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

2020 ◽  
Vol 831 ◽  
pp. 40-45 ◽  
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.

Roll Casting and Die Casting of Si-Added Al-Mg Alloy

2020 ◽  
Vol 1007 ◽  
pp. 12-17
Author(s):  
Toshio Haga ◽  
Shinichiro Imamura ◽  
Hiroshi Fuse ◽  
Hisaki Watari ◽  
Shinichi Nishida
Keyword(s):  
High Speed ◽  
Die Casting ◽  
Sheet Forming ◽  
Mg Alloy ◽  
Tension Tests ◽  
Roll Casting ◽  
Cold Rolled ◽  
Twin Roll Caster ◽  
Si Content ◽  
Twin Roll

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.

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

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.

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

2012 ◽  
Vol 184-185 ◽  
pp. 271-276
Author(s):  
Takuya Yamashiki ◽  
T. Haga ◽  
S. Kumai ◽  
H. Watari
Keyword(s):  
High Speed ◽  
Thickness Distribution ◽  
Contact Condition ◽  
Roll Surface ◽  
Strip Surface ◽  
Cast Strip ◽  
Small Cracks ◽  
Twin Roll Caster ◽  
The Cost ◽  
Twin Roll

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.

Effect of Si on AA5182 Strip Cast by a High Speed Twin Roll Caster

2012 ◽  
Vol 184-185 ◽  
pp. 834-837 ◽  
Author(s):  
Toshio Haga ◽  
Kosuke Komeda ◽  
Kenta Mtsuoka ◽  
Shinji Kumai ◽  
Hisaki Watari
Keyword(s):  
High Speed ◽  
Tension Test ◽  
Thickness Direction ◽  
Roll Casting ◽  
Strip Cast ◽  
Twin Roll Caster ◽  
Si Content ◽  
Twin Roll ◽  
Steel Rolls ◽  
Center Area

High speed roll casting of AA5182 aluminum alloy was tried using a vertical type high speed twin roll caster equipped with mild-steel rolls. Parting material was not used and speed was 80m/min. AA5182 strip, which thickness was 2.1mm, could be cast continuously. However, porosity occurred at center area at the thickness direction of the strip of the as-cast strip. Si was added to original AA5182 to improve the porosity at 0.2, 0.4, 0.6, 0.8 and 1.0 mass%. The porosity was improved as the content of the Si increased. The elongation resulting from the tension test was the best when 0.2mass%Si was added. The clack on the surface was improved by the increase of the Si content. Roll casting ability was improved by the Si, too.

Inline Rolling of 5182 Aluminum Alloy Strip Cast by a Vertical Type High Speed Twin Roll Caster

2010 ◽  
Vol 139-141 ◽  
pp. 477-480
Author(s):  
Ryoji Nakamura ◽  
Shuya Hanada ◽  
Shinji Kumai ◽  
Hisaki Watari
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Rolling Speed ◽  
Center Line ◽  
Alloy Strip ◽  
Ripple Mark ◽  
Roll Casting ◽  
Strip Cast ◽  
Twin Roll Caster ◽  
Twin Roll

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%.

Roll Casting of Al-40%Sn-1%Cu Strip

2018 ◽  
Vol 382 ◽  
pp. 147-154
Author(s):  
Toshio Haga ◽  
Ryusuke Onishi ◽  
Hisaki Watari ◽  
Shinichi Nishida
Keyword(s):  
Aluminum Alloy ◽  
Molten Metal ◽  
Solidification Time ◽  
Roll Speed ◽  
Strip Surface ◽  
Sliding Bearings ◽  
Roll Casting ◽  
Twin Roll Caster ◽  
Metal Microstructure ◽  
Twin Roll

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.

Changing from a Vertical Burr to a Horizontal Burr in the Vertical-Type High-Speed Twin-Roll Caster

2020 ◽  
Vol 1007 ◽  
pp. 29-33
Author(s):  
Toshio Haga ◽  
Yushi Murakami ◽  
Shou Kitamura ◽  
Hisaki Watari ◽  
Shinichi Nishida
Keyword(s):  
Mild Steel ◽  
High Speed ◽  
Side Surface ◽  
Strip Casting ◽  
Strip Edge ◽  
Twin Roll Caster ◽  
Roll Gap ◽  
Twin Roll ◽  
Semisolid Metal

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.

High Speed Twin-Roll Casting of Al-Mg Alloys

2010 ◽  
Vol 154-155 ◽  
pp. 1544-1548 ◽  
Author(s):  
Kosuke Komeda ◽  
Ryoji Nakamura ◽  
Shinji Kumai
Keyword(s):  
Heat Transfer ◽  
Aluminum Alloy ◽  
High Speed ◽  
Aluminum Alloy 5182 ◽  
Roll Casting ◽  
Twin Roll Caster ◽  
Deep Drawing Test ◽  
Study Heat Transfer ◽  
Twin Roll ◽  
Steel Rolls

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.

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