The coiling of a steel strip in a Downcoiler is an integrated part of the hot-rolled steel production line. Failure to coiling results damage to finished rolled strip along with mill downtime due to ...cobble. Thus, coiling success in Downcoiler is a critical concern for production of hot rolled steel strip. A mathematical model has been developed to analyze coiling feasibility for new grade of high strength steel to be rolled for the first time in the mill and to thereby identify a safe operating window for the coiling-process parameters. This has significant benefit in reducing the risk of coiling failure during plant trial and thus product development cycle time. The model is based on the estimation of coiler tension for a new grade with reference to mill-based physical data of coiling compactness as defined by a wrapper angle from known grades, coiled in the mill. This is followed by computation and comparison of coiling torque vis-à-vis the capacity of the Downcoiler allows a decision to be taken about the coiling feasibility of the new grade. It is believed that it is for the first time that a coiling feasibility algorithm has been developed and discussed. The model has been widely used within Tata Steel to carry out plant trails for the development of new grade as well as rolling of new section in existing grades at its Hot Strip Mill in Indian plant at Kalinganagar.
The wide-width titanium strip cold rolling, as an efficient titanium material processing technology, has been widely concerned. During the cold rolling process, high-order flatness defects occur ...frequently, seriously restricting the improvement of titanium product quality. To analyze the mechanical deformation behavior of titanium strips during cold rolling, and explore the influence of entrance and exit profile index on the generation of high-order flatness defects. An integrated coupling rolling model of the roll system and the strip has been established based on the FEM method, and the accuracy of the model has been verified using on-site measured data. The research results show that when the taper or coning amount of the first intermediate roll increases, if the entrance profile index remains unchanged, the exit profile index will significantly decrease, and the high-order deflection deformation of the work roll axis will occur, ultimately leading to high-order flatness defects. When using the first intermediate taper roll to control the exit profile index, if the exit profile index remains unchanged, the entrance profile index increases by 10 μm, and the coning amount will increase by 8.3mm. Therefore, a plan based on the optimization of the entrance profile index has been proposed, which takes into account both the profile and the high-order flatness, to achieve a smaller coning amount to meet the exit profile index and decrease the risk of high-order flatness. The industrial test results show that after the implementation of the plan, the occurrence rate of high-order flatness decreased by an average of 34.42%.
Feeding strip into continuous casting mold is a technique that can reduce the central segregation and increase the equiaxed zone ratio of continuous casting slab. Over the past decades, some steel ...mills have gradually applied this technique, but it still lacks a comprehensive understanding of the control theory of process parameters. Many parameters joint the influence of the steel strip melting process and strip feeding ratio, deciding the inner quality of the slab eventually. Herein, the mechanism and heat transfer of feeding strip technology are analyzed. Parameter sensitivity studies and feeding strip experiments are summarized and some new conclusions are proposed. Finally, some suggestions for industrial production will give an outlook for future work.
For the first time, herein, the status of feeding strip technology (FST) in the continuous casting process is reviewed. Strip melting process, parameter sensitivity study, and FST experimental research are reviewed and discussed. Combined with thermal analysis, the complex relationship of feeding parameters is analyzed. Finally, some suggestions for industrial production give an outlook for future work.
•A dual electrochemical channel-based biosensor has been developed.•The dual channel Sensor can simultaneously measure the glucose and ketone with only one blood drop.•The dual channel sensor has the ...acceptable accuracy as compared to the clinical biochemical analyzer.•It paved the way for clinical point of care identification of diabetic ketoacidosis.
The traditional design of enzymatic test strip has single electrochemicalreaction, which can only measure one single biochemical parameter. We present one disposable electrochemical test strip with dual enzymatic reaction channel which is capable of simultaneously measuring glucose and blood ketone by one fingertip whole blood drop for clinical identification of diabetic ketosis (DK) and diabetic ketoacidosis (DKA). The blood glucose was measured in the 1st channel while blood ketone was measured in the 2th channel. The proposed test strip fulfils the rigid demand for diabetic patients with DK/DKA without double pricking the finger to determine the blood glucose and blood ketone, respectively. The results of clinical identification of diabetic ketoacidosis by the proposed test strip was verified by the clinical test with good consistency. The proposed test strip provides a cost effective and fast solution for clinical point of care identification of diabetic ketoacidosis.
The strip shape inheritance model is widely applied to improve the strip shape quality in tandem cold rolling (TCR). However, the inheritance mechanism is still currently unclear. To bridge this gap, ...this paper presents a new numerical method for calculating the strip crown inheritance factor. In addition, the effects of the entry strip crown on exit strip crown and flatness were quantitatively analysed at each stand in the TCR using a novel three-dimensional (3D) multi-stand elastic–plastic finite element (FE) model. The results show that the strip crown inheritance factor increases slowly from S1 (stand 1) to S3 (stand 3), while rising sharply from S3 to S5 (stand 5), reaching a peak value of 0.495 μm/μm at S5. This trend coincides with that of strip plastic rigidity, which verifies that the strip crown inheritance factor is dependent on the strip plastic rigidity. Furthermore, the variation of strip crown and flatness under different entry strip crowns from S1 to S5 is jointly influenced by the pass reduction and strip plastic rigidity. Moreover, the strip crown inheritance factor increases with the deformation resistance of the strip at both S1 and S5. These findings not only offer a fresh perspective to understand the mechanism of strip crown inheritance, but also provide an important basis for optimising the strip shape control in the TCR process.
