120x2000 Single Strand Continuous Slab Casting Machine 1.5 m/min
Molten metal is tapped into the ladle from furnaces. After
undergoing any ladle treatments, such as alloying and degassing,
and arriving at the correct temperature, the ladle is transported
to the top of the casting machine. Usually the ladle sits in a slot
on a rotating turret at the casting machine. One ladle is in the
'on-cast' position (feeding the casting machine) while the other is
made ready in the 'off-cast' position, and is switched to the
casting position when the first ladle is empty.
From the ladle, the hot metal is transferred via a refractory shroud (pipe) to a holding bath called a tundish. The tundish allows a reservoir of metal to feed the casting
machine while ladles are switched, thus acting as a buffer of hot
metal, as well as smoothing out flow, regulating metal feed to the
molds and cleaning the metal (see below).
Metal is drained from the tundish through another shroud into the
top of an open-base copper mold. The depth of the mold can range from 0.5 to 2 metres (20 to 79
in), depending on the casting speed and section size. The mold is
water-cooled to solidify the hot metal directly in contact with it;
this is the primary cooling process. It also oscillates vertically (or in a near vertical
curved path) to prevent the metal sticking to the mold walls. A
lubricant can also be added to the metal in the mold to prevent
sticking, and to trap any slag particles—including oxide particles
or scale—that may be present in the metal and bring them to the top
of the pool to form a floating layer of slag. Often, the shroud is
set so the hot metal exits it below the surface of the slag layer
in the mold and is thus called a submerged entry nozzle (SEN). In
some cases, shrouds may not be used between tundish and mold; in
this case, interchangeable metering nozzles in the base of the
tundish direct the metal into the moulds. Some continuous casting
layouts feed several molds from the same tundish.
In the mold, a thin shell of metal next to the mold walls
solidifies before the middle section, now called a strand, exits
the base of the mold into a spray chamber. The bulk of metal within
the walls of the strand is still molten. The strand is immediately
supported by closely spaced, water-cooled rollers which support the
walls of the strand against the ferrostatic pressure (compare hydrostatic pressure) of the still-solidifying liquid within the strand. To increase
the rate of solidification, the strand is sprayed with large
amounts of water as it passes through the spray-chamber; this is
thesecondary cooling process. Final solidification of the strand may take place after
the strand has exited the spray-chamber.
It is here that the design of continuous casting machines may vary.
This describes a 'curved apron' casting machine; vertical
configurations are also used. In a curved apron casting machine,
the strand exits the mold vertically (or on a near vertical curved
path) and as it travels through the spray-chamber, the rollers
gradually curve the strand towards the horizontal. In a vertical
casting machine, the strand stays vertical as it passes through the
spray-chamber. Molds in a curved apron casting machine can be
straight or curved, depending on the basic design of the machine.
In a true horizontal casting machine, the mold axis is horizontal
and the flow of steel is horizontal from liquid to thin shell to
solid (no bending). In this type of machine, either strand or mold
oscillation is used to prevent sticking in the mold.
After exiting the spray-chamber, the strand passes through
straightening rolls (if cast on other than a vertical machine) and
withdrawal rolls. There may be ahot rolling stand after withdrawal to take advantage of the metal's hot
condition to pre-shape the final strand. Finally, the strand is cut
into predetermined lengths by mechanical shears or by travelling
oxyacetylene torches, is marked for identification, and is taken
either to a stockpile or to the next forming process.
In many cases the strand may continue through additional rollers
and other mechanisms which may flatten, roll or extrude the metal
into its final shape.
Wuxi Bolong Machinery Co.,Ltd is an integrated professional
metallurgy machinery manufacturer, capable of providing Equipment
Design, Manufacture, Installation, and Commissioning. Our factory
is competent to produce all kinds of continuous casting machine
with radius from 3 meters to 13 meters, such as round billet,
square billets and slabs.
Welcome to visit and inspect!
Contact persone: Angel Zhang