RU2062671C1 - Method of making strip rectangular high-accuracy shapes - Google Patents

Abstract

FIELD: rolled stock production, namely, production of high-accuracy strip profiled blanks in specialized shops of machine engineering plants. SUBSTANCE: method comprises formation of cross section of octahedral blanks while taking into account normalized values of angle α between adjacent inclined faces and width of flat portion of bases D, D₁. Such normalization allows to receive due to combination of assembling octahedral blanks to builtup blank and repetitive rolling of builtup blank in edge and four-roll non-adjustable roll grooved passes as series of experimental rolling procedures had shown two types of dimensions of shapes in the same set of rolls. Method provides production of shapes having thickness less than 1.5 mm, enhanced efficiency, decreased number of rolls being used and lowered labor consumption at making edge grooved pass. EFFECT: enlarged manufacturing possibilities, enhanced efficiency. 1 cl, 7 dwg

Description

 The invention relates to rolling production and can be used in the production of high-precision strip profiles in the conditions of specialized workshops for the production of shaped profiles and procurement of engineering enterprises.

 A known method for the production of strip steel by rolling on a smooth barrel with subsequent control of the strip width in rib calibers.

 The disadvantages of this method are in violation of the flatness of the non-compressible sections of the strip, which limits the possibilities of the method when forming cold-rolled high-precision strip profiles.

 Closest to the invention is a method comprising sequential shaping of an initial rectangular blank in a gauge system including box and rib gauges and finishing rolling of a rectangular strip profile.

The use of the known method for the production of high-precision cold-rolled rectangular sections is limited for the following reasons:
the presence of a large fleet of rolls (each standard size of a rectangular profile requires an individual set of rib and finishing calibers);
lack of technical ability to obtain profiles with a thickness of less than 1.5 mm;
low level of productivity (piece rolling);
high complexity of manufacturing rolls of rib caliber when rolling thin strips with a thickness of 1.0.2.0 mm;
low rolling accuracy (there is no possibility of simultaneous control of profile dimensions in height and width when rolling in a finishing gauge).

 The invention eliminates these disadvantages, which leads to the possibility of manufacturing rectangular strips with a thickness of less than 1.5 mm, reducing the fleet of rolls due to the unification of calibers, increasing productivity and reducing the complexity of manufacturing rib rolls. This is achieved by the fact that in the known method for the production of rectangular rectangular high-precision profiles, which includes sequential shaping of the initial rectangular billet in the gauge system, including box and rib calibers, and finishing rolling of the rectangular strip profile, according to the invention, the initial rectangular billet is rolled in a rib caliber, forming from it an octagonal draft blank, which is then rolled in a four-roll rectangular gauge, the resulting rectangular agotovku rolled in caliber pans again octagonal workpiece to a thickness of half the thickness of the blister octagonal billets produced octagonal billets pairwise dock on the bases, and the collected composite preform successively deformed at the fin and rectangular four-high finishing calibers.

, где b₁ ширина готового прямоугольного проaиля, R радиус сопряжения граней готового профиля, Δh₂ величина абсолютного обжатия горизонтальными валками четырехвалкового калибра, α угол между соседними наклонными гранями восьмигранных заготовок, а величину упомянутого угла a выполняют одинаковой для каждой из восьмигранных заготовок в пределах a 60^o.96^o.In addition, the width of the flat part of the base of the draft (Δ) and formed in the box caliber (D) of octahedral blanks is performed respectively within

, where b _{1 is the} width of the finished rectangular section, R is the radius of conjugation of the faces of the finished profile, Δh ₂ is the absolute compression by horizontal rolls of a four-roll caliber, α is the angle between adjacent inclined faces of the octagonal blanks, and the value of the mentioned angle a is the same for each of the octagonal blanks within a 60 ^o .96 ^o .

 Ensuring the technical feasibility of manufacturing strips with a thickness of less than 1.5 is achieved by rolling in the rib caliber of a composite billet, each part of which is equal in thickness to half the thickness of the rough octagonal billet and has equal angles between the inclined adjacent faces with the draft billet. At the same time, each of the blanks of the composite blank interacts with the inclined walls of a common rib gauge (width of a common gauge> 1.5 mm) along the external inclined faces, hence the negative effect of friction forces on filling the bottom of the gauge with metal is halved.

 Due to the fact that the rigidity of the composite billet is higher than single, it is possible to roll in rib calibers with a ratio of width to strip thickness of more than five times. The possibility of deformation of strips in a rib gauge with a ratio of width to strip thickness of ≅ 6.2 was experimentally confirmed.

 Essentially, thanks to the rolling of the strips in the docked form, the complexity of grinding the rib rolls is reduced.

