SU755336A1 - Rolling method - Google Patents

Description

The invention relates to the field of metal pressure treatment, in particular to the technology of rolling production. five

There is a known method of rolling billets, including the sequential formation of several rectangular billets from a slab in multi-grooves simultaneously connected to each other by pe-Yu, dividing the thickness of the jumpers to 0.02-0.025 of the height of the gauge. After this, the billet is separated, holding the middle billet, and relative to it along the edges 15, the remaining blanks are displaced in the opposite direction on each side, with each subsequent caliber being shifted by a larger amount as the distance from the average blank is [one]. 20

Known technical solution has the following disadvantages: low surface quality of the workpieces in places of separation, caused by the mutual indentation of the edges of the profiles in places 25 of separation; the possibility of obtaining the twisting of the extreme profiles around their longitudinal axis after separation as a result of the wear of the separating gauge. .thirty

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There is also known a rolling method that includes the sequential formation of a flat billet in multi-strand, mainly in three-strand gauges of a multi-strand roll consisting of several interconnected profile jumpers, and their subsequent separation along jumpers by displacing the extreme profiles along the aligned faces [2].

However, this technical solution does not eliminate the possibility of reciprocating the edges of the profiles at the point of separation and twisting the extreme blanks around their longitudinal axis at the point of separation due to the rotation of the extreme profiles around the jumpers at the moment of separation.

The described rolling method does not have these drawbacks and differs in that before entering a multi-strand roll into the deformation center of the separating caliber, at least one of the displaced profiles is turned around the jumper by an angle of 2-15 in the direction of the top of the middle stream. with a maximum depth of incision, for example, by exposing it to the core reinforcement and keep in such

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position until final separation.

Thus, the reversal of the blanks is compensated in the separation process, which prevents the formation of twisting of the displaced profiles along their longitudinal axis. The interval of the turning angles is determined by the plastic moment of resistance to twisting.

Thus, with a turning angle of not less than 2 °, the desired effect will not be / is achieved even with steels with a maximum value of the moment of resistance. The upper value of the interval is determined by the minimum value of the plastic moment of resistance; in addition, when turning ’to an angle of 15 ° and the subsequent 'separation, there is a distortion of the geometrical dimensions of the profile.

The essence of the method is illustrated in the drawing, which presents a diagram of the reversal of the profiles before the separation.

Extreme profiles 1 and 2 turn around the jumpers 3 at an angle of 2 to 15 ° to the position shown in the drawing by a solid line, and hold in this position, for example, at. the help of the downstream reinforcement before the final separation, the turning angle at which the reinforcement retains the extreme profiles is chosen so that in the deformation zone there is a turn in the opposite direction by the same angle value to the position shown in the figure by the dotted line. Due to this, the division turns off the further reversal.

Example. Slab rolling is performed in two three-strand gauges embedded into rolls with a diameter of 2–70 mm of a 20C mill. The draft caliber consists of three combined speech: medium square with a side of 28 mm and extreme rectangular 28 * 31 mm. When great. no gap between the pins of 2.5 mm caliber, the sides of rectangular streams, adjacent to the middle, coincide with the intersecting sides of the middle square stream. Finishing caliber consists of three square speech, combined sides with a gap of 5 mm. The sides of square streams are 28 mm. Lead oxide 10

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The 34 × 45 * 51) 0 mm dimensions for four passes are rolled in a rough gauge to a jumper thickness of 2.5ί mm. Before rolling the roll in the second caliber, intended for separation, the extreme blanks are turned at an angle of 10 ° in the direction of the top of the middle stream with a maximum depth of incision by exposing them to the root fixture. In the process of separation, they are held in this position with the help of core fittings until complete separation. At the same time, after separation, the twisting of the extreme profiles, as well as the mutual indentation of the edges of the profiles, is not observed.

Claims (1)

Claim The rolling method, which includes the sequential formation of a flat billet in multi-strand, mainly in three-strand gauges of a multi-strand roll consisting of several profiles interconnected by bridges, and their subsequent separation into bridges by shifting the extreme profiles along the aligned faces, characterized in that improving the quality of the metal by preventing mutual indentation of the edges of the profiles at the point of separation and their twisting, before entering the multi-line roll into the strainer ii separating fire at least one of the displaceable profiles rotated around the web at an angle of 2 - 15 ° towards the middle of the stream the top with a maximum depth of incision, e.g., through exposure to 'on it roll guides the armature and is held in this position until the final separation.