Burr Formation in Casting Using Vertical-Type High-Speed Twin-Roll Caster

2020 ◽  
Vol 846 ◽  
pp. 146-151
Author(s):  
Toshio Haga ◽  
Takuya Yamashiki ◽  
Hisaki Watari ◽  
Shinichi Nishida

The mechanism and region of burr formation in casting using a vertical-type high-speed twin-roll caster were investigated using a side-dam plate with a window. A383, an aluminum alloy typically used for casting due to its excellent fluidity at semisolid condition was used. The solid fraction of the semisolid metal ejected from the window was low. When solid metal was ejected from the window, no burr formed. The results suggest that a burr formed when the semisolid metal was ejected in gap between the side-dam plate and the side surface of a roll. The semisolid metal was ejected near the point where the semisolid metal on the two rolls met.

2020 ◽  
Vol 1007 ◽  
pp. 29-33
Author(s):  
Toshio Haga ◽  
Yushi Murakami ◽  
Shou Kitamura ◽  
Hisaki Watari ◽  
Shinichi Nishida

Strip casting using a side dam plate produces a vertical burr at the strip edge. In the present study, changing this vertical burr into a horizontal burr using a burr changer is proposed. The burr changer was placed inside the side dam plate. The burr changer was made from mild steel and an insulator sheet and cut along the shape of the roll. The burr changer was placed so as to prevent exhaustion of semisolid metal between the side dam plate and the roll-side surface. When the position of the burr changer was appropriate, the vertical burr changed into a horizontal burr. The horizontal burr was flat. The width of the horizontal burr was affected by the lowest position of the burr changer and became narrower as the lowest position of the burr changer approached the roll gap position.


2010 ◽  
Vol 139-141 ◽  
pp. 477-480
Author(s):  
Ryoji Nakamura ◽  
Shuya Hanada ◽  
Shinji Kumai ◽  
Hisaki Watari

An inline hot rolling was operated on 5182 aluminum alloy strip cast using a vertical type high speed caster (VHSTRC) at the speed of 60 m/min. A porosity existing at center line of the thickness and a ripple mark on the surface, these are typical defects of the strip cast by the VHSTRC, could be improved by the inline rolling. The rolling speed was as same as the roll-casting-speed of 60m/min. The temperature of the strip, when the inline rolling was operated, was 450oC. The reduction of the strip of the inline rolling was 35%.


2010 ◽  
Vol 154-155 ◽  
pp. 1544-1548 ◽  
Author(s):  
Kosuke Komeda ◽  
Ryoji Nakamura ◽  
Shinji Kumai

The disadvantages of the conventional twin-roll caster for aluminum alloy are low casting speeds and limited choices of alloys that are castable by this processing. It is known that strip casting of aluminum alloy 5182 is very difficult because of their wider freezing zones. The vertical-type high-speed twin-roll caster used in the present study was devised to overcome these disadvantages. Features of the high speed twin roll casters are as below. Mild steel rolls were used in order to increase the casting speed and to be made at a lower equipment cost. Roll coating is produced in casting of Al-Mg alloy. Therefore lubricant, that resists heat transfer, was not used in the present study. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated. The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metalography, a tension test, and a deep drawing test.


2013 ◽  
Vol 79 (804) ◽  
pp. 1156-1160
Author(s):  
Takuya YAMASHIKI ◽  
Toshio HAGA ◽  
Shinji KUMAI ◽  
Hisaki WATARI

2013 ◽  
Vol 79 (804) ◽  
pp. 1152-1155
Author(s):  
Takuya YAMASHIKI ◽  
Yuki SHIRAKAWA ◽  
Toshio HAGA ◽  
Shinji KUMAI ◽  
Hisaki WATARI

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 520
Author(s):  
Toshio Haga

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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