, позволяет обеспечить получение радиусов сопряжений граней готового профиля в соответствии с требованиями чертежа. Причем, как показали экспериментальные исследования, выполнения угла α <60^o сопровождается незаполнением оснований прямоугольных профилей, выполнение угла, a> 96^o образованием "усов", получение заготовок с величинами D и D₁, меньшими регламентируемых, связано с нарушением плоскостности оснований, с большими для внутренних граней с получением более острых, чем требуется по чертежу кромок, а для наружных граней с образованием "усов".The implementation of the angle a between adjacent faces and the width of the flat part D, D _{1 the} base of the octagonal blanks respectively equal to α 60.96 ^o ,

, allows to obtain the radii of the mates of the faces of the finished profile in accordance with the requirements of the drawing. Moreover, as shown by experimental studies, the fulfillment of the angle α <60 ^{o is} accompanied by the non-filling of the bases of rectangular profiles, the execution of the angle, a> 96 ^{o by the} formation of a "mustache", the preparation of workpieces with D and D ₁ values less than regulated is connected with the flatness of the bases, with large for internal faces to produce sharper edges than required by the drawing, and for external faces with the formation of "whiskers".

, а при прокатке составной заготовки в четырехвалковом калибре по плоскости контакта наблюдается (из-за наличия "прилипания" заготовок), меньшая, чем на контакте заготовок с валками интенсивность уширения.The inequality of the values of Δ, D _{1 is} caused by the fact that when the composite workpiece is deformed in the rib caliber, there is an increase in Δ ₁ along the contact plane of the workpieces to the value

and when rolling a composite billet in a four-roll gauge along the contact plane, the broadening intensity is lower (due to the presence of "sticking" of the billets), which is lower than at the contact of the billets with the rolls.

 The reduction of the roll park is ensured by repeated rolling of octagonal billets using rib and four-roll unregulated calibers. Hence, in the production of rectangular profiles, the roll park is at least six rolls smaller.

 Improving the accuracy of rolling is caused by the simultaneous control of the strip sizes in width and height during its deformation in a four-roll caliber.

 In FIG. 1 shows a deformation diagram of a hot-rolled strip in a rib gauge; FIG. 2 shows a diagram of the deformation of an octagonal workpiece in a four-roll gauge; FIG. 3 a deformation diagram of a high-precision rectangular profile in a box gauge; Fig. 4 a deformation diagram of a composite workpiece in a rib caliber; Fig. 5 a deformation diagram of a composite workpiece in a four-gauge caliber; Fig. 6.7 high-precision strip rectangular profiles.

 The method is as follows.

где b₁ ширина готового прямоугольного профиля, Δh₂ величина абсолютного обжатия заготовки в четырехвалковом калибре, R радиус сопряжений граней готового профиля. Полученную восьмигранную заготовку 3 деформируют в четырехвалковом калибре 4в прямоугольную полосу 5 с высотой h₁ и шириной b₁ и далее задают в ящичный калибр 6, где получают восьмигранную заготовку 7 с толщиной, равной половине толщины восьмигранной заготовки 3 и шириной плоской части основания

Восьмигранные заготовки 7 попарно стыкуют по основаниям в составную заготовку 8, толщина которой равна толщине заготовки 3 и не меняя взаимного положения частей заготовки 8 повторно деформируют в калибрах 2 и 4.An initial billet, for example, a hot-rolled strip 1 is rolled in a rib caliber 2 into an octagonal billet 3 with an angle between adjacent inclined faces of α 60.96 ^o and the width of the flat part of the base

where b _{1 is the} width of the finished rectangular profile, Δh ₂ is the absolute compression of the workpiece in a four-roll gauge, R is the radius of the mating faces of the finished profile. The obtained octagonal preform 3 is deformed in a four-roll gauge 4 into a rectangular strip 5 with a height of h ₁ and a width of b ₁ and then set into a box gauge 6, where an octagonal preform 7 is obtained with a thickness equal to half the thickness of the octagonal preform 3 and the width of the flat part of the base

The octagonal blanks 7 are joined in pairs on the bases into a composite blank 8, the thickness of which is equal to the thickness of the blank 3 and without changing the relative position of the parts of the blank 8 is deformed again in gauges 2 and 4.

а по наружным основаниям под воздействием наклонных стенок калибра формируется до величины

При прокатке составной заготовки 8, имеющей наружный описанный контур поперечного сечения в виде симметричного восьмигранника, а поперечные сечения заготовок 7 несимметричных восьмигранников, каждая из заготовок формируется в идентичные готовые профили и вследствие того, что различие в граничных условиях по наружным и внутренним граням заготовок 7 учтено при черновом формировании, радиусы сопряжений всех граней соответствуют требованиям чертежей на готовые профили.When forming a composite workpiece 8 in caliber 2, the width of the flat parts of the bases of the workpieces 7 along the contact plane increases to

and on external bases under the influence of inclined walls of the caliber is formed to a value

When rolling a composite billet 8 having an external described contour of the cross section in the form of a symmetric octahedron, and the cross sections of the billets 7 are asymmetric octahedrons, each of the billets is formed into identical finished profiles and due to the fact that the difference in the boundary conditions for the outer and inner faces of the billets 7 is taken into account when roughing, the radii of the mates of all faces correspond to the requirements of drawings for finished profiles.

It should be noted that the identity of the cross-sectional dimensions of the finished profiles obtained during the rolling of the composite billet is provided:
the implementation of the principle of symmetrical workpiece symmetrical caliber,
the centering effect of the rolls on the components of the workpiece;
the identity of the sizes of the initial blanks.

