Investigation of the Influence of the Roll Surface on the Cast Strip at the Casting Using a Vertical Type High Speed Twin Roll Caster

A vertical type high speed twin roll caster can be cast an aluminum alloy strip directly from a melt at high casting speed. However defects of the cast strip occurred at faster roll speed, which includes small cracks on the cast strip and unsoundness thickness distribution. They are related to contact condition of roll surface and melt. In the present study, a grooved roll was used to eliminate the defects and adopted in terms of the cost saving. We experimented using several grooved rolls with different patterns. When the groove width was 0.45mm; depth 0.2mm; pitch 0.1mm and 1.0mm, stable casting was possible. The shape of bulge was formed on the cast strip surface by the grooved roll. As a result of color check, we found that the grooved roll eliminate the small cracks. We stopped the rotated roll during the casting to observe the contact condition between the melt and the roll, and confirmed how the bulge was formed. The as-cast strip with the bulge was able to cold rolling.

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Investigation of Burr on Strips Cast by Vertical-Type High-Speed Twin Roll Caster

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.831.40 ◽

2020 ◽

Vol 831 ◽

pp. 40-45 ◽

Cited By ~ 1

Author(s):

Toshio Haga ◽

Takuya Yamashiki ◽

Hisaki Watari ◽

Shinichi Niahida

Keyword(s):

High Speed ◽

Lower Edge ◽

Strip Surface ◽

Factors Affecting ◽

Twin Roll Caster ◽

Si Content ◽

Twin Roll ◽

Shape And Size

The factors affecting the shape and size of burrs that form at the edges of strips cast by a vertical type twin roll caster were investigated in this study. The size of the burr was found to be affected by the Si content of the strip. When the Si content was larger than 7 mass%, the burrs became larger. The position of the lower edge of the side dam plate also affected the shape of the burr. The burrs that formed were generally perpendicular to the strip surface but changed to being parallel to the strip surface as the position of the lower edge of the side dam plate was displaced upward from the center of the rolls.

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High Speed Roll Casting of Aluminum Alloy Strip

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.343 ◽

2005 ◽

Vol 475-479 ◽

pp. 343-348 ◽

Cited By ~ 5

Author(s):

Ryoji Nakamura ◽

Hisaki Watari ◽

Shinji Kumai

Keyword(s):

Mechanical Properties ◽

High Speed ◽

The Other ◽

Alloy Strip ◽

Cast Ingot ◽

Cast Strip ◽

Cooling Slope ◽

Roll Casting ◽

Twin Roll Caster ◽

Twin Roll

Two kinds of roll casters, which were suitable for high speed roll casting, were devised. One was a vertical type twin roll caster, and the other was an unequal diameter twin roll caster. The semisolid roll casting using a cooling slope was adopted to these roll casters. The solid fraction was smaller than 5%. 3 mm thickness of 6111 strip was cast at 60 m/min by the vertical type twin roll caster, and 5 mm thickness of 6111 strip was cast at 30 m/min by the unequal diameter twin roll caster. The microstructure of the as-cast strip was equiaxed and spherical, not columnar. The mechanical properties of the strip rolled from roll-cast strip were almost as same as that of the strip made from cast ingot.

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Roll Casting of Al-SiCp Strip

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.811 ◽

2011 ◽

Vol 675-677 ◽

pp. 811-814 ◽

Cited By ~ 1

Author(s):

Toshio Haga ◽

Teppei Nakamura ◽

S. Kumai ◽

H. Watari

Keyword(s):

Hot Rolling ◽

High Speed ◽

Strip Casting ◽

Cast Strip ◽

Fine Grain ◽

Roll Casting ◽

Speed Up ◽

Cold Rolled ◽

Twin Roll Caster ◽

Twin Roll

The strip casting of Al-SiCp alloy was operated by a high speed twin roll caster. The content of SiCp was 20Vol% and 30Vol%. Both of Al-20Vol%SiCp and Al-30Vol%SiCp strips could be cast continuously at the speed up to 90m/min. The SiCp particle distributed uniformly. This was the effect of fine grain of the strip. The as-cast strip of Al-20Vol%SiCp could be cold rolled after homogenization. The as-cast strip of Al-30Vol%SiCp could be cold rolled after once hot rolling and annealing. The as-cast strip of Al-20Vol%SiCp could be coiled at the diameter of 460mm.

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Reduction of Surface Cracks at Al-Mg Alloy Strip Surface Cast by Unequal Diameter Twin Roll Caster

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1007.6 ◽

2020 ◽

Vol 1007 ◽

pp. 6-11

Author(s):

Toshio Haga ◽

Kazuki Yamazaki ◽

Hisaki Watari ◽

Shinichi Nishida

Keyword(s):

Grain Size ◽

Molten Metal ◽

Previous Method ◽

Mg Alloy ◽

Surface Cracks ◽

Roll Surface ◽

Strip Surface ◽

Twin Roll Caster ◽

Heat Transfers ◽

Twin Roll

Al-Mg alloy strips were cast by an unequal-diameter twin-roll caster. It was found that cracks formed on the surface at grain boundaries. The grains near the surface were small in size, which likely contributed to crack formation. The use of a molten metal pouring method to increase the grain size near the surface is proposed to reduce cracks. In the previous method, molten metal is poured into a pool, which is on the lower roll surrounded by side-dam plates, a back-dam plate, and the upper roll. In this study, molten metal was directly poured onto the roll surface at a shallow angle using a launder. When the angle was smaller than 20°, cracks did not form. With the proposed method, the heat transfers between the molten metal and the roll surface decreased, as determined from the grain size and strip thickness. The cracks on the strip surface were color-checked and visually inspected.

