SU1604166A3 - Cermet high-melting wafer - Google Patents

Abstract

This invention is a carbide rod for rock drilling and mineral cutting. Because the rods are built of a core of carbide containing etaphase surrounded by an outer zone of etaphase-free carbide, they have increased strength and an extended service life during practical usage.

Description

The invention relates to metal-ceramic carbide inserts, preferably used in rock drilling tools for minerals.

The aim of the invention is to improve the wear resistance of the plate.

The proposed metal-ceramic carbide plate consists of a core and a surface layer of hard alloy tungsten carbide — cobalt, and a hard alloy based on tungsten carbide with 6–15% cobalt containing 15–35% of this phase with a grain size of 2–4 µm, the surface layer is made of a width of 2-3.5 mm from the inner and outer zones with content. 9-22% cobalt in the inner zone and the content of 3-10% cobalt in the outer zone with a width of the outer zone of 0.5-2 mm.

The invention is illustrated by the following examples.

Example 1. Of tungsten carbide powder containing 6% cobal-. One with a 0.3% substoichiometric carbon content (5.5% carbon instead of 5.8% carbon for a full cermet hard alloy) was obtained by pressing disk plates 16 mm high and 10 mm in diameter. The plates were pre-sintered in nitrogen atmosphere for an hour at 900 and then subjected to standard speco

O5

 CH

Lania during this time the plates were rarely packed in fine powder 3 in graphite boxes and heat treated in a carburizing atmosphere for 2 hours at 1450 ° C in a pusher-type furnace. At the initial stage of sintering, the structure of the alpha-beta phase was formed, in which the fine-grained eta-phase was evenly distributed. At the same time, a very narrow zone of the alpha-beta structure, formed on the surface of the plates, because carbon begins to diffuse in the plates and turns this phase into the alpha-beta phase. After sintering for 2 hours, a sufficient amount of carbon diffuses, which transforms the entire eta phase in the wide surface zone. Plas

-, s 41664

outer zone width of about 0.5 mm 3%, and 12% in the inner.

WC-Co alloy structure without phase phase.

The structure of WC-Co without this phase, but more finely ground with a particle size of about 1.8 microns.

Test procedure. With these drill bits, several rows of holes were drilled, seven holes in a row to a depth of 5 m, and then moved to create exact conditions for drilling. When the plate was damaged for the first time, the drill bits were immediately removed from the test and the number of meters drilled was noted (see Table 5)

Table 1

t5

After sintering, the tins produced by this method had a 2 mm surface zone, free from this phase and a core with a diameter of 6 mm, containing about 25% of the finely distributed this phase with a grain size of about 2 mm. The cobalt content on the surface was 4.8%, and outside this phase, 10.1%. The width of the part having a low cobalt content was, for example, 1 mm.

Example 2o Poroda.- solid abrasive granite with a small amount of leptite compressive strength 2800-3100 bar. The machine is a hydraulic drilling machine for a yellow coring hammer. Feed pressure 85 bar, rotating pressure 45 bar, rpm 200 rpm.

Drill columns: 45 mm disk crowns, 2 feathers with 10 mm peripheral plates 16 mm high, 10 drill crowns for each option. The composition of the hard alloy: 94% KS and 6% cobalt. The grain size (samples 1-3) is 2.5 microns.

Test samples with this phase The core contains 20 vol.% Of this phase with a grain size of 2–3 µm, 6 mm in diameter, the surface layer is 2 mm wide, and the cobalt content in the outer zone is about 1 mm 4% and in the inner ten%.

The core contains about 35 vol.% Of this phase with a grain size of 2-3 mm, the surface layer 1.25 mm wide containing cobalt in

 The best sample of an alloy with a phase-phase showed approximately 40% longer service life than the best grade of a conventional hard metal.

Example 3. Abrasive granite having a compressive strength of approximately 2000 bar. The machine is pneumatic equipment with a tracked drive for drilling in the rock of a descending hole. Air pressure 18 bar, 40 rpm. Drill bits — 165 mm drill bits for drilling a descending hole, having plates with a diameter of 14 mm, height

24 mm, 5 drill bits for each option. The interval between dressing of the drill bit is 42 m. The depth of the spike is 21 m. The composition of the cermet hard alloy is the same as in Example 2.

All alloy samples had a grain size of 2.5 microns „

Test specimens.

Sample 1 contains a core with a 1.6 mm bottom with a 30-35% eta-phase with

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a grain size of 2-3 μm and a surface layer containing cobalt in the outer zone 1.5 mm wide 3.5% and 10.5% in the inner zone

Common grades of alloy for comparison. Alloy 2 of tungsten carbide and cobalt without this phase. Alloy 3 of tungsten carbide and cobalt without this phase, fine-grained with a grain size of 1.8 microns.

The tests were carried out at each reshape of the drill bit, i.e. after each second hole, the order of the drill bits was changed so that the same drilling conditions were maintained. The drilling was stopped for each drill bit when the diameter wear became too large or when damage to the plate was visible (Table 2).

table 2

Number of meters drilled

Hardness before drilling

1 2 3

820 100 1560 1390 1520 573 70 1420 1420 1415 429 52 1520 1520 1515

Example

.2

4. Without heating, 500 m of asphalt were cut from a medium abrasive type to a highly abrasive type. Air Temperature Three options were tested.

