Consideration of green intelligent steel processes and narrow window stability control technology on steel quality

In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. Based on both domestic and global research, functional analysis, reasonable positioning, and process optimization of each aspect of steel making are expounded. The current state of molten steel quality and implementation under narrow window control is analyzed. A method for maintaining stability in the narrow window control technology of steel quality is proposed, controlled by factors including composition, temperature, time, cleanliness, and consumption(raw material). Important guidance is provided for the future development of a green and intelligent steel manufacturing process.

Modeling the austenite-ferrite transformation in microalloyed steel P510L

Based on experimental results, the transformation kinetics and cooling characteristics of low-carbon steel were analyzed and modeled to quantitatively link the operational parameters of a process with the properties. From the continuous cooling transformation results, comparisons of the start temperature of austenite-ferrite transformation among three models were analyzed, and the optimal lnk and n, which are the parameters in the Avrami equation, were determined by applying two regression models at different cooling rates. The transformation kinetics during continuous cooling was determined. Furthermore, reasonable agreements between experimental results and predictions were obtained, which can demonstrate the rationality of the established models.

Simulation of recrystallization based on EBSD data using a modified Monte Carlo model that considers anisotropic effects in cold-rolled ultra-thin grain-oriented silicon steel

A Monte Carlo Potts model was developed to simulate the recrystallization process of a cold-rolled ultra-thin grain-oriented silicon steel.The orientation and image quality data from electron backscatter diffraction measurements were used as input information for simulation.Three types of nucleation mechanisms,namely,random nucleation,high-stored-energy site nucleation(HSEN),and high-angle boundary nucleation(HABN),were considered for simulation.In particular,the nucleation and growth behaviors of Goss-oriented({011}<100>)grains were investigated.Results showed that Goss grains had a nucleation advantage in HSEN and HABN.The amount of Goss grains was the highest according to HABN,and it matched the experimental measurement.However,Goss grains lacked a size advantage across all mechanisms during the recrystallization process.

Desulfurizer desulphurization kinetics by the injection method

To obtain a better desulphurization effect in hot metal, suitable desulfurizers should be selected first according to thermodynamics. However, the effect of desulphurization is also strongly affected by kinetics. The conditions of different desulfurizers （Mg, CaC2, and lime） penetrating into hot metal, the rising up velocity in iron melt, residence time, and dissolving time are theoretically calculated and analyzed. The results are helpful to select the desulphurization process and equipment and to improve the desulphurization effect.

2-Dimensional FEM modeling of macrosegregation in the directional solidification with mesh adaptation

In order to improve the prediction accuracy of macrosegregation channel, an algorithm for dynamic remeshing is proposed. The basic idea is to generate fine elements near the liquidus isotherm. The norm of the gradient of solid fraction is used for piloting the remeshing in the mushy zone; whereas, the objective mesh size in the liquid is considered as a function of the distance to the liquidus isotherm. The efficiency of mesh adaptation is demonstrated by prediction of macrosegregation channel in a case of unidirectional solidification.

Strain-induced martensitic transformation in biomedical Co-Cr-W-Ni alloys

The nucleation,variant selection,and orientation dependence of the strain-induced martensitic transformation(SIMT)process in biomedical Co-Cr-W-Ni alloys were investigated.The experimental results show that theε-hexagonal-close-packed phase was preferentially formed at theΣ3 twin boundaries and high-angle grain boundaries during the tensile process.The theoretical analysis shows that the variant selection of SIMT is governed by Schmid’s law.However,the SIMTedε-phase did not form equally on the two sides of the annealing twins,even though they had the same Schmid factor.This phenomenon is related to the mechanical work developed by the formation of theε-phase.Only the side which has both high Schmid factor and high mechanical work can initiate the SIMT process.A strong<111>fiber texture was formed,and theε-variants tended to appear in grains with orientations close to the<111>and<100>directions during the tensile process.These results can provide theoretical guidance for controlling the SIMT process of Co-Cr-W-Ni alloys to fabricate more reliable stents.

Removal Arsenic(V)Efficiency and Characteristics Using Modified Basic Oxygen Furnace Slag in Aqueous Solution

Basic oxygen furnace(BOF) slag, the solid waste produced in the steelmaking process, is reused in industry, agriculture and environmental treatment. However, as an adsorbent for wastewater, the removal effect of BOF slag on anionic pollutants needs to be improved. In this study, acid and alkali were used to modify BOF slag,and the removal efficiency and mechanism of arsenic(V) with modified BOF slag in solution were studied. The effects of the As(V) initial concentration, solution pH and reaction time on the removal efficiency were determined by batch experiments, and the removal mechanism of As(V) using modified BOF slag was studied by an adsorption kinetic model and isothermal adsorption model and the Fourier transform infrared spectroscopy(FTIR) and X-ray photoelectron spectroscopy(XPS) spectral analysis. The results showed that the slag modified by 15% sulfuric acid had the best removal effect on As(V), while the removal effect of As(V) by alkali-modified slag was not ideal. The removal rate of As(V) by acid-modified slag increased with the increase in the initial concentration, decreased slowly with the increase in pH and reached equilibrium in 180 min. The adsorption kinetic model and isothermal adsorption model of As(V) by acid-modified BOF slag showed that the chemical adsorption was the limiting step.The FTIR and XPS analysis results showed that the silicate and ferrite in the acid-modified slag could remove As(V)in the solution by ion exchange to form an arsenate precipitate. Therefore, modified BOF slag can be used as a potential adsorbent for large scale arsenic polluted waterbody to realize the ecological utilization of industrial solid waste.

Numerical Simulation and Experimental Study on Interlock Deformation for Roll Formed U-Section Steel Piling

The interlock of a roll formed U-section sheet steel piling under loading was analyzed by means of numeri- cal simulation, and meanwhile the tensile failure experiment was conducted. The results indicated that under the same load, the interlock corners of roll formed steel piling are not only the regions with the lowest safety factor, but also the regions with the highest stress; there are two slippages in the tensile instability process of interlock, Each slippage can be regarded as a failure, and different types of failure mode should be used to evaluate the performance of steel pilings according to different applications. Due to the work hardening effect during the roll forming process, the hardness of the interlock material increases by 16% compared with that of the original sheet steel. It was also found that the instability strength obtained in tensile failure test is only 15.6 % of the tensile strength of the original sheet steel.

Influence of temperature and Fe_(2)O_(3)on phosphorus recovery from dephosphorization slag by reduction

The reduction and recovery of P_(2)O_(5)in dephosphorization slag were examined to establish a new recycling process for dephosphorization slag.The dephosphorization slag is obtained from the dephosphorization furnace in the duplex converter process,and the content of P_(2)O_(5) in the dephosphorization slag can reach 9 wt.%.The dephosphorization slag is considered to be a prospective resource of phosphorus due to its high content of P_(2)O_(5).To explore the effects of temperature and Fe2O3 content in slag on phosphorus recovery from dephosphorization slag,the experimental slag was reduced by carbon powder in a resistance furnace.The results show that the temperature and content of Fe2O3 in slag have a significant effect on the reduction in P_(2)O_(5),and the reduction and recovery ratios of P_(2)O_(5) in slags increase with the increase in the experimental temperature and content of Fe_(2)O_(3),reaching 94.41%and 83.09%,respectively.It has been indicated that phosphorus recovery from dephosphorization slag using carbothermic reduction has significant environmental and economic benefits.