SU1761778A1 - Glass lubricant for hot plastic metal working - Google Patents

Abstract

The essence of the invention lubricant contains silicon oxide 25-30% calcium oxide 30.5-38%, magnesium oxide 2.3-5.0%, aluminum oxide 4-8%, potassium oxide 0.01-3.0%, oxide boron 5-10%, manganese oxide 0.1-2.4%, ferrous iron oxide 0.05-2.5%, ferric iron oxide 10-20 and sulfur 0.05-4.09%. 2 tab.

Description

The invention relates to the processing of metals by pressure, in particular glass lubricants, and can be used for the manufacture of lubricating washers on a matrix during hot pressing of pipes and profiles of various steels and alloys on hydraulic presses in the temperature range of 1000-1250 ° C.

Known glass lubricants containing oxides of various metals, wt.%:

1. Silicon oxide 50-58; alumina up to 15; boron oxide to 10; calcium oxide or barium oxide up to 25; sodium oxide or potassium oxide 0.5-6.

2. Silicon oxide 45-55; aluminum oxide 5-20; potassium oxide 5-25; zinc oxide 3-40.

3. Aluminum oxide 5.5-7.5; calcium oxide 0.5-6.5; magnesium oxide 0.5-3.5; sodium oxide 27-30; ferric oxide 3.5-5.5; silicon oxide 100.

A common drawback of these glass lubricants is their low viscosity (up to 80 Pa-s) at pressures above 1150 ° C and, consequently, the formation of an excess of the liquid phase in the deformation zone and the resulting deterioration in the quality of the surface of the extruded products.

The closest in composition to the components proposed is a glass lubricant for hot pressing of metals, containing, in wt.%: Silicon oxide 58-67; aluminum oxide 0-8; calcium oxide 13-22; magnesium oxide 7-13; boron oxide 0-5; potassium oxide 0-5; lithium oxide 0-4; sodium oxide 0-7.

However, this lubricant, at pressures below 1200 ° C, has a high viscosity (over 300 Pa-C) and a high softening start temperature, as a result of which an uneven thick layer forms on the surface of the product to be pressed, resulting in scratches,

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scuffing and, consequently, deterioration of surface quality.

The aim of the invention is to improve the surface quality of the extruded products.

. The essence of the invention is that glass lubricant is known, which contains oxides of iron, calcium, magnesium, aluminum, potassium and boron, and additionally contains oxides of manganese, ferrous iron, ferric iron and sulfur in the following ratio of components, mns,%: silica 25-30

Calcium Oxide 30.5-38.0

Magnesium Oxide 2.5-5.0

Alumina 4-8

Potassium Oxide 0.01-3.00

Boron oxide5-10

Manganese Oxide 0.1-2.4

Ferrous oxide of ferrous oxide, 05-2.50. Ferric oxide of ferric oxide 10-20 Sulfur 0.05-4.09 Raw materials were used to prepare glass lubricants according to the following State Standards:

silica was injected with quartz sand GOST 222551-77; calcium oxide - chalk GOST 17498-72; magnesium oxide - GOST 4526-75; alumina - alumina GOST 6912-64; potassium oxide - potash GOST 10690-73; boron oxide, organic acid GOST 18704-78; manganese oxide TU 14-9-54-73; iron oxides GOST 8136-74, sulfur TU MHP ORU 83-67,

Raw materials were pre-dried to a moisture content of not more than 2%, crushed to a fraction of 0.5 mm and thoroughly mixed.

Glass grease was boiled in alundum crucibles in silicon lechi at a temperature of 1400 ° C for 1 h. With a satisfactory test on the thread, glass grease was poured onto a metal plate. After cooling, the glass lubricant was crushed to a fraction of 0.8 mm. Washers of a thickness of 10–20 mm with an outer diameter, 5–10 mm smaller diameter of the container hub, and an inner diameter, 10% larger than the diameter of the die aperture were made from a glass fiber powder. Were manufactured and tested formulations steklosmzzki. presented in table.1.

Testing of glass lubricants was carried out according to the existing technology for pressing pipes of size 89x9 mm made of steel 12X18H10T on a horizontal hydraulic press with a force of 3150 tons. The test results are shown in Table 2.

It is known from the literature that the viscosity of glass lubricants used for the matrix should be in the range of 70-110 La. The viscosity of the proposed glass lubricant (compositions 1, 2, 3) is in the named range, and the difference between the temperature of the beginning of softening and the spreading temperature of these lubricants is 30 ° C, which allows to obtain pipes of satisfactory quality.

A known glass lubricant has a viscosity of 280 Pa-s, a high softening start temperature (1180 ° C) and a narrow interval between the softening start temperature and the spread temperature (20 ° C), resulting in the formation of scuffs along the entire length of the extruded tubes, therefore the quality of the outer surface of the compression pipes deteriorates,

Thus, the use of the proposed glass lubricant ensures that the outer surface of the pressed products is of high quality by eliminating scratches and scratches.

Claims (1)

Glass ointment for hot metal forming, containing oxides of silicon, calcium, magnesium, aluminum, potassium and boron, characterized in that, in order to improve the surface quality of the extruded products, it additionally contains ferric manganese, ferrous iron oxides and sulfur with the following ratio of components, wt.%: Silicon oxide 25-30 Calcium Oxide 30.5-38.0 Magnesium oxide 2.3-5.0 Alumina 4-8 Potassium Oxide 0.01-3.00 Boron oxide5-10 Manganese Oxide 0.1-2.4 Ferrous oxide bivalent0, 05-2.50 Ferric oxide trivalent10-20 Sulfur 0.05-4.09 Table 1 The compositions of the proposed and known steklosmezok for hot processing metals Note. 1,2,3 — suggested lubricants with limiting values; 4-known lubricant. The results of the comparative tests of the proposed and well-known Stekg-ss: - - ezok for hot metal forming Ta5l-ltsa2