Improvement of Surface Roughness of Al-Si Alloy Cast Strip by Vertical Melt Drag Process

Strip casting process is possible to shorten for producing strip. Strip is produced from molten metal continuously and directly by strip casting process. Melt drag process is one of the single roll strip casting process. Melt drag process is simpler than general twin roll strip casting process. One of defect of cast strip is surface conditions, for example surface roughness. Cast strip surface roughness is larger than hot rolled strip. Large strip surface roughness is negative effect for cold rolling after strip casting or hot rolling. The aim of this study is improvement of cast strip surface roughness by melt drag process. We suggested vertical melt drag process. And investigations were operated such us producing conditions of Al-Si alloy strip, surface roughness of cast strip and microstructures.

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Investigation on Microstructure, Texture and Tensile Properties of Hot Rolled Strip Casting Grain-Oriented Silicon Steel

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.395-396.297 ◽

2013 ◽

Vol 395-396 ◽

pp. 297-301

Author(s):

Hong Yu Song ◽

Hui Hu Lu ◽

Hai Tao Liu ◽

Guo Dong Wang

Keyword(s):

Tensile Test ◽

Casting Process ◽

Fiber Texture ◽

Silicon Steel ◽

Strip Casting ◽

Rolled Strip ◽

Fracture Surface Morphology ◽

Cast Strip ◽

Hot Rolled ◽

Twin Roll

An Fe-3wt% Si as-cast strip was produced by twin-roll strip casting process. The as-cast strip was hot rolled at 1150°C by one pass of 20% reduction and coiled at 550°C. The tensile test was carried out and the elongation was measured. The microstructure and texture of the coiled strip and the fracture surface morphology of the tensile samples were characterized. It is found that the microstructure of the as-cast strip was characterized by columnar ferrite grains with pronounced {001}<0vw> fiber texture and martensite. The microstructure of coiled strip consisted of ferrite grains and pearlite, and the texture was mainly characterized by {001}<0vw> fiber texture. The necking was absent during the tensile test and the elongation of coiled strip was as low as 12%. The fracture surfaces of the tensile samples mainly exhibited cleavage fracture mode with coarse cleavage facets and some ligaments.

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Strip Casting of Al-25%Si Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.430-432.669 ◽

2012 ◽

Vol 430-432 ◽

pp. 669-672

Author(s):

Toshio Haga ◽

Hideto Harada ◽

Shinji Kumai ◽

Hisaki Watari

Keyword(s):

Strip Casting ◽

Rolled Strip ◽

Thickness Direction ◽

Cast Strip ◽

Primary Si ◽

Eutectic Si ◽

Cold Rolled ◽

Twin Roll Caster ◽

Hot Rolled ◽

Twin Roll

Strip casting of Al-25%Si strip was tried using an unequal diameter twin roll caster. The diameter of the lower roll (large roll) was 1000mm and the diameter of the upper roll (small roll) was 250mm. Roll material was mild steel. The sound strip could be cast at the speeds ranging from 8 m/min to 12 m/min. The strip did not stick to the roll without the parting material. The primary Si, which existed at centre area of the thickness direction, was larger than that which existed at other area. The size of the primary Si was smaller than 0.2 mm. Eutectic Si was smaller 5μm. The as-cast strip was ranging from 2mm to 3mm thick and its width was 100mm. The as-cast strip could be hot rolled down to 1mm. The hot rolled strip was cold rolled. The primary Si became smaller and the pore occurred around the primary Si after the rolling.

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Structure and Precipitation of Strip As-Cast and Hot-Rolled by TSCR on Oriented Silicon Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.506 ◽

2011 ◽

Vol 686 ◽

pp. 506-510

Author(s):

Yong Mei Yu ◽

Yun Bo Xu ◽

Yuan Xiang Zhang ◽

Ting Zhang ◽

Xiao Ming Zhang ◽

...

Keyword(s):

Silicon Steel ◽

Strip Casting ◽

Rolled Strip ◽

Texture Gradient ◽

Air Cooling ◽

Thin Slab Casting ◽

Hot Rolled Strip ◽

Slab Casting ◽

Hot Rolled ◽

Twin Roll

The simulation studies were carried out on the oriented silicon steel produced by thin slab casting and rolling (TSCR) and twin-roll strip casting in the laboratory. The precipitation of inhibiter, formation of microstructure and texture were investigated before cold rolling. The inhomogeneous microstructure and texture gradient were observed in the 7-pass hot-rolled strip（2mm）for TSCR process, and texture gradient was not changed after normalizing, and the twin-roll strip casting directly supplied a strip with approx 2mm of thickness being same as that of hot-rolled strip by TSCR. The microstructure of twin-rolling casting strip was almost composed of all equiaxed grains which similar to the normalizing microstructure in TSCR process, but the random texture was obtained by twin-rolling strip casting. The dispersed and clustered precipitates were presented in hot-rolled strip when the ingots were soaked at 1200°C and 1150°C respectively for the TSCR process. And disperse and acicular precipitates were observed by TEM for air-cooling cast strips for process twin-rolling casting.

