查看更多>>摘要：The experiment utilized commercial hot-dip Zn-1.2Al-1.2Mg(designated ZM)coated steel sheets,which were heated in a resistance furnace and held for 5 min at temperatures ranging from 600 ℃ to 900 ℃.The main goal was to investigate the effect of heating temperature on the surface oxidation behavior of the ZM coating.The results show that at lower heating temperatures,the surface oxides are mainly composed of an original thin A12O3 layer,which acted as a barrier preventing further oxidation of the coating.By contrast,at higher heating temperatures,intermetallic phase formation caused Al2O3 layer fragmentation.As a result,the oxide layer of the coating surface became more complex,featuring thicker Al2O3,MgO,and ZnO.
查看更多>>摘要：The optimized stress rupture properties of IN718 are of great interest to the aerospace industry,particularly in the presence of a notch.The deformation mechanisms for the stress rupture properties of IN718 after different heat treatments,using electron back-scattered diffraction(EBSD)as an important tool,were investigated.The notch sensitivity of IN718 was closely associated with the distribution of the 8 phase.When the area fraction(A(f))of the 8 phase was less than 0.56％,the sample failed at the notch;while when A(f)≥2.98％,the notch sensitivity disappeared,and failure occurred on the smooth gauge.Heterogeneous deformation with strain concentrated at the grain boundaries was observed for the notch-and smooth-gauge-failed samples through EBSD analysis.Although intergranular cracking was detected in both cases,the failure mechanisms were different.Grain boundary sliding was the dominant failure mechanism for the notch-failed samples,whereas microvoid coalescence was the dominant failure mechanism for the smooth-gauge-failed samples.
查看更多>>摘要：The detailed reasons for the low impact energy of stainless steel 316LN were investigated through optical microscopy,EDS,and EBSD techniques.The results indicated that the massive σ phase with brittle properties precipitated in the center layer of 316LN was the main cause of the relatively low impact energy observed in the experiment.According to calculations using Thermo-Calc software,the σ phase in the center layer precipitated from the δ ferrite following prolonged hot deformation and annealing at 700-950 ℃.However,the δ ferrite and σ phase could be eliminated through proper thermo-mechanical treatments,which would improve the impact properties at ultralow temperatures.
查看更多>>摘要：Some aspects of the robot application in the iron and steel industry were introduced.Even though many successful robot systems improved automation and human-machine operation in iron plants,based on the characteristics of the iron and steel industry,difficulties remain for robot applications that are different from other industries.Research and development for robot application is necessary to promote more robots that help personnel work.Furthermore,some key points,new applications,and technological innovation need to be focused on.
查看更多>>摘要：The application status of color difference formulas in coil coatings was investigated,with a focus on comparing the CIEDE2000 and HunterLab formulas.Experimental studies were conducted to evaluate the two formulas against the results of visual inspections.Findings indicate that the CIEDE2000 formula outperforms the HunterLab formula for most color variations.Therefore,the CIEDE2000 formula is suggested as an enhanced method for the quality control of color differences in coil coatings.
查看更多>>摘要：In this study,a comprehensive rolling mill vibration test program was designed,including specific test conditions and a test system.The analysis of measured signals reveals the vibration response characteristics and their evolution at different gauge points in the finishing mill.This is particularly evident during abnormal rolling,where the signals highlight the characteristics of abnormal responses and vibration intensities.Abnormal vibrations during the rolling process mainly occur when the strip thickness is less than 2.5 mm,and at the rolling speed-up stage,the strong abnormal vibration occurs at each measuring point on the F2 transmission side.The maximum vibration intensity of the backup roll's bearing seat is 17 mm/s.As the rolling progresses,the stress on the bolts changes.The strip thickness is negatively correlated with the peak values of bite and tail-flick impacts.The vibration characteristics vary with the strip thickness and the process state.
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