RU2138358C1 - Method for rolling out annular blanks - Google Patents

Abstract

FIELD: plastic metal working, namely processes for rolling out annular blanks. SUBSTANCE: at any stage of rolling out process current value of inner diameter (Di) including its final value is determined according to reduction value ((Δti)) used in relation Di=f((Δti)) while taking into account initial size of blank. It allows to continuously measure diameter of rolled out blanks. EFFECT: enhanced accuracy at rolling out annular blanks. 5 cl, 13 dwg

Description

 The invention relates to the processing of metals by pressure, in particular, to methods for manufacturing ring blanks for parts of gas turbine engines, and can be used in engineering industries where ring-shaped rectangular products without grooves or with grooves inside and / or outside are made.

 A known method of manufacturing ring billets by rolling on ring mills in a closed gauge (without broadening) [1], which allows to obtain finished products with a wide range of sizes in cross section and in diameter. Depending on the reserve of plasticity and deformation resistance of the materials used, as well as on the size of the cross section of the products, they are rolled out in hot or warm conditions, or even without any special heating.

 The disadvantage of this method is that when it is in the process of rolling it is possible to fix only the moment of reaching the final diameter of the rolled product when the disconnecting device is activated [1, p. 104]. In fact, all rolling processes allow fixing only the final diameter value in the deformable product. Direct measurements of the diameter of the ring blanks during the rolling process are complicated primarily by the fact that they thus acquire an irregular (different from a circle) shape.

 The technical result of the invention is the ability to continuously determine all the current values of the inner diameter from the moment the start of rolling until the final size of the rolled product. It should be borne in mind that all ring blanks, depending on the presence or absence of recesses in rectangular sections, can be divided into four types: smooth inside and out; with recesses from the inside; with recesses outside; with recesses inside and out.

где K₁ и K₂ - коэффициенты формы сечения заданной кольцевой заготовки, определяющие степень его отклонения от прямоугольного сечения; t - толщина сечения исходной заготовки, мм; D - внутренний диаметр исходной заготовки, мм; Δt_i - величина общего обжатия на данной стадии раскатки, равная t - t_i, мм; t_i - толщина сечения на данной стадии раскатки, мм.The specified technical result is achieved by the fact that the ring blanks the current value of the inner diameter D _i at any stage of the rolling process, up to the final, is continuously determined by the amount of compression from the ratio:

where K ₁ and K ₂ are the coefficients of the shape of the section of a given annular workpiece, determining the degree of its deviation from the rectangular section; t is the thickness of the cross section of the original billet, mm; D is the inner diameter of the original billet, mm; Δt _i - the total reduction at this stage of rolling, equal to t - t _i , mm; t _i is the thickness of the section at this stage of rolling, mm

For ring blanks, smooth inside and out, the coefficients K ₁ and K ₂ are equal to unity.

For annular blanks with recesses from the inside, the coefficients K ₁ and K _{2 are} determined from the relations
K ₁ = 1-αβ; K ₂ = 1-αβ ² ,
where α is the coefficient of the width of the section, equal to h '/ h _i ; β is the coefficient of thickness of the cross section equal to t '/ t _i ; h 'is the height of the recess from the inside of the section, mm; t 'is the depth of the recess from the inside of the section, mm; h _i - section height at this stage of rolling, mm.

For annular blanks with recesses on the outside, the coefficients K ₁ and K _{2 are} determined from the relations
K ₁ = 1-γφ; K ₂ = 1-2γφ + γφ ² ,
where γ is the coefficient of the width of the section, equal to h "/ h _i ; φ is the coefficient of thickness of the cross section equal to t '' / t _i or Δt _i / t _i when Δt _i <t ″; h '' is the height of the recess outside the section, mm; t '' is the depth of the recess outside the section, mm.

For annular blanks with recesses inside and outside the section, the coefficients K ₁ and K _{2 are} determined from the relations
K ₁ = 1-αβ-γφ; K ₂ = 1-αβ ² -2γφ + γφ ² .
The values of the coefficients α and γ are always calculated according to the dimensions indicated in the drawing of the given annular blank. In the case (for example, in the initial stage of rolling), when the amount of compression does not exceed the size of the recess in the cross section (according to the drawing), the values of the coefficients β and φ are determined on the basis that the recess is numerically equal to the size of the compression. In the case when the total compression numerically exceeds the size of the recesses in the section (for example, in the final stage of rolling), the coefficients β and φ, as well as the coefficients α and γ, are calculated according to the dimensions indicated in the drawing.

