[0001] This invention concerns a protective cover for the head of a starter bar in continuous
casting and also concerns a starter bar which employs such protective cover in continuous
casting.
[0002] To be more exact, the invention concerns an element which safeguards the inside of
a continuous casting ingot mould during the initial step of introducing and positioning
the starter bar.
[0003] It is known that an ingot mould to cool metal in continuous casting consists of an
alloy very expensive as regards the components of the alloy and the processes required.
[0004] It is also known that the inside of the ingot mould suffers damage, sometimes serious
damage, owing to the mechanical wear caused by introduction of the heads of starter
bars and also by the abrasion of any chills or crystallizers which cooperate with
the starter bar.
[0005] When the head of the starter bar and the chills or crystallizers penetrate within
the passage of the ingot mould, they cause scratches, dents, impacts and various damages,
which not only shorten the life of the ingot mould but also deform its cross section,
thus creating at least malformation of a bar issuing continuously therefrom.
[0006] So as to prevent these shortcomings, the present applicant has designed, tested and
embodied a device having the function of protecting the inside of the ingot mould
temporarily. Such protective cover cooperates with the head of the starter bar and
prevents any contact, even of an accidental nature, between the head of the starter
bar and the inner cooling channel of the ingot mould through which a billet being
cooled passes.
[0007] According to the invention, a jacket having a shape and outer dimensions substantially
suitable to cooperate with the inner channel of the ingot mould is introduced into
the lower terminal portion of the ingot mould.
[0008] The introduction of such protective jacket may be performed before insertion of the
head of the starter bar or in cooperation with insertion of the head of the starter
bar. Such protective cover or jacket then acts as a protective cushion between the
head of the starter bar and the inside of the ingot mould, thus safeguarding the inside
of the latter.
[0009] The protective cover or jacket may have various lengths to suit the form of the crystallizer
and the form and conformation of the removable head of the starter bar.
[0010] The protective cover may be made of various materials; thus it may be embodied with
plywood, compressed and moulded wood dust, plastic foam, cellular resin or moulded
resin, these being some possible but non-restrictive examples, the word "resin" being
understood to cover any desired plastic or synthetic material.
[0011] Moreover, the protective cover may consist of a metallic material having a low or
very low melting point and in this case will be a non-reusable element.
[0012] The material forming the protective cover will advantageously be suitable not to
cause problems during the step of release of the head of the starter bar or else will
be positioned and conformed so as to cooperate with the head of the starter bar and
possibly to be released together with that head.
[0013] In a preferred embodiment the protective cover will be made of a material suitable
to be burned or to be practically destroyed during the casting step or to be rendered
so fragile that it can be readily eliminated during the step of extraction of the
head of the starter bar.
[0014] According to the invention the protective cover can be fitted to the head of the
starter bar before the latter is introduced into the ingot mould, or else it can be
applied to the end portion of the ingot mould before introduction of the starter bar
thereinto. Application can be performed by hand or by a robot, for instance by means
of a manipulator head which withdraws the protective cover from an appropriate storage
point.
[0015] The invention is therefore embodied with a protective cover for a head of a starter
bar in continuous casting, which cover is able to protect the inside of the passage
for a billet being cooled in an ingot mould during continuous casting, being characterized
in that it has a jacket-wise shape and encloses the head of the starter bar at least
partially, being positioned between such head and the inside of the passage for the
billet.
[0016] The invention is also embodied with a starter bar for continuous casting, characterized
in that it cooperates with a protective cover that encloses at least a head of the
starter bar at least partially at least when such head is inside the passage for a
billet being cooled in an ingot mould.
[0017] Let us now see an embodiment of the invention with the help of the attached figures,
which give a non-restrictive example and in which:-
Fig. 1 shows the invention applied to a starter bar having a head which is released
sideways;
Fig. 2 shows the invention applied to a starter bar having a head which remains embdedded
at the end of the billet.
[0018] A starter bar 11 comprising a head 12 with release means 18 is able to cooperate
in an ingot mould 14 having an inflow channel of a required section and characteristics.
[0019] The release means 18 may be of various types and are shown in Fig.1 as being of a
type for extraction by sideways displacement and recovery of the head, whereas Fig.2
shows a type with lateral movement and an expendable head 12.
