Casting of Clad Strip by an Unequal Diameter Twin Roll Caster

2010 ◽  
Vol 638-642 ◽  
pp. 413-418 ◽  
Author(s):  
Ryoji Nakamura ◽  
Masakazu Sawai ◽  
Ryoji Nakamura ◽  
H. Watari ◽  
S. Kumai

An unequal diameter twin roll caster which can cast clad strips was devised and assembled. The casting of the clad strip was tried, and fabrication of the clad strip was attained. This twin roll caster was planned for the process saving. The clad strip was assembled directly from AA3003 molten metal and AA4045 molten metal at speed of 20m/min. The Si-diffusion-area between the strips was very narrow, and the interface between the strips was clear. The strips were bonded firmly. The strips were not pealed by the cold rolling and the continuous bending.

2010 ◽  
Vol 443 ◽  
pp. 128-133 ◽  
Author(s):  
Ryoji Nakamura ◽  
Masakazu Sawai ◽  
Ryoji Nakamura ◽  
Takanori Yamabayashi ◽  
Shinji Kumai ◽  
...  

A roll caster, which could cast the three layers of clad strip directly from the molten metal, was designed, assembled and tested. The base strip was AA3003 aluminum alloy and overlay strips were AA4045 aluminum alloy. An unequal diameter twin roll caster was modified to cast clad strip. Two small rolls were amounted on a large roll. A scraper plate was used to prevent the mixture of the different kinds of melts. The casting of three strips and the connecting of strips could be operated by one roll caster. The interfaces between the strips were clear, and the mixture of the melt did not occur. The clad strip could be cold rolled without the annealing. The clad strip did not peel at connecting surface by the cold rolling and continuous bending. The strips were connected strictly. The casting speed was 20m/min, and this speed was much higher than the casting speed of the conventional twin roll caster for aluminum alloys.


2018 ◽  
Vol 382 ◽  
pp. 147-154
Author(s):  
Toshio Haga ◽  
Ryusuke Onishi ◽  
Hisaki Watari ◽  
Shinichi Nishida

Strip casting of Al-40%Sn-1%Cu, which is an aluminum alloy used for sliding bearings, was attempted using an unequal diameter twin roll caster. The conditions required to cast sound strips, including the roll speed, molten temperature, roll load, solidification length, melt head, and use of an upper plate, were investigated. The roll load required to make a stable strip surface was 0.01 kN/mm, and the porosity was minimum when the solidification time was less than 0.6 s. The solidification time was controlled by the roll speed and the solidification length. The casting temperature must be set below 670°C to properly solidify the molten metal, and the metal microstructure became finer as the melt head decreased.


2011 ◽  
Vol 189-193 ◽  
pp. 4037-4040
Author(s):  
Ryoji Nakamura ◽  
Toshio Haga ◽  
H. Tsuge ◽  
S. Kumai ◽  
H. Watari

The three layers clad strip was fabricated by a vertical type tandem twin roll caster for clad strip (VTTCC). The effect of the casting conditions of the base strip and the overlay strip on the interface between the base strip and the overlay strip was investigated. The temperature of the molten metal and roll-load were investigated casting conditions. Base strip was AA8079 and overlay strip was AA6022. The proper melt temperature of the overlay strip was around the liquidus line of the base strip. The proper roll-load, which was smaller than rolling, was existed.


2020 ◽  
Vol 326 ◽  
pp. 06003
Author(s):  
Toshio Haga

An Al-Mg strip without center segregation could be cast using a single-roll caster equipped with a scraper at speed of 40 m/min. The scraper was useful for flattening a free solidified surface and for cooling the solidification layer by pushing the solidification layer to the roll. Clad strips consisting of 1) an Al-Mn base strip and an Al-Mg overlay strip and 2) an Al base strip and an Al-Sn-Cu overlay strip could be cast using an unequal-diameter twin-roll caster equipped with a scraper at speeds of 30 m/min and 15 m/min, respectively. The base strip and overlay strip were strongly bonded at the interface between the base strip and the overlay strip. The elements of the overlay strip did not diffuse into the base strip. The scraper played two roles in the casting of the clad strip: prevention of the mixture of two kinds of molten metal and making the surface of the base strip a semisolid of high solid fraction.


2020 ◽  
Vol 1007 ◽  
pp. 6-11
Author(s):  
Toshio Haga ◽  
Kazuki Yamazaki ◽  
Hisaki Watari ◽  
Shinichi Nishida

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.


2018 ◽  
Vol 792 ◽  
pp. 8-15
Author(s):  
Toshio Haga ◽  
Kentaro Okamura ◽  
Hisaki Warari ◽  
Shinichi Nishida

The effect of the base strip temperature on the bonding between base strip and overlay strips in a three-layer clad strip cast by a vertical-type tandem twin roll caster was investigated. The base strip was 3003 aluminum alloy and the overlay strip was 4045 aluminum alloy. The bonding was investigated for base strip temperatures ranging from 200 °C to 550 °C. The bonding condition was investigated by cold-rolling, bending-to-failure test and tensile shear test. The shear stress increased with the base strip temperature. Sound bonding was achieved at base strip temperatures higher than 450 °C. The results of this study indicated that the second caster is not required to be set below the first roll caster.


2010 ◽  
Vol 139-141 ◽  
pp. 481-484
Author(s):  
Ryoji Nakamura ◽  
Teppei Nakamura ◽  
Ryoji Nakamura ◽  
Hideto Harada ◽  
Shinji Kumai ◽  
...  

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.


2017 ◽  
Vol 748 ◽  
pp. 181-186
Author(s):  
Toshio Haga ◽  
Shinichi Nishida ◽  
Hisaki Watari

An unequal diameter twin-roll caster equipped with a channel scraper is proposed to improve center-line segregation. A semisolid metal layer was made by the channel scraper on the upper side of the strip and solidified by an upper roll. The twin-roll caster cast a strip of 5182 with equiaxed grain and without center-line segregation at a speed of 30 m/min and a unit roll load of 104 N/mm. The tensile stress and elongation after cold rolling and annealing were 294 MPa and 28%, respectively.


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%.


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