The dependencies proposed in the claimed method are obtained on the basis of the new law of rolling blanks in closed gauge (which is a consequence of the assumption that the volume of metal in the initial, intermediate and final stages of rolling blanks is constant), established in [2] is the product of the thickness of the section by the diameter of the circle passing through the middle of this thickness is a constant value for each annular blank at any stage of rolling:
t • (D + t) = t _i • (D _i + t _i ) = Const
A comparative analysis of the new technical solution with the prototype shows that the claimed method differs from the known one in that it allows you to continuously (at any stage of rolling) determine the inner diameter, from the original to the final, and this is done extremely simply - only by the amount of compression. As you can see, in the prototype method this advantage is not, because it generally determines only the outer diameter, and only at the end of rolling, due to the disconnecting device.

 The invention is illustrated by drawings. In FIG. 1 is a cross-sectional view of an annular blank smooth inside and out, FIG. 2-5 sections with recesses from the inside, in FIG. 6-9 are cross-sections with recesses outside and in FIG. 10-13 sections with recesses inside and out.

The proposed method is tested on various materials (EYA1T, EI435, VZh98, EP708 VD, OT4-1, VT20, etc.) in cold, warm, and hot conditions. For the initial blanks with a diameter of 300-550 mm with cross-section sizes from 20 x 60 mm to 50 x 120 mm, reductions of 5, 10, 15 mm and others were set, for which diameters were calculated ahead of time and compared with actual measurements. The results of these measurements for various types of cross sections are fully consistent with the calculated ones (with deviations of less than 1 mm in rare cases when the initial cross section does not have a strictly rectangular shape, i.e., when the corner zones are rounded). In the case of an irregular final shape of the finished product (other than a circle), the accuracy of rolling was checked along the length of the reamer (π • D _i ). Compliance with the calculated and actual scan lengths is always high. Therefore, the actual results due to the bulkiness are not given.

Sources of information
1. Zubkov A.I., Lebedev V.N. and other production of ring blanks. - M.: Central Research Institute of Information, 1980, 284 p.

 2. Protsiv Yu.V. On the calculation of the parameters of rolled ring blanks. Aviation industry. - 1993, N 2, p. 36-39.

Claims (4)

1. The method of rolling ring billets of rectangular cross section from various metal materials on ring rolling mills in a closed gauge in cold or hot condition, including deformation with continuously or discretely increasing compression to obtain the desired specific value of the inner diameter, characterized in that the current value of the inner diameter D _i at any stage of the rolling process up to the final one, it is determined by the amount of compression from the ratio

where K ₁ and K ₂ are the coefficients of the shape of the section of a given annular workpiece, determining the degree of its deviation from the rectangular section;
t is the thickness of the cross section of the original billet, mm;
D is the inner diameter of the original billet, mm;
Δt _i - the total reduction at this stage of rolling, equal to tt _i , mm;
t _i is the thickness of the section at this stage of rolling, mm 2. The method according to claim 1, characterized in that for the ring blanks, smooth inside and out, the coefficients of the shape of the cross section K ₁ = K ₂ = 1. 3. The method according to claim 1, characterized in that for ring blanks with recesses from the inside, the coefficients of the shape of the cross section K ₁ and K _{2 are} determined from the ratios
K ₁ = 1-αβ; K ₂ = 1-αβ ² ,
where α is the coefficient of the width of the section, equal to h '/ h _i ;
β is the coefficient of thickness of the cross section equal to t '/ t _i ;
h 'is the height of the recess from within the section, mm;
t 'is the depth of the recess from the inside of the section, mm;
h _i - section height at this stage of rolling, always constant from the beginning to the end of the rolling process, i.e. h _i = h, where h is the height of the cross section of the original workpiece, mm 4. The method according to claim 1, characterized in that for the ring blanks with recesses on the outside, the coefficients of the shape of the cross section K ₁ and K _{2 are} determined from the ratios
K ₁ = 1-γφ; K ₂ = 1-2γφ + γφ ² ,
where γ is the coefficient of the width of the section, equal to h "/ h _i ;
φ is the coefficient of thickness of the cross section equal to t "/ t _i or Δt _i / t _i when Δt _i <t ″;
h "is the height of the recess outside the section, mm;
t "is the depth of the recess outside the section, mm;
5. The method according to claim 1, characterized in that for ring blanks with recesses inside and out, the coefficients of the shape of the cross section K ₁ and K _{2 are} determined from the ratios
K ₁ = 1-αβ-γφ; K ₂ = 1-αβ ² -2γφ + γφ ² .

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