In this paper, the effect of strip spacing on the aerodynamic performance of a high-speed pantograph with a double-strip is numerically studied using a shear stress transport turbulence model. Seven ...different strip spacings varied from 100 to 700 mm are considered. The errors in pantograph resistance between numerical simulation and wind tunnel test are within 5% in both knuckle-downstream and knuckle-upstream operating conditions. The drag and lift forces of the strip increase with the strip spacing when the train's running speed is 350 km/h. By considering the two strips individually, it is interesting to find that the lift force on the first strip tends to be stable as the spacing reaches up to 600 mm in both operating conditions, whereas the lift force on the second strip increases continuously with the spacing in the whole range of 100-700 mm. Furthermore, the aerodynamic coefficient of the strip is a nearly constant value at different running speeds, which increases with the strip spacing, suggesting that the relationship between the aerodynamic forces and the spacing of strips obtained in the current study can be extended to any speed level in the range of 200-350 km/h.
Feeding a cold steel strip into continuous casting (CC) mold is an effective method to improve the quality of large round bloom. However, it is difficult to assess the correlation between the bloom ...quality and the initial temperature of the strip. Therefore, a three‐phase mixed columnar–equiaxed solidification model is developed to evaluate the effect of feeding strip temperature on macrosegregation and solidification structure in a large vertical CC round bloom. The results show that feeding the steel strip induces “crystal rain” in the liquid core of the bloom and increases the volume fraction of the equiaxed phase. After feeding a strip, the flow direction of molten steel is changed, and the flow velocity is increased in the liquid core of the bloom. Furthermore, with initial temperature of the strip decreases, the production efficiency is improved. Compared to the four conditions investigated, the carbon distribution in the bloom is the most uniform, the negative segregation at the centerline of the bloom is the weakest with the value of −35.50%, and the extreme value difference of the macrosegregation index at 20 m below the meniscus is the smallest with the value of 38.35% under the condition of
T
initial
= 500 K.
To comprehensively understand the effect of oscillation on cooling capacity of steel strip, a mathematical model is proposed to investigate the distribution of temperature fields in continuous cast ...slabs, taking into account the oscillatory feeding process. Strip oscillation results in a periodic variation of nearby molten steel flow. It intensifies the turbulence of surrounding molten steel and enhances the interfacial heat transfer. During the feeding process, the morphology of strip undergoes three stages: upheaval, fluctuation, and disappearance. As the strip oscillation frequency increases, the maximum cross‐sectional area of the strip gradually decreases during the upheaval stage, the fluctuation stage gradually disappears, and the strip disappearance speed gradually increases during the disappearance stage. These observations suggest that an increase in the oscillation frequency accelerates the melting of the strip, which is caused by the enhanced heat transfer between the strip and molten steel. This results in a gradual growth of strip's cooling capacity and a decrement in the liquid fraction of molten steel surrounding the strip. In addition, feeding strip is advantageous in preventing the jet from impinging onto narrow surfaces of slab. The blocking effect initially increases and then remains almost unchanged as the strip oscillation frequency increases.
The cooling capacity of strip gradually increases with an increment in the oscillation frequency. As feeding strip oscillation frequency increases, the area of the low‐liquid‐fraction region gradually increases, which is beneficial in promoting central nucleation and grain growth during the actual production process.
Deoxynivalenol (DON) and zearalenone (ZEN) are mycotoxins that contaminate a wide range of grains and crops. In this study, a one-step time-resolved single-channel immunochromatographic test strip ...based on europium ion polystyrene fluorescence microspheres was first developed for sensitive and quantitative detection of DON and ZEN. The concentration of the artificial antigen and the mass ratio of the monoclonal antibody to fluorescent microspheres for conjugation were optimized to simplify the sample addition process during immunochromatographic assay and improve the on-site detection efficiency. The limits of detection (LOD) of the single-channel immunochromatographic test strip for DON and ZEN detection were 0.17 and 0.54 μg/L, respectively. Meanwhile, the dual-channel immunochromatographic test strip was designed to simultaneously detect DON and ZEN, with LODs of 0.24 and 0.69 μg/L achieved for DON and ZEN, respectively. The developed test strips also yielded recovery results consistent with that obtained by LC-MS/MS for DON and ZEN detection in real samples of wheat and corn flour, confirming the practicability and reliability of the test strip. The developed immunochromatographic test strips realize quick and sensitive detection of DON and ZEN, exhibiting potential for broad applications in the point-of-care testing platform of multiple mycotoxins in agricultural products.
Graphic abstract
•The defect detection samples of steel strip are complex and changeable.•Anchor-Free is used to detect targets with large scale difference.•The Dense structure provides a significant improvement in ...high resolution data.
During steel strip production, mechanical forces and environmental factors cause surface defects of the steel strip. Therefore, detection of such defects is key to the production of high quality products. Moreover, surface defects of the steel strip cause great economic losses to the high-tech industry. So far, few studies have explored methods of identifying the defects, and most of the currently available algorithms are not sufficiently effective. Therefore, we developed an end-to-end defect detection model based on YOLO-V3. Briefly, the anchor-free feature selection mechanism was utilized to select an ideal feature scale for model training, replace the anchor-based structure, and shorten the computing time. Next, specially designed dense convolution blocks were introduced into the model to extract rich feature information, which effectively improves feature reuse, feature propagation, and enhances the characterization ability of the network. The experimental results show that, compared with other comparison models, the improved model proposed in this study has higher performance. For instance, the proposed model yielded 71.3% mAP on the GC10-DET dataset, and 72.2% mAP on the NEU-DET dataset.
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