SU1421455A1 - Method of producing articles from pulverulent low-alloyed steels - Google Patents

Abstract

The invention relates to powder metallurgy, in particular to methods for producing articles from powders of low alloy steels, and can be used in the tractor and automotive industries. The purpose of the invention is to increase the density of the surface layer of the product and reduce the energy intensity of the process. The method includes preparation, and their pressing, pressing, sintering, heating, plastic deformation and heat treatment. Plastic deformation is carried out at a temperature of 700-740 ° C with a deformation rate of i 10-sec-. 1 tab. CL

Description

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The invention relates to powder metallurgy, in particular, to methods for producing articles from powders of low alloy steels and can be used in the tractor and automotive industries.

The purpose of the invention is to increase the density of the surface layer of the product and reduce the energy intensity of the process.

with boundary and beyond the boundary values of temperature and rate of plastic deformation and the known (basic) method, as well as comparative values of the density of the surface layer, the relative energy consumption of technological processes. These data show that high values of the final density of the surface layer (99.6-99.9%) and low values of energy consumption (0.042-0.047) are achieved at the temperature method includes the preparation of the charge, ° deformation 700, 720 and 740 ° C and

x growth 10 and 5-10 s.

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pressing, sintering, heating, plastic deformation and heat treatment.

Plastic deformation occurs at 700–740 ° C at a rate of 10 sec.

The mixture of iron metal powders, alloying additives and graphite is mixed in proportion to obtain structural steel of a given chemical composition, with an addition of 0.5 wt.% Zinc stearate, pressed billet with a force of 500-750 MPa, sintered in an atmosphere of dissociated ammonia for b- 8 hours, interfere with a stamp, undergo plastic deformation under isothermal conditions at 700-740 ° C at a rate of 25 10, and final heat treatment is carried out.

Example. Make an adapter with an outer diameter of 25 mm, internal diameters of 12 and 6.5 mm and a height of 16 mm of powder steel 40X.30

A mixture of iron powders ПЖЗМЗ, ПХ13М2 stainless steel, pencil graphite and 0.5 wt.% Zinc stearate is mixed, pressed with a pressure of 500 MPa, baked in an atmosphere of dissociated ammonia at 1250 ° С for 6 h, deformed under isothermal conditions. x at 720 ° C at a rate of 5-10, quenching and tempering are carried out in the standard mode.

The table shows data on the technological modes of the proposed method

Thus, the optimum process mode, which allows to obtain a surface layer density of 99.9% and relative energy consumption of 0.046, is the following mode: deformation temperature of 720 ° C, deformation rate of 5-10.

Compared with the known method, in which the density of the surface layer is equal to 96.7%, and the specific energy consumption is 0.060, the powder parts obtained by the proposed method have a relative density of 3.2% more, and the energy consumption of the surface layer is lower by 23, 3%.

The proposed method is simple to implement and specialized equipment is not required for its introduction into production.

Claims (1)

Invention Formula The method of obtaining products from powder alloyed steels, including preparation of the charge, pressing, sintering, heating, plastic deformation and heat treatment, characterized in that, in order to increase the density of the surface layer of the product and reduce the energy intensity of the process, plastic deformation is carried out at 700 -740 ° C with a strain rate of 10 -10-2 -1 with boundary and beyond the boundary values of temperature and rate of plastic deformation and the known (basic) method, as well as comparative values of the density of the surface layer, the relative energy consumption of technological processes. These data show that high values of the final density of the surface layer (99.6-99.9%) and low values of energy consumption (0.042-0.047) are achieved at deformation temperatures of 700, 720 and 740 ° C and x growth 10 and 5-10 s. five 0 five Thus, the optimum process mode, which allows to obtain a surface layer density of 99.9% and relative energy consumption of 0.046, is the following mode: deformation temperature of 720 ° C, deformation rate of 5-10. Compared with the known method, in which the density of the surface layer is equal to 96.7%, and the specific energy consumption is 0.060, the powder parts obtained by the proposed method have a relative density of 3.2% more, and the energy consumption of the surface layer is lower by 23, 3%. The proposed method is simple to implement and specialized equipment is not required for its introduction into production. Invention Formula The method of obtaining products from powder alloyed steels, including preparation of the charge, pressing, sintering, heating, plastic deformation and heat treatment, characterized in that, in order to increase the density of the surface layer of the product and reduce the energy intensity of the process, plastic deformation is carried out at 700 -740 ° C with a strain rate of 10 -10-2 -1