Influence of the cross section of hot-rolled steel on the flatness of cold-rolled strip

2013 ◽  
Vol 43 (5) ◽  
pp. 313-316 ◽  
Author(s):  
S. M. Bel’skii ◽  
Yu. A. Mukhin ◽  
S. I. Mazur ◽  
A. I. Goncharov
Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 706
Author(s):  
Xinglong Feng ◽  
Xianwen Gao ◽  
Ling Luo

It is important to accurately classify the defects in hot rolled steel strip since the detection of defects in hot rolled steel strip is closely related to the quality of the final product. The lack of actual hot-rolled strip defect data sets currently limits further research on the classification of hot-rolled strip defects to some extent. In real production, the convolutional neural network (CNN)-based algorithm has some difficulties, for example, the algorithm is not particularly accurate in classifying some uncommon defects. Therefore, further research is needed on how to apply deep learning to the actual detection of defects on the surface of hot rolled steel strip. In this paper, we proposed a hot rolled steel strip defect dataset called Xsteel surface defect dataset (X-SDD) which contains seven typical types of hot rolled strip defects with a total of 1360 defect images. Compared with the six defect types of the commonly used NEU surface defect database (NEU-CLS), our proposed X-SDD contains more types. Then, we adopt the newly proposed RepVGG algorithm and combine it with the spatial attention (SA) mechanism to verify the effect on the X-SDD. Finally, we apply multiple algorithms to test on our proposed X-SDD to provide the corresponding benchmarks. The test results show that our algorithm achieves an accuracy of 95.10% on the testset, which exceeds other comparable algorithms by a large margin. Meanwhile, our algorithm achieves the best results in Macro-Precision, Macro-Recall and Macro-F1-score metrics.


2020 ◽  
pp. 33-37
Author(s):  
S. M. Belskiy ◽  
◽  
A. N. Shkarin ◽  
V. A. Pimenov ◽  
◽  
...  

The geometric parameters describing the features of the crosssectional profile of a hot-rolled strips do not give a complete picture of the flatness acquired by the cold-rolled strips rolled from these strips. An additional analysis, the results of which are presented in Message 1, showed that there are four characteristic classes of cross-sectional profiles of hot rolled strips that have a significant effect on the shape of the strips during cold rolling, three of which negatively affect the flatness of the cold rolled strips. The cross-sectional profiles of hot-rolled strips with a concave middle part and / or marginal thickenings lead to the appearance of edge waviness, peak-like cross-sectional profiles cause central warping. Therefore, the actual task is to determine the factual shape of cross-sectional profile. 6th order polynomials were used to digitalize and parameterize hot-rolled profile. As a result, we developed analytic function of the transverse profile, which keeps important information about its near-edge areas and features in the middle part. To assign a specific crosssectional profile of a hot-rolled strip to one of four characteristic classes of cross-sections, mathematical software was developed, called a classifier, and implemented with the programming environment R. To classify the profiles of the hot-rolled cross-section according to characteristic classes, a linear discriminant method was used as a machine learning method analysis. The result is an adequate mathematical model for recognizing the shape of the cross-sectional profile. The study was carried out with the financial support of the Russian Foundation for Basic Research within the framework of scientific project No. 19-38-90257.


2021 ◽  
Vol 44 ◽  
pp. 2985-2992
Author(s):  
Merbin John ◽  
P. Ashok Kumar ◽  
K. Udaya Bhat ◽  
P. Devadas Bhat

2020 ◽  
Vol 63 (10) ◽  
pp. 808-814
Author(s):  
K. A. Kotov ◽  
N. L. Bolobanova ◽  
D. V. Nushtaev

The final stage in the production of hot rolled steel is leveling on roller levellers under cyclic alternating deformation. When laser is cutting a sheet it may bend due to the release of residual stresses that are unevenly distributed over the volume. The majority of roller leveller models for calculating the process under cyclic alternating deformation does not provide an adequate assessment and prediction of residual stresses in a steel sheet. On the basis of finite element analysis, formation of residual stresses owing to roller levelling of hot rolled strip is disclosed. The implementation of a model of the levelling process was performed in SIMULIA Abaqus. Models are verificated by comparing forces under the rollers. We have experimentally confirmed the convergence of the simulation results with the measurements of the strip flatness obtained after sheets plasma cutting. It was found that after levelling, tensile longitudinal residual stresses remain on the upper surface of the sheet, compressive ones remain on the lower surface, stresses are zero in the middle in thickness, and the stress values are opposite in sign in the remaining parts of the section. It was established that the same parameters of the levelling process of different strength categories lead to different deviations of stresses. An increase in yield strength of the strip leads to an increase in the deviation of residual stresses along the strip thickness. The proposed method of simulation of roller levelling process should be used to study the stress-strain state of hot-rolled steel and to design improved strip levelling setting modes with minimal residual stress deviations.


2011 ◽  
Vol 337 ◽  
pp. 242-246
Author(s):  
Xiang Yu Lv ◽  
Sheng Li Li ◽  
Na Li ◽  
Yong Hong Cai

The paper starts with a brief overview to the material used in auto panels , then leads to HRS Substituting CRS that SPHE hot-rolled steel substitutes ST13 cold-rolled steel in auto inner parts production. Through the composition of material chemical and performance parameters, simulation and stamping, the feasibility of HRS Substituting CRS is verified by Numerical simulation and field test.


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