SU532638A1 - The method of strengthening products - Google Patents

Description

one

The invention relates to the field of engineering, in particular to methods of thermomechanical strengthening of products, and can be used in the manufacture of forging tooling.

Thermomechanical hardening methods are known that are carried out according to the following technological scheme: heating to austoonization temperature, plastic deformation, hardening from deformation heating, and tempering

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Known methods do not provide

the ability to manufacture products of high alloy steels and a complex form of crack formation, and the high hardness after quenching makes it difficult to remove the stamping allowances by machining.

Of the known technical solutions, the closest is the method of strengthening, which includes heating the workpiece to the austenization temperature, plastic deformation, quenching from deformation heating, tempering, mechanical processing, final quenching and G2T tempering.

The disadvantage of this method is the significant warping of 1 complex-shaped buildings made of highly alloyed steels.

The purpose of the invention is to prevent warping and cracking in the manufacture of products by thermomechanical treatment.

This is achieved by including in the known method, heating the workpiece to austenization temperature, plastic deformation, 3aivanKy, tempering, MexaHH4ecK To processing, final quenching and tempering, after deformation the product is cooled to a temperature of 30-90 C below A i, then The heat is heated to 25-60 ° C from the bottom, A, a series with cooling at 30-90 ° C below A, until the temperature is fully equalized throughout the volume and heated from the heating temperature.

The method is dried as follows.

Claims (1)

The billet of the manufactured product is heated to austenization temperature, plastically deformed with the formation of the product, immediately cooled (for example, in flowing air) to a temperature of 30 - 90 ° C below A., then repeatedly heated to 25-60 C above A., a series with cooling at 30-90 ° C below A, until the temperature is completely flattened by sceviy volume, quenched from the heating temperature and tempering is performed for hardness, which provides mechanical processing. After removing the stamping allowances by machining, the product is finally quenched and released to a predetermined hardness. At meer. In the manufacture of a bimetallic die insert for stamping the MAZ-2OO half-axle gear with a 210 mm tooth billet and 71 mm height, the plaster layer of which is 5 mm thick from 3X2V9F steel and the base from 7X3 steel is heated to 1150-1200 C, is deformed plastically forming the insert, immediately cooled with flowing air to 660-640 С on the surface, then heated 4 times to 74О-760 С in the top of the bone layer, alternating with cooling to 660-640 ° С. Then, from 740–760 ° C, the strain insert is quenched into oil and released at 65 ° C, which ensures that the hardness of the cladding layer is equal to X 34-38, and that of the base is HRC 28-30. By machining, stamping allowances are removed, the die insert is heated to 1050 ° C in oil, and tempering is done at 54 ° C. After such heat treatment, only an engraving is polished. The hardness of the cladding layer before operation is equal to PKS 54-56, and the fundamentals - HRC 42-4. The use of thermal cycling during cooling from strain heating allows to carry out insertion quenching from a temperature of 740-760 ° C. Production tests showed that serial die bimetallic inlays , manufactured by the proposed method, were worn out after erasing after 4000 forgings. Such thermocyclic cooling from deformation heating, which prevents phase hardening, the precipitation of carbides at grain boundaries, retains the properties of austenite obtained during the hot hardening process and ensures that quenching is maintained from a temperature below the end of the deformation and the product is the same throughout the volume. Using the proposed method prevents warping and cracking in the process of thermomechanical treatment; increases the structural strength of the product and its durability; enables the manufacture of thermomechanical products from high-alloy steels and the form of the mold: intensifies production and thereby increases the productivity of work. The invention The method of hardening products, including heating the workpiece to the austenization temperature, plastic deformation, quenching, tempering, machining, final quenching and tempering, characterized in that, in order to prevent distortion, after deformation the product is repeatedly cooled to a temperature of 30-90 ° C is lower than A and heated to a temperature 25-60 C higher than the full temperature equalization throughout the volume and from the heating temperature quenched. Sources of information, taken into account in the examination. 1, A. Assonov. Basic information on metallurgy and heat treatment, 1972, pp. 93-94. 2, Novikov I. I. Theory of heat treatment of metals, M. 1974, p. 398-392.