Ta k a m a z R Y U - G I

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The 14th Rotary Machining of Quenched Steelthrough Compound Machining
Quenched steel is frequently
used in components such as
automotive parts where durability
is demanded, and finishingprocess such as grinding iscommon. For this reason, currently
the efficiency is poor, andthere is an increasing needfor more efficient machining.
We would like to introducethe results of our studies
about the effect of rotary machining and increased
efficiency on quenched carbon steel finishing.

X-axisworkpiece

toolY-axis
10°A Section Details

Direction of Tool Rotation

toolchuckA

Trial Content

Feed direction

workpiece

Figure 1 shows a schematic of the current rotary
machining. Using a compound machine, the material
to be ground is chucked on both sides. The cutting
position is placed at a 10° offset relative to
the Y axis in consideration of the tool shape.
For this reason, the rake angle is -10°, andthe draft angle is 10°. The cutting conditions
are shown in Figure 1. Tool runout is less than
10μm, and the tool life is defined as the 100μm
flank wear width (VB) or the loss state limit.

Trial Result(Verification of the Rotary Machining Effect)
Figure 2 shows the relationship between cutting
distance and flank wear width when a tool is ina state where the rotary tool rotation has been
stopped and fixed (hereafter "non-rotating tool")is used. As shown in the figure, flaking appearedin the non-rotating tool at a cutting distance of0.2km, and the tool reached the end of its life.
On the other hand, the rotary tool had a relatively
small flank wear width of 32.6μm even at a cutting
distance of 1.5km. This is thought to be because
the tool wear is dispersed across the entire cutting
circumference by the rotation of the tool. It isestimated that, in the case of the rotary tool,
the power of the thrust force direction was reducedby the rotary operation of the tool, and therefore
flaking did not occur.
Carbide Coating
Material
And in reality, it was（K10+TiSiN Coating）
Tool
confirmed as a resultSize
φ 10 × 75mm
of having verified
SCM420（HRC60）
MaterialWorkpiece
60 × 500mm
Size
the difference inthrust force to have
Workpiece Rotational Speed
100（Vw m/min）been reduced by about
Tool Rotational Speed
31.4
12% with the rotary（Vt m/min）tool compared toCutting
Feed Rate
Condition
0.1, 0.3, 0.5（f mm/rev）
the non-rotating tool.
Cutting depth（d mm）

0.1

Cutting Method

Up cutting

Cutting Environment

dry machining

Table 1 Cutting Condition

Direction of chuck Rotation

Figure1 Rotary Machining Schematic

Trial Result (Verification of the Effectof Feedrate Increase with High Efficiency)
Figure 3 is a comparison of the draft wear thickness
and the maximum height roughness for a cutting
distance of 1.5km. As shown in the figure, theprogression of the draft wear thickness tends tobecome faster as the feed rate increases.
In addition, the maximum height roughness of the work
surface is shown to be 2.1μmRz under feed rate
conditions of 0.3mm/rev, and the variance is relatively
less. Furthermore, Figure 4 shows the relationshipof the cutting distance and draft wear thickness
under feed rate conditions of 0.3mm/rev. Even at
a cutting distance of 5.0km, the wear thickness
was small at around 40μm, and the progress ofwear was confirmed to be gradual.

1. In rotary machining where the rotation
shaft of the tool is forcibly driven,
the tool gradually wears out, and damage
such as flaking is not observed
2. In the working of quenched carbon steel
by rotary machining, tool wear wasmarkedly inhibited compared to conventional
work methods.
3. In rotary machining, the thrust force isreduced compared to a non-rotating tool
where the rotary tool has been stopped
and fixed.
4. Even if the cutting distance is extended
under feed rate conditions of 0.3mm/rev,
there was no flaking on the cutting lip,
wear progressed gradually, and highefficiency is possible.

Ta k a m a z R Y U - G I

SummaryThus, it was possible to obtain the above effectthrough rotary machining for finishing work on
quenched carbon steel when the effect and efficiency
thereof was verified.

※This paper was a joint undertaking withthe laboratory of Professor Hideharu Katoof the Kanazawa Institute of Technology,Department of Mechanical Engineering.

505.0
Vw : 100m/min
V t : 31.4m/min
d : 0.1mm

Vw : 100m/min
f : 0.1mm/rev
d : 0.1mm

Vt : 0m/min
Vt : 31.4m/min

40: VB: Rz

40

4.030

3.020

2.0

101.0

Draft Wear Thickness VB μm

Draft Wear Thickness VB μm

Flaking30

201000.51.01.52.0Figure 3Frigure 2 Cutting Distance and Draft Wear Thickness
per Various Tool Rotation Speed

100Vw : 100m/min
V t :31.4m/min
d : 0.1mm
f : 0.3mm/rev

8060402001.02.03.0

4.0

5.0

6.0

Cutting Distance L km

Figure 4Relationship of the cutting distance and draft
wear thickness at a feed rate of 0.3mm/rev

0.30.5feed rate f mm/rev

Cutting Distance L km

Draft Wear Thickness VB μm

00.10

Comparison of the draft wear thickness and the maximum
height roughness at a cutting distance of 1.5km.

surface roughness Rz μm50