Machine - road plow four-wheel machine with hydraulic drive and automatic adjustment of the depth of cut.

The blade shaft is 2 m wide, diameter including tools, 950 mm, circumferential speed 3.8 m / s, depth of cut 40 mm.

The equipment — 166 tools were evenly distributed around the shaft (cylinder), of which 60 tools (20 for each variant) had the usual cermet hard alloy 1 and 2 and the proposed hard alloy. The test tools worked in pairs at the same time and were evenly distributed around the shaft across its entire width (see table 3).

66

Table 3

Normal grade alloy9.5

Common grade of alloy8

Alloy containing about 30% by volume of eta phase with a grain size of 2-3 μm9.5

106 20

20

The cobalt content in the outer zone with a width of about 1 mm is 4%, and in the inner one is about 9%.

All plates had a height of 1.7 mm and a diameter of 16 mm.

After the test plate or conventional plate was damaged, the instrument was immediately replaced with a standard one. The amount of wear of the samples is shown in table. four.

Table 4

35

40

45

0

five

From table 4, it follows that the proposed plate is intact.

Example 5: Test site - open pit drilling with roller cone heads (three conical drill bits). Feed force 40 t at 70 rpm. Boreholes were drilled to a depth of 10-17 m. Burov crown - twelve 1/4 of the cone drill bits, two crowns for each option. The breed is mostly empty rock with areas of quartz, compressive strength of 1350-1600 kilo pounds / cm.

Samples tested.

Standard alloy 1 contains 10% cobalt, a plate with a diameter of 14 mm and a height of 21 mm.

Alloy 2 contains 15 vol.% Of this phase with a grain size of 2-3 mm and 10% cobalt, a plate with a diameter of 14 mm and a height of 2 mm has a 2 mm surface area free from this phase and heart-jq fault from this phase . diameter of 9 mm. The cobalt gradient was 7% in the surface and 15% in the part rich in cobalt. The width of the outer zone was 1.5 mm.

The test results of the plates are presented in tabLo 5

1604166 8

The cobalt content in the outer zone with a width of 1 mm is 10%, and in the inner zone is 22%.

In sharopps with standard plates, 30% of the plates were damaged, whereas in the tested roller cutter, only 5% of plastic were damaged.

Example 7. Wire test on reinforced drill bits with a diameter of 48 mm.

Breed - magnetite is empty rock. Burov machine - Atlas Copco SOR1038ND7. Used a hammer drill. Cutting plate:

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height 21 mm, shchirin 13 mm, length 17 mmo Grade of metal-ceramic hard alloy: 11% cobalt and the rest tungsten carbide with a grain size of 4 microns.

Table 5

1220 1750

100,140

13 16

100 123

As follows from the table. 5, the plates of the alloy of the proposed composition have a longer service life, as well as a higher drilling rate.

Example 6. In drilling machines, carbide-coated cutters are used. Plates of alloy having a core of phase to phase have been tested on a drill head (7 feet).

Breed - gneiss, compressive strength 267. MPa, wear-resistant. Drilling length 149.5 m, drilling speed 0.8 m / h

One roller cutter was provided with plates with a diameter of 22 mm and a height of 30 mm from a standard alloy containing 15% cobalt and the rest tungsten carbide with a grain size of 2 μm. The test roller, placed diametrically on the drill head, was supplied with plates having a core with a content of 20 vol% with a size of 3 m by 2–3 mm of the composition; 15% cobalt, tungsten carbide with a grain size of 2 microns.

The surface layer is 3 mm wide, the core diameter of this phase is 16 mm

Breed - magnetite is empty rock. Burov machine - Atlas Copco SOR1038ND7. Used a hammer drill. Cutting plate:

height 21 mm, shchirin 13 mm, length 17 mmo Grade of metal-ceramic hard alloy: 11% cobalt and the rest tungsten carbide with a grain size of 4 microns.

Sample 1 is a core with a content of 25% obo eta phase with a grain size of 3-4 μm and a surface layer 3 mm wide with a cobalt content in the inner zone about 1 mm 15% wide and in the outer 8%

Sample 2 is standard.

The test results are presented in Table 6.

Table 6

As follows from the table. 6, the proposed plate provides longer service life and less wear.

Claims (1)

Invention Formula A metal-ceramic carbide plate is preferable for drilling over rock and excavation of minerals, consisting of a core and a surface layer of a hard alloy tungsten carbide cobalt, characterized in that, in order to increase wear resistance of the plate, the core is 1.7-16 mm in diameter hard carbide based alloy . 160416610 tungsten with 6-15% cobalt, containing and outer zones with a content of 9-22% J5-35% of this phase with grain-cobalt size in the inner zone is 2-4 microns, the surface layer is 3-10% cobalt and the outer layer is filled with a width of 2-3.5 mm from the inner P width of the outer zone 0 5-2 mm.