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about the product TAKAMAZ a variety of machine tools.
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The 7th STAINLESS STEEL SUS304
HIGH-SPEED FINISH CUTTING

Stainless steel, once
considered a hard-to-cut
material, can now beprocessed stably inmass-production fields
thanks to abundant cutting
data and dedicated tools.
However, not many technical data relevant tohigh-speed cutting of stainless steel have been
disclosed and many feel difficulty in switchingto mass-production.Here we will introduce
high-speed finish cutting of stainless steel
SUS304, which is used widely among various
stainless steel materials, as an example.

Experiment 3: Solution for Generationof Localized Flank Wear
Tool: CNGG120408 VP10RT
Cutting conditions:Cutting speed 400 m/min,Cutting distance 12 km,
Cutting time 30 min,feed rate 0.12 mm/rev,
depth of cut 0.1 to 0.8 mm

Experiment 1: Checking Propagation of Wear
Tool: CNMG120408, equivalent to M25
Cutting conditions:Cutting speed 250 m/min,cutting distance 6 km,
cutting time 15 min,feed rate 0.12 mm/rev, depth of cut 0.4 m
Supposedly due to use of
a broadly applicable material,coating is flaked causing
considerable wear on the flank.
We also found that setting
the cutting speed a little
higher significantly propagateswear.

Experiment 2: Finding the Suitable Toolfor High-speed Cutting

Boundry of cutting area
(width with raried cut of depth)

Experiment 2 proved that
localized flank wear has
critical influence at acutting speed of 400 to
500 m/min. Experiment
3 was conducted to checkthe effects when the depthof cut is variable in

the range of 0.1 to 0.8 mm.At a cutting speedof 400 m/min,generation of localized flank wear
was suppressed and tool damage was very small
proving that varying the depth of cut is aneffective solution.The reason for this issimply the fact that the boundary position on
tool nose is changing.However, the effect was
not achieved at a cutting speed of 500 m/min.

Transition of Surface Roughness and Flank Wear
With a tool equivalent to M25 for which wearon the minor flank is observed, surface roughnesslevel also changed significantly as the cutting
distance increased, showing the same tendency as
in general high-speed stainless steel cutting.

Tool: CNGG120408 VP10RT
Cutting conditions:Cutting speed 300, 400 to 500 m/min,cutting distance 12 km,
cutting time 30 min,feed rate 0.12 mm/rev,
depth of cut 0.4 mm
At the cutting speed of300 m/min, nominal chippingdeveloped at the boundary of
the cutting area when cutting
Boundary of cutting area distance reached 3 km.
However, propagation ofchipping is not discerned
after that and even at cutting
distance of 12 km, flaking on the face is notobserved and only small wear and deposits were
found at the nose section.The condition of
the corner did not change much from that ofa new insert.
Selection of VP10RT, the heat-resistant steel
material with sharp cutting performance, andsetting the depth of cut to half of the noseradius for suppressing localized flank wear
may have lead to the good results. In one
reference document, a case where localizedflank wear was successfully suppressed by
setting the side cutting edge angle larger
than 45 degrees was introduced. However, thetool broke after a cutting distance of 8 km
at cutting speeds of 400 to 500 m/min due tolocalized flank wear and flaking on the face.

Conclusion
With VP10RT, stable results were obtained in both
surface roughness and width of wear area.
Accordingly it is assumed that this tool can beused for finish cutting in mass-production ofstainless steel parts at a cutting speed of
300 m/min. Previously, we introduced pure ironcutting and in that article we reported the optimum
cutting speed was proved to be 300 m/min.
Taking the past test results and the current test
results into consideration, it is most likelythat some factor is affecting the finish cuttingzone at a cutting speed of 300 m/min.
In zones where depth of cut is large, cutting witha variable depth of cut is effective. From theresults obtained in this test, solving
the localized flank wear problem is considered
the most significant topic and we expect further
improvements of cutting tools.