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Effects of Rolling Condition on Warm Deep Drawability of Magnesium Alloy Sheets Produced by Twin-Roll Strip Casting

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.489 ◽

2005 ◽

Vol 475-479 ◽

pp. 489-492 ◽

Cited By ~ 3

Author(s):

Hisaki Watari ◽

Keith Davey ◽

M.T. Alonso Rasgado ◽

L.D. Clark ◽

Ryoji Nakamura ◽

...

Keyword(s):

Magnesium Alloy ◽

Magnesium Alloys ◽

Casting Process ◽

Strip Casting ◽

Drawing Ratio ◽

Deep Drawability ◽

Cast Magnesium Alloy ◽

Cast Magnesium ◽

Hot Rolled ◽

Twin Roll

Effects of rolling conditions on warm deep drawability of cast magnesium alloy that were hot rolled after roll strip casting were investigated to ascertain the feasibility of twin-roll strip casting process of AZ31B magnesium alloy. Hot rolling and heat treatment conditions were changed to examine which conditions were appropriate for producing AZ31B wrought magnesium alloys after strip casting process. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled.

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Casting of Al-25%Si Strip Using a Vertical Type Twin Roll Caster

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.1944 ◽

2011 ◽

Vol 239-242 ◽

pp. 1944-1947

Author(s):

Toshio Haga ◽

Hideto Harada ◽

Shinji Kumai ◽

Hisaki Watari

Keyword(s):

High Speed ◽

Strip Casting ◽

Cast Strip ◽

Roll Casting ◽

Twin Roll Caster ◽

Roll Gap ◽

Hot Rolled ◽

Semisolid Casting ◽

Twin Roll

Strip casting of Al-25%Si was tried using the vertical type high speed twin roll caster. Some devices were adopted to enable the strip casting of Al-25%Si. Control of the roll gap, semisolid casting and non-use of the lubricant were useful devices to cast Al-25%Si strip. Roll-casting-ability of the Al-25%Si was discussed. The strip could be cast at 20m/min and 40m/min. As-cast strip was hot rolled down to 1mm by one pass. Bulging was tried at 550°C and it was able.

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The Microstructure and Processing in Twin Roll Casting of Magnesium Alloy Strip

Materials Science Forum ◽

10.4028/www.scientific.net/msf.488-489.427 ◽

2005 ◽

Vol 488-489 ◽

pp. 427-430 ◽

Cited By ~ 15

Author(s):

Chun Mei Yang ◽

Ding Fei Zhang ◽

Pei Dao Ding ◽

Fu Sheng Pan

Keyword(s):

Magnesium Alloy ◽

Casting Process ◽

Strip Casting ◽

Casting Temperature ◽

Process Stability ◽

Cast Strip ◽

Twin Roll Casting ◽

Roll Casting ◽

Twin Roll ◽

Cast Microstructure

Magnesium has a hexagonal close-packed crystal structure which makes it more difficult to deform than aluminum. Conventional strip production usually requires several process steps to reach the final strip thickness. Strip casting can reduce some of the process steps and make strip processing simpler and easier, especially for alloys with poor deformability. The twin-roll casting process can directly obtain strips with thickness less than one or two millimeters. In this paper, the metallurgical characteristics of the twin-roll strip casting process were analyzed and discussed. A laboratory scale vertical twin roll caster in prepared AZ31 magnesium alloy strips, with 1.0 to 2.0 mm thick and 150mm wide. Process stability in the thin strip casting process of the alloy has been studied, the casting temperature (superheat) was proven to be a key factor influencing process stability and casting strip quality. The as-cast microstructure of the alloy was analyzed and evaluated by optical microscopy, which showed that the as-cast microstructure was composed of developed dendrites when the superheat was high, and of a rosebush-like structure when the superheat was low. When the casting temperature was close to the liquid phase temperature，the as-cast microstructure became global or grainy, and the grain size of the cast strip was very small. This remarkably improved the deformability of the as-cast strip.

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

Symmetry ◽

10.3390/sym13040706 ◽

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.

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