreases from 130N to 10N. So the zero compensation method has a great significance to improve the shape detection accuracy and shape close-loop control accuracy.

The high radiative coating technology was used in the coke oven 5 in Jiuquan Steel Co., The comparison test were conducted under different conditions in between the coke oven with and without coating. The results show that the heat transfer efficiency was increased 6.35% in coke oven 5, and the central temperature of coke cake increases 14℃, the flue gas temperature decreases 23℃ and saves coke oven gas 420.48×104 m3/a and the energy saving rate is 3.32%. The effective thermal efficiency of coke oven is increased 1.99%. The energy consumption for the coking process decreases 81.8kJ/kg coal（with 7%H2O）, and CO2 emissions reduces 132.5×104 m3/a. Obvious economic and social benefits can be obtained.

Reducing annealing furnace is the key equipment of CGL of cold rolled steel strips. In China, high capacity reducing annealing furnaces usually are imported at high cost. In order to manufacture such furnace domestically, the reducing annealing furnace for Jigang 250000 t/a CGL was studied and developed successfully based on the experience from previous designing and operation practice and digestion of advanced technique abroad. It was proved by production that the performance of this furnace is excellent and the technological requirements of CGL are satisfied completely.

A new work roll contour is advanced which is a linear variable crown (LVC) roll. This roll contour can realize linear ratio of gap crown and strip width. Gap adjustment area and gap transversal stiffness as two basic control capabilities for strip profile are used to evaluate the strip shape control ability of LVC work roll. Then LVC work roll was applied to real production. The results show that LVC work roll contour has good availability according to calculation and comparison.There is definite innovation on the research of work roll contour.

To reduce the rebar straightening power on conventional straightening machine, a new mould straightening principle with rotatinghub is proposed. According to this principle, three steel balls which rotate in any direction are mounted in a mould to transform sliding friction between rebar and balls into rolling friction. In this way, the force pushing rolls and straightening power are decreased greatly, and quality of straightened rebar can be obviously improved. The tolerance in straightness can be less than 1 mm per meter. The force and performance of this straightening machine are analyzed and calculated for designing.

The strain aging of boron containing lowcarbon steel wire rods was studied. The results show that adding appropriate boron in lowcarbon steel could slightly reduce the increment of yield strength, which is caused by static strain aging. The increase of tensile strength caused by dynamic strain aging was hardly reduced while ［B］s content was below 0.0029% and ［B］s/［N］<0.4. The increase of tensile strength caused by dynamic strain aging could be decreased obviously when ［B］s is in range of 0.005% to 0.010% and ［B］s/［N］ ≥1.0，so that the drawing performance of lowcarbon steel wire rods could be improved.

he serial bellless top with two coaxial vertical was adopted on 1750 m3 BF of Ji’nan Iron and Steel Co., Ltd.. In order to ensure the stable operation of blast furnace and establish operational manual, a model of burden distribution was developed and verified in practice. Based on the principle of steadiness and the theory of coke terrace, a reasonable orecoke ratio can be established. Once coke terrace has been determined, ore distribution matrix can be regulated. In this way, the burden distribution matrix was optimized and the operation of BF was improved. The operational indexes have been improved continuously.

For CSP thin slab caster at Zhujiang Steel, a comprehensive mathematical simulation concerning fluid flow, fluctuation of bath surface, heat transfer and solidification of melt was performed with given SEN and measured heat fluxes. It was found that the circulation of liquid steel, in which two uppervortexes occupy most space, is totally localized in the funnelpart of mold. The fluctuation of bath surface is caused by upvortex streams impinging on surface and deviating from the surface, and secondary vortexes exist below meniscus 100 mm off mold narrow faces. Except that there is obvious superheat at lower sides of SEN, the temperature of liquid steel in mold is around the liquidus, and the surface temperature of slab and growth of solidifying shell are affected by streams from SEN, and the hottest zone on slab surface is below meniscus near mold narrow faces.

