Study on high-speed twin-roll caster for aluminum alloys

2003 ◽  
Vol 143-144 ◽  
pp. 895-900 ◽  
Author(s):  
Toshio Haga ◽  
Shinsuke Suzuki
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%.


2021 ◽  
Vol 880 ◽  
pp. 17-22
Author(s):  
Geng Yan Feng ◽  
Hisaki Watari ◽  
Mayumi Suzuki ◽  
Toshio Haga ◽  
Toru Shimizu

This study introduces the direct cladding of magnesium and aluminum alloys using a horizontal twin roll caster in one step. A horizontal twin roll caster can cast a Mg/Al clad strip with thickness exceeding 5mm at a roll speed of 8m/min in one step, which is difficult for a vertical twin roll caster. Therefore, it is possible to cast a thick clad strip with different melting point alloys using a horizontal twin roll caster at low speed. It is also possible to cast clad strips using as the overlay an alloy that has a higher melting point than that of the base strips. The thickness of the Mg/Al clad strip is 6.5mm, and the ratio of the Mg layer to the Al layer is 3:2. The surface of the clad strip is good, and there is no void between bonding interfaces. The mixing layer of the bonding interface is deeply related to the reduction rate. As the reduction rate increases, the mixing layer becomes more balanced and the thickness of the mixed layer decreases to 68μm. By observation of the interface of the cladded material, the mixed layer of the bonding interface is divided into two layers. It has been found the mixed layer near the Al layer has the highest hardness (up to 228HV), and the tensile shearing strength of the manufactured Mg/Al clad strip was 44MPa.


2020 ◽  
Vol 831 ◽  
pp. 40-45 ◽  
Author(s):  
Toshio Haga ◽  
Takuya Yamashiki ◽  
Hisaki Watari ◽  
Shinichi Niahida

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.


2020 ◽  
Vol 1007 ◽  
pp. 12-17
Author(s):  
Toshio Haga ◽  
Shinichiro Imamura ◽  
Hiroshi Fuse ◽  
Hisaki Watari ◽  
Shinichi Nishida

Si ranging from 0.2 mass% to 2.0 mass% was added to Al-5%Mg alloy (5182) and strip was cast by a vertical type high-speed twin-roll caster at a speed of 80 m/min. The as-cast strip was cold-rolled down to 1 mm thickness and annealed. The mechanical properties were investigated using cup tests and tension tests. The limiting draw ratio (LDR) of the 5182 alloy was 2.0 and the LDR became smaller as the Si content increased. When the Si content was 2.0 mass%, the LDR was 1.8, which shows that Si-added 5182 can be used for sheet forming, if the Si content is less than 2.0 mass%. The tensile strength and elongation were almost constant when the Si content was less than 1 mass%, but decreased at 2.0 mass% Si. However, the elongation was greater than 20% at 2.0 mass% Si. For die casting, 2.0 mass% Si was determined as the appropriate content from the results of the tension tests. When the Si content is in the range from 1.0 mass% to 2.0 mass%, then the Si added Al-5%Mg has the ability to be used for both die casting and sheet forming.


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 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.


2005 ◽  
Vol 475-479 ◽  
pp. 343-348 ◽  
Author(s):  
Ryoji Nakamura ◽  
Hisaki Watari ◽  
Shinji Kumai

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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