SU1560347A1 - Method of producing bars from low-ductile materials - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in the manufacture of bar-type products from materials with limited ductility, including refractory metals and alloys. The purpose of the invention is to increase productivity. The method of manufacturing rods of low-plastic materials involves preheating the rod 4 and shell 1 to temperatures at which the yield stress of the shell material exceeds the yield stress of the rod material at their deformation temperatures, inserting the rod into the shell and then co-drawing them together in the deforming matrix 3 under the action of the t force applied to the shell and the pushing force applied to the rod. In this case, a pushing force is created by passing a bar with a shell through an additional deforming matrix 2 installed in front of the matrix 3. 1 sludge.

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of products such as rods from materials with limited ductility, including refractory metals and alloys.

The purpose of the invention is to increase productivity.

The drawing shows a diagram of the deformation of the proposed method.

The bar of a non-plastic material and the casing are heated before deformation to temperatures at which the yield stress of the casing is higher than 15 the yield stress of the bar. In the particular case, if the ductility of the shell is sufficiently high at room temperature, it is not heated before deformation. 20

The shell 1 is introduced with a pointed end into sequentially deforming matrices 2 and 3 and capture traction body. After this, the rod 4 is introduced into the shell 1 and under ^: 25 the action of the force P ^ applied to the shell, is pulled through the matrix 2, 3.

During the passage of the rod in the shell through the matrix 2, the shell βθ receives compression like a tube on a movable mandrel, the role of which is played by the rod. Thereby, the casing is pressed against the bar. Next, the bar with the sheath enters the deforming matrix $ 3, where they undergo joint deformation. In this case, the shell is drawn under the action of a pulling force applied to it, and the rod is pushed through to matrix 3 by the force applied to it in the deformation zone of the additional deformation matrix 2.

For pushing the rod through d $ deforming matrix 3 requires force

P _o = (TTDo / 4) G ' _{S0 ln} pi, where (7 _S0 is the average value of the yield stress of the material · · _ep 5U of the rod at a rate <· ₂ deformation strain;

'= D _o / D ₍ is the coefficient of drawing of the rod in the deforming matrix 2;

D ₀ , D _t - the diameter of the rod, respectively, before deformation and after deformation in matrix 2.

The indicated force P _o according to the proposed method is created due to friction between the shell and the rod in the deformation zone of the additional matrix 2. The maximum value of the friction stress in this case • The minimum value of the friction stress is zero (at the output of the bar from the calibrating zone of the additional matrix) '

L _ A ⁶ MII ^and

The average value of ^voltage friction cf. ~ ⁽⁶ max ^{+ i} min) / 2 = 650/4, and the voltage generated by "push force sr

P _o = (C _cf D _O 1/4 (2) where 1 is the length at which the casing is pressed against the bar.

According to figure ^{1 1} = H ⁺ where lg is the length of the deformation zone;

1 _k - the length of the calibrating part of the matrix 2.

Equating P _o from (1) and (2), we obtain CiD * / 4) G5 _{0 lnf} U = ^ D _o 16 _So / 4, whence we determine the necessary length of 1 section, on which the shell 1 is pressed against the bar 4 = D _o l _n | W. ABOUT)

Given that the range of real hoods (U = 1.1-1.4, from (3) we get 1 = (0.1-0.3) D _S , which is quite acceptable, since in practice only the length of the gauge part of the matrix is about 0.25D _o .

According to the invention, the creation of a pushing force by pressing the sheath against the bar at the entrance to the deformation matrix 3 eliminates the use of a special pushing organ, for example, a wedge self-braking clamp for the bar, its movement mechanism and drive (energy source). deforming matrix, since the pushing force is applied in the immediate vicinity of the entrance to the matrix, and the possible magnitude of this force is not limited by the stability of weaving.

Claims (2)

Claim 1. A method of manufacturing rods from low-plastic materials, including preheating the rod and the sheath to temperatures at which the yield stress of the sheath material exceeds the yield stress of the material of the rod, introducing the rod into the sheath and then pulling them together in the deforming matrix under the action of a pulling force applied to the shell and a pushing force applied to the rod, characterized in that, in order to increase productivity, the pushing force is applied to the rod at the entrance to the def shaping matrix. 2. The method according to claim 1, characterized in that a pushing force is created by passing the rod with the sheath through an additional deformation matrix, placed in front of the main one.