Bare Spot Defect on a Hot Dip Galvanized DP Sheet Strip

2018 ◽  
Vol 913 ◽  
pp. 294-303
Author(s):  
Qi Wei Wu ◽  
Ai Min Zhao ◽  
Shun Yao ◽  
Zhen Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Laser Scanning ◽  
Steel Strip ◽  
High Strength ◽  
Dew Point ◽  
Emission Spectrometry ◽  
Inhibition Layer ◽  
Strip Surface ◽  
Dp Steel ◽  
Bare Spot

Bare spots defect of galvanealed (GA) in High Strength Dual Phase (DP) steel strip with 1.5 % Mn contain was studied in detail. The surface morphologies of spot defects before and after partial and complete removal of the Zn layer, as well as the interface between the outermost coating layer and the sheet substrate were analyzed by optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray Photoelectron spectroscopy (XPS), glow discharge optical emission spectrometry (GDOES) and laser scanning confocal microscope(LSCM). It was found that the bare spots defect was composed of a large number of pits with different sizes and depths. There were a lot of Fe - Zn alloy particles distributed in the pits, and many MnO formed on the surface, no effective Fe2Al5 inhibition layer formed. The results showed that the main reasons for the bare spots defect of the GA in High Strength DP steel strip are as follows: a silicon oxide film forms on the substrate during annealing prior to hot dipping because of Mn gathered on the surface of steel strip, thus strip surface wettability with liquid zinc is deteriorated and preventing the formation of the Fe2Al5 inhibition layer during hot dipping. In this paper, the dew point control process is introduced creatively, by increasing the dew point and the hydrogen content in the furnace area, and the bare spot defects on the surface of the high strength duplex steel galvanized sheet are solved.

Effect of Copper and Annealing Dew Point on Oxidation Behavior of C-Si-Mn Steels

2018 ◽  
Vol 913 ◽  
pp. 286-293
Author(s):  
Guang Rui Jiang ◽  
Hai Quan Wang ◽  
Li Bin Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Behavior ◽  
Optical Emission ◽  
Sem Analysis ◽  
Dew Point ◽  
Emission Spectrometry ◽  
X Ray ◽  
External Oxidation ◽  
Effect Of Copper ◽  
Mn Steel

The effect of copper on oxidation behavior of a C-Si-Mn steel was investigated. The samples were heated to 820°C and held for 75s under four different dew points with 5vol% hydrogen. The results of glow discharge optical emission spectrometry (GDOES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis techniques revealed the differences in oxidation. It is proposed that the steel containing 0.3 wt.% copper has less external oxidation of silicon and manganese compared to the steel containing no copper for all different dew points. As researched in this paper the external oxidation of C-Si-Mn steels would be suppressed by adding copper.

scholarly journals X-SDD: A New Benchmark for Hot Rolled Steel Strip Surface Defects Detection

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 706
Author(s):  
Xinglong Feng ◽  
Xianwen Gao ◽  
Ling Luo
Keyword(s):  
Surface Defect ◽  
Surface Defects ◽  
Steel Strip ◽  
Rolled Strip ◽  
Rolled Steel ◽  
Strip Surface ◽  
Hot Rolled Strip ◽  
Hot Rolled ◽  
Hot Rolled Steel ◽  
Detection Of Defects

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.

scholarly journals Investigation of Spin Coating Cerium-Doped Hydroxyapatite Thin Films with Antifungal Properties

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 464
Author(s):  
Simona Liliana Iconaru ◽  
Mihai Valentin Predoi ◽  
Patrick Chapon ◽  
Sofia Gaiaschi ◽  
Krzysztof Rokosz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Spin Coating ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
X Ray ◽  
Antifungal Properties ◽  
Scanning Electron

In this study, the cerium-doped hydroxyapatite (Ca10−xCex(PO4)6(OH)2 with xCe = 0.1, 10Ce-HAp) coatings obtained by the spin coating method were presented for the first time. The stability of the 10Ce-HAp suspension particles used in the preparation of coatings was evaluated by ultrasonic studies, transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The surface morphology of the 10Ce-HAp coating was studied by SEM and atomic force microscopy (AFM) techniques. The obtained 10Ce-HAp coatings were uniform and without cracks or unevenness. Glow discharge optical emission spectroscopy (GDOES) and X-ray photoelectron spectroscopy (XPS) were used for the investigation of fine chemical depth profiling. The antifungal properties of the HAp and 10Ce-HAp suspensions and coatings were assessed using Candida albicans ATCC 10231 (C. albicans) fungal strain. The quantitative antifungal assays demonstrated that both 10Ce-HAp suspensions and coatings exhibited strong antifungal properties and that they successfully inhibited the development and adherence of C. albicans fungal cells for all the tested time intervals. The scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) visualization of the C. albicans fungal cells adherence to the 10Ce-HAp surface also demonstrated their strong inhibitory effects. In addition, the qualitative assays also suggested that the 10Ce-HAp coatings successfully stopped the biofilm formation.