 According to the proposed method, experimental batches of rectangular strip profiles of two sizes were rolled (see figure 6.7). Material profiles steel 10 GOST 1050-74. A hot-rolled strip with a cross-sectional size of 3x12 mm was used as the initial billet. Rolling was carried out in five passes through three calibers (see Fig. 1-5) on a 150/150 mill with a four-roll caliber. All calibers were assembled in a closed circuit (in the lock) with preliminary loading. The rolling speed was 0.6 m / s. Emulsol cooling 32 GOST 1975-75.

In the first rib caliber from a strip of 3x12 mm, an octagonal workpiece was formed with a width of 10.4 mm, a height of 3.4 mm, an angle between inclined adjacent faces of 60 ^o and a width of the flat part of the base Δ 6.7 mm The hood in the rib passage was l 1.13. When rolling an octahedral workpiece in a four-roll gauge (see Fig. 2) with a hood of 1.34, a rectangular profile was obtained with cross-sectional dimensions that fully met the requirements of the drawing (see Fig. 7). The resulting rectangular profiles were deformed in a box gauge (see Fig. 3) with an extract l1.365 into an octagonal workpiece with the following cross-sectional dimensions: the width of the flat part of the base D _{1 was} 8.25 mm, the thickness of the workpiece 1.68 mm, the angle between adjacent inclined faces α60 °. Next, the octagonal billets were assembled into a composite billet and rolled without changing the relative position of its components in the rib (see Fig. 1.4) and four-roll (see Fig. 2.5) calibers with hoods, respectively 1.04; 1.36. Before rolling the composite billet with a pressure device, the loading force of the rib and four-roll calibers was adjusted.

8,54 мм, а по наружным граням Δ 6,74 мм. При деформации составной заготовки в четырехвалковом калибре получено из каждой составной заготовки по два прямоугольных профиля, размеры поперечных сечений которых соответствовали требованиям чертежа (см.фиг.6).As a result of rolling the composite billet in the rib gauge, the width of the flat part of the base along the contact plane was

8.54 mm, and on the outer faces Δ 6.74 mm. Upon deformation of the composite workpiece in a four-roll gauge, two rectangular profiles were obtained from each composite workpiece, the cross-sectional dimensions of which corresponded to the requirements of the drawing (see figure 6).

To determine the optimal values of the angle a between adjacent inclined faces, 8 sizes of octagonal blanks with angles a 50 ^o were prepared; 55 ^o ; 65 ^o ; 80 ^o ; 85 ^o ; 90 ^o ; 96 ^o ; 98 ^o and a thickness of 3.4 mm.

When rolling billets with an angle a <60 ^o , the bases of rectangular profiles were not filled, and when forming billets with an angle a 96 ^{o, the} formation of a "mustache" (when passing single billets through a four-roll gauge along all edges, and when rolling a composite billet along the outside).

 The effect of changing the regulated range of the width of the flat part of the base of the octagonal blanks on the quality of the finished profiles was determined (with the declared limits of the deviations of the angle between adjacent inclined faces) by phased regrinding of calibers (see figure 1-3). A hot-rolled billet of 3x12 mm was used as the initial billet.

As a result of a series of experimental rolling and measuring the dimensions of the obtained rectangular profiles, it was found that rolling in a four-roll gauge of single and composite billets with D and D ₁ values less than regulated is accompanied by a violation of the flatness of the bases of the rectangular profiles, larger for the inner faces of the composite strip, due to sharp edges, and for the outside with the formation of a "mustache".

Subsequent rolling of test batches of various sizes of rectangular profiles confirmed that the proposed regulation of angles α and values D and D ₁ provides the required quality profiles of a wide range, and when rolling thinner strips, preferably smaller, within the proposed ranges, the values of α, D and D ₁ . YYY2 YYY4 YYY6

Claims (2)

 1. A method of manufacturing a strip of rectangular rectangular high-precision profiles, including sequential shaping of the original rectangular billet, in a gauge system including box and rib calibers, and finishing rolling of a strip rectangular profile, characterized in that the rolling of the initial rectangular billet is carried out in a rib caliber, forming an octagonal draft blank, which is then rolled in a four-roll rectangular gauge, the resulting rectangular blank is rolled in a box caliber with ova in octahedral preform to a thickness of half the thickness of the blister octagonal billets produced octagonal billets pairwise dock on the bases, and the collected composite preform successively deformed at the fin and finishing rectangular chytyrehvalkovom calibers. 2. The method according to claim 1, characterized in that the width of the flat part of the base of the draft (Δ) and formed in the box caliber (D ₁ ) of octagonal blanks is performed respectively within

where b _{1 the} width of the finished rectangular profile;
R is the radius of conjugation of the faces of the finished profile;
Δh ₂ - the absolute compression of the workpiece by horizontal rolls of four-roll caliber;
α is the angle between adjacent inclined faces of the octagonal blanks,
and the value of the angle a is the same for each of the octagonal blanks within α = 60-96 ^° .

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