[0020] Chills 15 or 115 are included in cooperation with the head 12 of the starter bar
11 and have the function of crystallizers to speed up and accentuate the cooling and
engagement of the end of a billet being cast in the ingot mould 14.
[0021] The head 12 of the starter bar 11, the starter bar 11 itself and the crystallizer
chills 15 of Fig.1 are of a known type and may be of any desired type, this being
unimportant for the purpose of the invention.
[0022] In Fig.1 the chills 15 consist of simple crop ends of round metallic bars, as commonly
employed in the art.
[0023] Instead, Fig.2 shows a spiral type of chill or crystallizer 1
15. According to the invention this type of embodiment prevents contact between the
chill 115 and the wall 14 of the ingot mould; it therefore enables a shorter protective
cover 10 to be used since such cover does not need to reach the zone of the chill
115. Pollution of the cast billet by residues of the carbonised protective cover 10
or of gases caused by combustion of the cover is thus avoided.
[0024] A protective cover or jacket 10 is provided to cooperate with the head 12 of the
starter bar 11 and is suitable to cooperate with the inside of the ingot mould 14,
thus preventing the head 12 of the starter bar 11 and the starter bar 11 itself from
knocking or damaging the inside of the discharge channel of the ingot mould 14.
[0025] The protective cover 10 can be applied to the lower part of the ingot mould 14 before
the head 12 of the starter bar 11 is introduced thereinto or else can be fitted to
the head 12 of the starter bar 11 before the head 12 is introduced into the ingot
mould 14.
[0026] The protective cover 10 can be applied by hand or by a manipulator 17 which takes
the cover 10 from an appropriate storage point and positions it.
[0027] If a manipulator 17 is provided, rolls 113 at the end of the starter bar will be
capable of being opened apart so as to enable the protective cover 10 to be positioned.
[0028] Guide rolls 13 may possibly be spaced apart in such a way as to enable the manipulator
17 to operate without contacting the rolls.
[0029] The length of the protective cover 10 will vary to suit the conformation of the head
12 of the starter bar 11 and the inner conformation of the ingot mould 14.
[0030] Moreover, the protective cover 10 may consist of plywood, compressed and/or moulded
wood chips, wood chips plus a filler, glass-reinforced polyester resin, plastic foam
or moulded resin, the name "resin" comprising any known type of plastic or synthetic
material.
[0031] The protective cover 10 may also be made of any material, even a metallic material,
having a low melting point provided that it is soft, so that it will be destroyed
at the time of the casting or will be embedded on the end portion of the billet.
[0032] The protective cover 10 will be positioned and conformed advantageously in such a
way that it will not hinder the releasing of the head 12 of the starter bar 11 at
the time when the starter bar is detached from the billet.
1 - Protective cover (10) for a head (12) of a starter bar (11) in continuous casting,
which cover is able to protect the inside of the passage for a billet being cooled
in an ingot mould (14) during continuous casting, being characterized in that it has
a jacket-wise shape and encloses the head (12) of the starter bar (11) at least partially,
being positioned between such head (12) and the inside of the passage for the billet.
2 - Protective cover (10) as claimed in Claim 1, which is introduced into the inside
of the passage in the ingot mould (14) before the head (12) of the starter bar is
inserted.
3 - Protective cover (10) as claimed in Claim 1, which is fitted to the head (12)
of the starter bar before such head is inserted into the passage for the billet in
the ingot mould.
4 - Protective cover (10) as claimed in any claim hereinbefore, which is applied by
hand.
5 - Protective cover (10) as claimed in any of Claims 1 to 3, of which the application
is mechanized (17).
6 - Protective cover (10) as claimed in any claim hereinbefore, the rolls (113) at
the end of which can be opened apart.
7 - Protective cover (10) as claimed in any claim hereinbefore, which is made of a
material softer than the material of the inside of the ingot mould (14).
8 - Protective cover (10) as claimed in any claim hereinbefore, which is expendable.
9 - Protective cover (10) as claimed in any claim hereinbefore, which cooperates with
a spiral-type chill (115) surrounding the head (12) of the starter bar (11) (Fig.2).
10 - Starter bar (11) for continuous casting, characterized in that it cooperates
with a protective cover (10) that encloses at least a head (12) of the starter bar
at least partially at least when such head is inside the passage for a billet being
cooled in an ingot mould (14).