Development of a YOLO-V3-based model for detecting defects on steel strip surface

Measurement ◽  
2021 ◽  
pp. 109454
Author(s):  
Xupeng Kou ◽  
Shuaijun Liu ◽  
Kaiqiang Cheng ◽  
Ye Qian
Keyword(s):  
Steel Strip ◽  
Strip Surface

scholarly journals Enhanced Water Resistance of Recycled Newspaper/High Density Polyethylene Composite Laminates via Hydrophobic Modification of Newspaper Laminas

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 421
Author(s):  
Binwei Zheng ◽  
Weiwei Zhang ◽  
Litao Guan ◽  
Jin Gu ◽  
Dengyun Tu ◽  
...  
Keyword(s):  
Stearic Acid ◽  
Photoelectron Spectroscopy ◽  
Composite Laminates ◽  
High Density Polyethylene ◽  
Water Resistance ◽  
Laminated Composite ◽  
High Strength ◽  
High Water ◽  
High Density ◽  
X Ray

A high strength recycled newspaper (NP)/high density polyethylene (HDPE) laminated composite was developed using NP laminas as reinforcement and HDPE film as matrix. Herein, NP fiber was modified with stearic acid (SA) to enhance the water resistance of the NP laminas and NP/HDPE composite. The effects of heat treatment and SA concentration on the water resistance and tensile property of NP and composite samples were investigated. The chemical structure of the NP was characterized with X-ray diffractometer, X-ray photoelectron spectroscopy and attenuated total reflectance Fourier transform infrared spectra techniques. The surface and microstructure of the NP sheets were observed by scanning electron microscopy. An expected high-water resistance of NP sheets was achieved due to a chemical bonding that low surface energy SA were grafted onto the modified NP fibers. Results showed that the hydrophobicity of NP increased with increasing the stearic acid concentration. The water resistance of the composite laminates was depended on the hydrophobicity of the NP sheets. The lowest value of 2 h water absorption rate (3.3% ± 0.3%) and thickness swelling rate (2.2% ± 0.4%) of composite were obtained when the SA concentration was 0.15 M. In addition, the introduction of SA can not only enhance the water resistance of the composite laminates, but also reduce the loss of tensile strength in wet conditions, which shows potential in outdoor applications.

The Microstructure and Formability Study on DP Steel of Lightweight Automobile

2011 ◽  
Vol 704-705 ◽  
pp. 1465-1472
Author(s):  
Jin Wu ◽  
Da Sen Bi ◽  
Liang Chu ◽  
Jian Zhang ◽  
Yun Tao Li
Keyword(s):  
Mechanical Property ◽  
Work Hardening ◽  
High Strength Steel ◽  
High Strength ◽  
Mathematic Model ◽  
Theoretical Research ◽  
Forming Limit ◽  
Strain Hardening Exponent ◽  
Dp Steel ◽  
Better Than

Dual phase (DP) steel is a high strength steel for auto-panel. In this paper, mechanical property, forming ability, baked-hardening and work hardening properties of high strength steel DP450 are studied by experiments, and compared with those of steel MS6000.And theoretical research on predicting the forming limit of steel DP450 by the NADDRG model. The established mathematic model for relativity is of practical usefulness. Experimental results reveal that the yield strength of steel DP450 is about 7.2% lower than the MS6000,and the break strength increases by 18.9%,while the elongation increases by 19%.The strain hardening exponent of steel DP450 are superior to those of MS6000.The results show that mechanical property of high strength steel DP450 is better than that of MS6000,while forming ability of DP450 is not lower than that of MS6000.And baked-hardening and work hardening properties of steel DP450 are better than those of MS6000.The steel sheet DP450 owned a good forming ability.

scholarly journals Analysis of Roll Gap Heat Transfers in Hot Steel Strip Rolling through Roll Temperature Sensors and Heat Transfer Models

2012 ◽  
Vol 504-506 ◽  
pp. 1043-1048 ◽  
Author(s):  
Nicolas Legrand ◽  
Nathalie Labbe ◽  
Daniel Weisz-Patrault ◽  
Alain Ehrlacher ◽  
Tomasz Luks ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Steel Strip ◽  
Temperature Sensors ◽  
Strip Rolling ◽  
Strip Surface ◽  
Roll Temperature ◽  
Heat Transfers ◽  
Roll Gap ◽  
Roll Bite ◽  
Transfer Models

This paper presents an analysis of roll bite heat transfers during hot steel strip rolling. Two types of temperature sensors (drilled sensor /slot sensor) implemented near roll surface and heat transfer models are used to identify in the roll bite interfacial heat flux, temperature and Heat Transfer Coefficient HTCroll-bite during pilot rolling tests. It is shown that: - the slot type sensor is much more efficient than the drilled type sensor to capture correctly fast roll temperature changes in the bite during hot rolling but life’s duration of the slot sensor is shorter. - average HTCroll-bite, identified with roll sensors temperature signals is within the range 15-26 kW/m2/K: the higher the strip reduction is, the higher the HTCroll-bite is. - scale thickness at strip surface tends to decrease heat transfers from strip to roll in the roll bite. - HTCroll-bite appears not uniform along the roll-strip contact, in contrast to usual assumptions made in existing models - Heat dissipated by friction at roll-strip interface and its partitioning through roll and strip respectively seems over-estimated in the existing thermal roll gap model [1]. Modeling of interfacial friction heat dissipation should be reviewed and verified. The above results show the interest of roll temperature sensors to determine accurately roll bite heat transfers and evaluate more precisely the corresponding roll thermal fatigue degradation.

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