SU891409A1 - Material for magnetic abrasive working - Google Patents

Description

one

The invention relates to the production of ferromagnetic abrasives, which can be used for magnetically abrasive machining of machine parts and devices.

A known material for magnetic abrasive treatment, containing 20-30 wt.% Of electrocorundum and 70-80 weight. % technical iron and obtained by powder metallurgy methods I.

However, the scarcity of the initial components and the complexity of the technology for producing powder products — dosing and mixing electrocorundum with technical iron, making briquettes and sintering them in a reducing or inert atmosphere, cooling, crushing, grinding and sieving the material to the required grain sizes — limit their production and use during mass magnetic abrasive machining.

In addition, this material does not have a high bond strength between the abrasive and metal parts, which leads to their segregation in the process of transporting and processing parts.

There is also known a method for producing electrocorundum materials, including

selective reduction of iron oxides, silicon and partly titanium in high-power electric furnaces from alumina-containing raw materials, melt production into a lined mold, cooling, crushing, enrichment and sieving of grinding grain 2.

 However, to reduce the content of metallic impurities that have not settled on the furnace hearth during smelting, the crushed alumina is subjected to multistep magnetic separation. In addition, some products

The Q magnetic segregation of electrocorundum is used in small quantities for tamping blast furnace chutes, but mostly they are sent to the dump.

The purpose of the invention is to simplify the production technology and reduce the cost of material.

Claims (2)

The goal has been achieved by using ferrous electrocorundum waste produced as a result of magnetic separation of smelted 20 in an electric furnace, crystallized and crushed electrocorundum, as a material for magnetic abrasive treatment. The use of ferrous production of electrocorundum as materials for magnetic abrasive processing is possible due to their high cutting and polishing properties, self-sharpening, with sufficient magnetic permeability for reliable retention of parts by a magnetic floor in the working gap. Almost every grain of material with a grain size of 1250-Omkm contains a ferromagnetic inclusion, which is a high-silicon cast iron of composition, weight. %: Si 9-12; Recome81-86; Ti 1.7-2.0, A1 0.9-2.0; Р 0,25-0,35; S 0.030-0.040; Mp 0.2-0.4; From 1.0-1.9. The material is characterized by a high strength of the connection between the abrasive and ferromagnetic parts, since it is obtained as a result of electric smelting and co-crystallization of liquid electrocorundum and cast iron, i.e. there is a mutual penetration of the companions. This prevents segregation of the material during transportation and loading into the working gap of the machine. The use of W-ferrous electrocorundum production in magnetically abrasive processing is also due to the fact that the material obtained as a result of crushing, including its ferromagnetic part, has a highly developed micro- and submicrorelief, high brittleness of both sotavah parts, which improve the self-sharpening of the grains, and therefore abrasive cutting intensity. The high self-sharpening of the material provides a comparative stability of the contact point of the cutting part of a single grain on the surface of the workpiece and, thus, prevents the growth of deformation stresses in the surface metal layer. This allows the material to be used for magnetically abrasive machining of parts whose material does not allow for the occurrence of stress. The microhardness of the abrasive part of the material determined on the PMT-3 device is 2180-2200 kg / mm, and the ferromagnetic part is 1400-1500 kg / mm2. This combination of microhardness of the component grains of the material, as well as the presence of its ferromagnetic part high abrasive properties, allows the process of magnetic abrasive polishing with high speed. In this case, the ferromagnetic part of the grains, in addition to retaining the material in the working gap, participates in the dispersion of the metal — cutting off the microprotrusions and polishing. Gelatous waste from the production of normal electrocorundum in magnetically abrasive machining of parts as compared with the known material provides higher processing performance. The invention allows to significantly reduce the cost and simplify the production technology of powder-like products. In addition, it provides the possibility of magnetically abrasive cutting at high speed, provides the possibility of magnetically abrasive machining of parts that prevent deformation stresses in the surface layer, and reduces unproductive material losses during processing. Claims of application The use of ferrous electrocorundum wastes produced as a result of magnetic separation of crystallized and crushed electrocorundum smelted in electric furnaces as materials for magnetically abrasive machining of parts. Sources of information taken into account during the examination . B 24 D 3/06, 1968. 2.Gasik MI, and others. Electric smelting of aluminosilicates. M., “Metallurgists, 1971, p. 118 and 267.