The genetic programming approach was proposed to predict temper embrittlement of rotor steel (30Cr2MoV). Two independent data sets were obtained experimentally: training data and verifying data. Peak current density of reactivation measured by the potentiodynamic anode polarization method, temperature of electrolyte, the chemical composition of steel (Jfactor), Cr content and the grain size of steel were used as independent variables, while fracture appearance transition temperature as dependent variable. On the basis of training data, the optimum model was obtained by genetic programming, and the accuracy of it was verified with the verifying data. The prediction error of the model is within ±20 ℃. The accuracy of this model is better than that of the model obtained using multiple linear regression method. The results suggest that, the model obtained by genetic programming is feasible and effective.

Based on the Danieli DanExpert EAF Suite with several modules,a real time dynamic updating of set points at any change in process status allows for an increased productivity by improving consistency of EAF practices and contributes to lowering transformation costs.

The numerical simulation method was used to study the heat transfer and temperature distribution of rolling piece during hot strip rolling. According to the temperature measured in production, a statistical model of interface heat transfer coefficient (HTC) for prediction of thermal evolution of rolling piece in roll gap was developed; and some features of the thermal evolution and temperature distribution on the cross section of rolling piece in roll gap are analyzed. The results show that there is a good agreement between the values predicted by the model and measured ones; the interface HTC between rolling piece and work roll is dependent on the mean rolling pressure as well as the rolling speed; and there is a significant temperature gradient on the cross section of rolling piece in roll gap.

The difference of the cost and quality of liquid steel produced by EAF and BOF is compared. The application of CoJet at Baosteel and the development of automatic EAF steelmaking are introduced. Finally, several R&D projects at Baosteel of environmental protection concerning EAF steelmaking are introduced.

Scheduling at BOF shop with some BOFs and casters is a problem. A new scheduling method based on MAS mechanism is introduced. According to the equipment and technological parameters, the simulation model of scheduling of steelmaking and continuous casting process based MAS was built. The structure, scheduling algorithm and scheduling strategy of MAS model were studied. Then the model was tested with real production schedule. The results show that the schedule, location and time of every heat can be determined simultaneously, so the method is effective and applicable.

In spite of that charge quality for sintering was improved through using low silicon sinter, but the strength, size and metallurgical properties of sinter were deteriorated. It was found that serpentine addition makes liquid phase and strength increased, return fine and solid fuel consumption reduced and reductionsoftening behavior of sinter improved, in spite of small increase of SiO2 in sinter. Due to high Al2O3 in blast furnace slag, and the influence of MgO in sinter on it’s sinter strength was studied, the industrial experiment showed that replacement of dolomite with lightly fired dolomite partly has small effect on productivity, but the drum strength is increased, solid fuel consumption is reduced, the productivity of BF has increased with lower coke rate and the fluidity of slag is higher. Spraying with 3% CaCl2 reagent is very effective for RDI（reduction degradation index）.

The basic approaches to improve gas recovery ratio were analyzed in theory based on converter gas recovery system of Baosteel No.2 steel making plant. The effect of following factors such as converter conditions, raw material supply, air suction rate, recovery conditions, and intensity of oxygen blowing on converter gas recovery ratio was studied. And the effects of air suction rate, recovery conditions and intensity of oxygen blowing are remarkable. The physical measures are put forward for modification of hard and soft ware of converter gas recovery system, and good results can be achieved.

For the rolls of the 1200 HC(high crown) 6high reversing cold mill, the measures of precaution and elimination of roll failures were put forward from some aspects such as roll inspection, roll grinding and assembly etc. Firstly, advanced inspection methods such as magnaflux method, portable roll surface rigidity detector, macrostructure analysis and so on should be applied to find out the roll defects, which are difficult to be observed with naked eyes. Secondly, some measures, such as modifying cooling and lubrication systems and filtrating equipment, designing reasonable grinding amount and roll changing period, and machining the compound chamfer angles at two shoulders of the intermediate rolls and backup rolls etc., can reduce roll consumption, and increase roll campaign. After modification, the roll changing period was increased from 100 km to 160 km, the roll defects and consumption (including the intermediate rolls and backup rolls) were greatly decreased, and the hour output of mill was improved by 11.1%.