SU858972A1 - Method of producing hollow parts with branches - Google Patents

Description

(54) METHOD OF MANUFACTURING HOLLOW DETAILS WITH BRANCHES

one

The invention relates to the processing of metals by pressure, in particular the production of articles from billets by pressure.

A known method of punching hollow articles with taps, comprising the steps of placing the workpiece into the cavity of the split matrix, closing the cavity of the workpiece, forming the taps by feeding pressure into the internal cavity with simultaneous face draft of the workpiece after stamping 1.

However, the known method does not allow stamping of parts with high-altitude outlets on which further threading is performed, parts with a diversion diameter significantly smaller than the diameter of the main pipe, from hard-to-deformed high-strength materials, as well as parts of large dimensions, since extremely large deformation and accordingly, the power of the equipment.

As a result, the height of the taps when stamping in a known manner in a number of cases cannot be obtained sufficiently for

use of parts after trimming the bottom parts of the bends.

The purpose of the invention is to improve the quality of products and increase the height of the bends.

This goal is achieved by the fact that - before the precipitate the preform is heated to a temperature above the recrystallization temperature.

The proposed method is carried out as follows.

The tube blank preheated above the recrystallization temperature is placed into the main cavity of the separable matrix, the blank is sealed with axial punches, a certain amount of easily evaporated or boiling liquid, such as water, is injected into the tube blank to create a vapor or gas of the required pressure. Then, axial punches carry out the draft of the initial pipe. Under the action of compressive force and internal vapor or gas pressure, the original pipe is deformed to form a retraction.

When a non-heated billet is stamped due to the hardening of the metal of the pipe sludge, it occurs not only in the retraction zone, but also along the entire length, including at the pipe ends. In the retraction zone, circumferential tensile stresses from the pressure of the internal medium and compressive forces from the axial force act. The tensile stresses contribute to the deformation at low axial stresses. Plastic deformation with the extrusion of material into a moldable outlet begins only in the outlet zone. The tube part is affected by compressive stresses along the axis, as well as compressive circumferential stresses, since the matrix prevents the increase in the transverse dimensions of the workpiece. Here, plastic deformation is difficult and is not observed at the initial shtampovka moment. Due to the plastic deformation of the pipe in the metal withdrawal zone, the axial stresses necessary for the deformation are increased and the accompanying draft of the workpiece along the entire length and at the ends also increase. At temperatures above the recrystallization temperature, the metals are not strengthened, therefore, there will be no thickening of the wall of the main pipe, and the axial loads will be transferred to the deformable E50, where the sediment will concentrate and the outlet will grow more intensively.

Example. A billet with a diameter of 25 X 4 mm, a length of 120 mm from steel 1X18H9T, is heated to 1200 ° C, and has a deformation resistance of 2 kg / mm instead of 68 kg / mm at room temperature. The billet volume is 29.6 cm. For cold punching, an environmental pressure of 3000 kg / cm is required, and hot pressures of 90 kg / cm. To create this

For losing inward, 0.35 g of water is fed in, since the mass of dry steam at 200 ° C and a pressure of 90 kg / cm is 0.35 g. In this case, the blank is cooled to no more than 15 ° C (by heat capacity). Stamping is done in 2 to 5 seconds to reduce heat transfer. Water injection is best done when the billet is not deformed yet. With a draft of 40 mm

the retraction height is 35 mm instead of 20 mm during cold stamping, the retraction has an initial thickness of 4 mm, and the tubular part thickens by only 5% instead of 60% during normal punching.

The use of the proposed method in comparison with the known methods provides: a significant improvement in the quality of the product due to the decrease in the variofibratedness

products, especially when stamping thick-walled products, with bends that differ significantly in diameter from the diameter of the main pipe, as well as from highly strengthened and hard-deforming alloys; increasing the height of the outlet; opportunity

stamping products of complex configuration from high-strength, highly hardened, pure and low-plastic alloys; a significant reduction in the required technological effort, since the stamping is carried out

in a heated state and, consequently, a reduction in the power of the equipment used. In addition, products of equal strength are obtained in all zones and, in a number of cases, there is no need for additional machining of the product.

Claims (1)

Invention Formula A method of manufacturing hollow parts with tee-type elbows by means of axial sedimentation of a tubular billet under pressure from the inside, created mainly by a highly evaporating liquid, characterized in that, in order to improve the quality of products by reducing the wall thickening, as well as increasing Before the precipitate, the billet is heated to a temperature above the recrystallization temperature. Sources of information taken into account at 3KcneRjn3e 1. Japanese Patent No. 41-6450, cl. 12 C 338, 1966.