RU2147260C1 - Apparatus for casting-rolling steel strip - Google Patents

Abstract

FIELD: metallurgy, namely apparatuses for casting-rolling steel strip with use of two-roll machine for continuous casting of billets. SUBSTANCE: apparatus for casting-rolling steel strip includes roll-type crystallizer with lateral limiting walls and pulling stand. Apparatus also includes arranged under crystallizer pulling and rolling stand having at least two pairs of rolls. Rolls have protrusions and recesses alternating along roll barrel. One roll of upper roll pair has disc cutters mounted near ends of roll. Roll protrusions have cylindrical surface, protrusions of rolls of each successive roll pair are arranged with oblique symmetry relative to protrusions of previous roll pair. Each recess of rolls of previous roll pair is closed by protrusions at least of rolls of one successive roll pair. Roll provided with disc cutters may move relative to technological line of apparatus. EFFECT: enhanced quality of strip having no waviness, camber and edge flashes. 4 cl, 2 dwg

Description

 The invention relates to the field of metallurgy, and more particularly to a device for casting-rolling a steel strip using a two-roll continuous casting machine.

 A device is known for casting and rolling a steel strip comprising a roll mold with lateral boundary walls and a pull stand, in which the draw stand is located directly below the mold, and a section of two pairs of guide rollers is installed between the mold and the stand, while and roll stands are smooth (Metec Congress 94, Proceedings, vol. 1, VDEh, 20-22 june, Dusseldorf, 429-437).

 A disadvantage of the known device is the low quality of the strip. This is due to the fact that during intensive cooling, hard crusts of a strip of uneven thickness are formed in the rolls of the crystallizer, which creates the conditions for the appearance of boxing and waviness in strips welded from crusts below the mold. The free movement of the strip along the forming rolls of the mold and the rollers of the section aggravates the development of these defects, and also leads to wear of the lateral bounding walls of the mold and the appearance of gaps at the edges of the strip.

 The closest in technical essence and the achieved result is a device for casting-rolling a steel strip containing a roll mold with lateral bounding walls and a pull stand, in which the rolls of the pull stand are installed in a vertical plane and are made with a smooth barrel (Steel, 1996, N 8, p. 58).

 The disadvantage of the prototype is the low quality of the strip due to gaps at the edges, as well as developed warping and undulation, which is associated with the free movement of the strip along the forming rolls of the mold.

 The technical result of the invention is to improve the quality of the strip - the elimination of its warping and waviness, as well as gulfs on the edges.

 The result is achieved by the fact that the known device for casting-rolling a steel strip containing a roll mold with lateral boundary walls and a pull stand, according to the invention further comprises a draw stand with at least two pairs of rolls arranged alternating along the length of the barrel protrusions and depressions, and one of the rolls of the upper pair is equipped with circular knives mounted at the ends. The protrusions of the rolls are made with a cylindrical surface, while the protrusions of each subsequent pair of rolls are placed obliquely with respect to the protrusions of the previous pair, each depression of the previous pair of rolls is overlapped by the protrusions of at least one subsequent pair of rolls and rolls with circular knives made with the possibility of movement relative to the technological line of the device.

 The claimed combination of features, namely, a stand-rolling stand placed under the mold, the number of roll pairs in the stand, roll barrel profile, circular knives on one of the rolls of the upper pair, excludes the development of waviness and warping of the strip and dips on its edges by ensuring a constant strip position relative to the rolls of the mold, and also eliminates these defects due to the rolling of the strip and with developed debris - due to trimming the edges of the strip.

 The cylindrical surface of the protrusions, their skew-symmetrical placement in subsequent pairs of stands rolls relative to previous pairs and the overlapping of the hollows of the previous pair of rolls with the protrusions of subsequent pairs provides a high-quality flat strip surface, and the implementation of the roll with circular knives with the ability to move relative to the technological line of the device reduces metal consumption with satisfactory as the edges of the strip.

 The invention is illustrated by drawings, where in FIG. 1 and FIG. 2 shows a diagram of a device.

 The device contains two cylindrical water-cooled rolls 1, to the ends of which the restrictive plates 2 are pressed, the surfaces of which and the rolls form a container for metal — a mold 3 guiding 4 strips, a rolling mill stand 5 with two and a large number of pairs of rolls 6, one of which the upper pair has circular knives 7, and a pulling stand (not shown). The rolls of the rolling mill stand 5 are made with protrusions 8 and depressions 9 alternating along the length of the barrel, while the protrusions of each subsequent pair of rolls are placed obliquely with respect to the protrusions of the previous pair and each depression of the previous pair of rolls is overlain in the light by the protrusions 1 ... 2 of the following pairs smooth surface strip 10.

 The device operates as follows. Metal is fed into the mold 3 formed by the surfaces of the rolls 1 and plates 2. Formed in the mold cast strip 10 enters through the guide 4 into the rolling mill stand 5 with a pair of rolls 6 and then into the pulling mill. In the pull-rolling stand 5, strip 10 is rolled by projections 9 of the first pair of rolls 6 to form a periodic profile, the protrusions of which are eliminated when the projections 9 are rolled by subsequent pairs of rolls 6. At the same time, with significant development of the gulfs, the edge of strip 10 is cut with knives 7 of the roll of the upper pair.

 In the absence of gulfs, rolling of the strip begins with the second pair of rollers 6, with rolls of the upper pair removed from the technological line of the device.

 Thanks to the alternate rolling of individual sections of the strip, a stable, constant position of the strip relative to the roll mold is ensured, which suppresses the development of waviness and warping and the formation of gaps at the edges, and together with trimming the defective edges, if necessary, eliminates these defects that originated in the mold.

 The invention can be used to produce a steel strip with a thickness of 2 ... 6 mm and a width of up to 2000 mm from steel with high surface requirements, in particular from electrical and stainless steel. The yield of group 2a over the surface reaches 95%.

Claims (4)

 1. Device for casting-rolling a steel strip containing a roll mold with lateral bounding walls and a pull stand, characterized in that it further comprises a pull-roll stand placed under the mold with at least two pairs of rolls made with alternating lengths barrels with protrusions and troughs, and one of the rolls of the upper pair is equipped with circular knives installed at the ends.  2. The device according to claim 1, characterized in that the protrusions of the rolls are made with a cylindrical surface, while the protrusions of each subsequent pair of rolls are placed obliquely with respect to the protrusions of the previous pair.  3. The device according to one of p. 1 or 2, characterized in that each cavity of the previous pair of rolls is blocked by the protrusions of at least one subsequent pair of rolls.  4. The device according to claim 1, characterized in that the roller with circular knives is arranged to move relative to the processing line of the device.

Images