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METALWORKING EQUIPMENT AND TOOLS

The RPI with the designation SNMN 12 04 08-FR was mechanically
fixed in the holders of turning tools. Plates in accordance with GOST
25426-90 with the designation 6739 were soldered to the holders
in accordance with GOST 18879-73. As a result, two types of
brazed lathe cutters were manufactured with dimensions
according to GOST 18879-73:
a) with plates obtained by SPS;
b) with standard VK6 alloy plates.
The cutters had the following geometry of the
cutting part: φ = 90°, φ1 = 7°, γ = 10°, λ = 0°, α =
10°. In the course of the tests, billets were turned:
a) cylindrical for longitudinal turning 450 mm
long from rolled products with a diameter of 220
mm made of steel 45 in accordance with GOST
1050-68 in the state of delivery with a hardness H B
180, pre-machined to a diameter of 205 mm; b) a special shape with a hole for
turning on an annular end with a diameter of 34 to 88 mm from cast iron СЧ20
in accordance with GOST 1412-85 with a hardness of HB 160.

Turning a cylindrical billet without coolant observed. In general, it can be considered
supply was carried out in the following modes: V that both inserts showed the same cutting
= 150 m / min; s = 0.05 mm / rev; t = 1.0 mm. ability in face turning of SCH20 cast iron.
The RPIs obtained by the SPS were divided into The test results are shown in Figure 1.
groups and marked according to the sintering
temperature of the billet. Out of 4 RPIs in each
group, three were randomly selected. For testing,
the RPI was arbitrarily set on one of the cutting
edges. The processing was carried out for 3
minutes, after which the RPI was removed,
the wear was measured, and then fixed
again by turning it 90 degrees to replace the
cutting edge. Each of the three RPIs in the
group was tested on three cutting edges.
Turning of a billet made of steel 45 was also sintering temperatures
carried out with brazed cutters.
Measurement of the amount of wear
along the back surface was performed
on a universal stereomicroscope SteREO
Discovery V12, designed for volumetric Wear on the flank, mm
observation of small objects with a Fig. 1. Wear on the flank of the cutting part of the cutters
simultaneous magnification and hardware when turning 45 different plates obtained at different
resolution of 2452x2056 points. sintering temperatures: 1 - turning by replaceable square
plates; 2 - turning with a brazed plate obtained by the SPS;
In the process of face turning of a 3 - turning with a standard brazed plate.
billet made of SCH20 cast iron, the wear of
the plates obtained by theSPS and the wear
of standard plates after 10 passes with a
cutting depth of 0.5 mm, feed 0.2 mm / rev, and a
spindle speed of 400 rpm were determined. When
turning from the hole to the periphery, the cutting
speed increased from 42.7 to 110.5 m / min.
The radius of curvature of the cutting edge
ρ was compared before and after cutting the cast
iron billet. On the cutting edge of the standard
brazed plate, the radius ρ changed from 0.061 mm
to 0.146 mm, and on the brazed plate obtained by
the SPS, from 0.031 mm to 0.118 mm. At the same
time, the nature of the spalling chips was the same
for both inserts and was stable. No build-up was

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