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Effects of Nozzle and Roll on Surface Condition of Al-1%Si Strip Cast Using Vertical type High Speed Twin Roll Caster

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1042.53 ◽

2021 ◽

Vol 1042 ◽

pp. 53-59

Author(s):

Toshio Haga ◽

Tomoya Okada ◽

Shinichi Nishida ◽

Hisaki Watari

Keyword(s):

High Speed ◽

Crack Formation ◽

Surface Condition ◽

Clear Correlation ◽

Roll Surface ◽

Surface Cracking ◽

Strip Cast ◽

Twin Roll Caster ◽

Si Content ◽

Twin Roll

When a strip of Al-Si alloy with an Si content of 1% was cast using a vertical-type high-speed twin-roll caster, cracks form in its surface. The effects of the pouring method, the shape and position of the nozzle, and the roll surface texture on surface crack formation were evaluated with a roll caster. The rolls were made of a copper alloy, and the roll speed was 30 m/min. The as-cast strips were bent to investigate the degree of crack formation, and the outer surface of the strips was observed without magnification and with a stereomicroscope to determine the influence of the pouring method, the shape and position of the nozzle, and the roll surface. A roll machined to form V-shaped grooves 0.4 mm deep on the surface of the strips was most useful for reducing surface cracking. Changing the shape of the nozzle tip was second-most effective. There was a clear correlation between the roll surface condition and surface cracking in the Al-Si strip.

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Roll Casting of Al-SiCp Composite Strip

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.139-141.481 ◽

2010 ◽

Vol 139-141 ◽

pp. 481-484

Author(s):

Ryoji Nakamura ◽

Teppei Nakamura ◽

Ryoji Nakamura ◽

Hideto Harada ◽

Shinji Kumai ◽

...

Keyword(s):

Cold Rolling ◽

High Speed ◽

Alloy Strip ◽

Thickness Direction ◽

Composite Alloy ◽

Cast Strip ◽

Roll Casting ◽

Twin Roll Caster ◽

Twin Roll ◽

Steel Rolls

Roll casting of Al-SiCp composite alloy strip was tried using a vertical type high speed twin roll caster equipped with mild steel rolls. The Al-20vol% SiCp and Al-30vol%SiCp alloy could be roll-cast to the strip. The casting speed was 30m/min. The thickness of as-cast strip was thinner than 2.5mm. The SiCp powder was dispersed uniformly at the thickness direction. The as-cast strip could be thin down to 1mm by the hot rolling and the cold rolling without broken.

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Effect of Roll Surface on Aluminum Alloy Strip Fabricated by a High-Speed Twin Roll Caster

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.79.1156 ◽

2013 ◽

Vol 79 (804) ◽

pp. 1156-1160

Author(s):

Takuya YAMASHIKI ◽

Toshio HAGA ◽

Shinji KUMAI ◽

Hisaki WATARI

Keyword(s):

Aluminum Alloy ◽

High Speed ◽

Alloy Strip ◽

Roll Surface ◽

Twin Roll Caster ◽

Twin Roll

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High Speed Roll Caster for Aluminum Alloy

Metals ◽

10.3390/met11030520 ◽

2021 ◽

Vol 11 (3) ◽

pp. 520

Author(s):

Toshio Haga

Keyword(s):

Thermal Conductivity ◽

Aluminum Alloy ◽

Copper Alloy ◽

High Speed ◽

The Other ◽

Center Line ◽

Cast Strip ◽

Roll Casting ◽

Twin Roll Caster ◽

Twin Roll

Two types of high-speed twin-roll casters and a single-roll caster equipped with a scraper were proposed. One of the twin-roll casters is a vertical-type high-speed twin-roll caster, and the other twin-roll caster is an unequal-diameter twin-roll caster. The vertical-type high-speed twin-roll caster can cast strip at speeds of up to 120 m/min. The unequal-diameter twin-roll caster casts strip at speeds up to 60 m/min. The unequal-diameter twin-roll caster is superior to the vertical-type high-speed twin-roll caster at the point of conveyance of the cast strip. A single-roll caster equipped with a scraper can cast strip without center-line segregation at speeds of up to 40 m/min. The use of a copper alloy roll and the non-use of a parting material enable high-speed roll casting. Since the roll loads of these casters are smaller than 0.1 kN/mm, soft copper alloy roll can be used. The strip does not stick to the roll without the parting material because of the use of the copper alloy roll with high thermal conductivity and the small roll load. The cooling rate near the surface is higher than 2000 °C/s.

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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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