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Super Duplex

infoseeker2020

Plastic
Joined
Feb 12, 2020
Hello, I’m machining 2205 Duplex Stainless and I’m having a hard time finding the best speed and feed to run. I’m facing first then I’m roughing the OD and ID for the next op3. My stock is 12” diameter x 25” OAL x ID 8” diameter. I want to only remove.200 from my OD and I will finish my ID profile (10.626) w/ an 800 rms.
My setup is this…
Im chucking onto the 12” OD of the part with a 4-jaw on a horizontal lathe. I face and apply two bands on for my steady rest, bring in my steady rest and turn my OD then Finish my ID.

I’m running my OD at:
Speed 160 rev
Feed .012
DOC .125

I’m running my ID at:
Speed 325 rev
Feed .015
DOC .100

Man this is kicking my but and any advice/recommendations will be greatly appreciated.
 
What is your problem? Poor tool life? Tool breakage? Cycles to long?

What kind of tooling are you using? High speed steel? Carbide? Inserts?
I’m trying to shorten my cycle time…
To turn down my OD I’m using a CVD-coated DNMG 432 Carbide
On my ID I’m rough and finishing with a 30” sandvik silent-tool bar with a CVD-coated DNMG 432 Carbide
The machine is Puma 5100XLB.
 
Looks like too fast. 500 SFM OD and 680 sfm ID. Why are you turning the ID 35% faster surface speed than the OD? What is the recommended surface speed? You really ought to talk about SFM rather than RPM.
 
Looks like too fast. 500 SFM OD and 680 sfm ID. Why are you turning the ID 35% faster surface speed than the OD? What is the recommended surface speed? You really ought to talk about SFM rather than RPM.
I was way to low on my sfm! (60 - 100) was the range I was in but after some digging, I came across 300 - 400 and feed was .012 - .013 which worked out better as I played around and I was able to complete the job. I just need to get better with my S&F on stainless and other difficult materials. This is the roughing program I used.
 

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I’m running my OD at:
Speed 160 rev
Feed .012
DOC .125

I’m running my ID at:
Speed 325 rev
Feed .015
DOC .100

This is the RPM from your first post. Then above you say 60-100 SFM. This SFM and the RPM don't match. I don't understand. Forgive me, but do you really understand SFM?

Your final program shows 302 SFM and this seems about correct. Glad you completed your job!
 
I'm confused by his posts, too, brew guy. The speeds do not compute.

Infoseeker - knowing you have a CVD coated insert doesn't mean much...grade and chipbreaker is what's important. Just make sure you're using something for SS. You're using a Sandvik silent bar, so I', assuming you may be using Sandvik inserts. Their 2025 grade is an all around great performer in SS and duplex SS. In 316SS I run around 400 sfm, but sometimes jump up to the 2015 grade and run around 450-470 sfm for roughing. Both of those grades are CVD coated. In duplex, I drop about 20% off on those speeds.
The chipbreaker will govern what feeds to use.
 
This is the RPM from your first post. Then above you say 60-100 SFM. This SFM and the RPM don't match. I don't understand. Forgive me, but do you really understand SFM?

Your final program shows 302 SFM and this seems about correct. Glad you completed your job!
Thank bro. It still can be better but the jobs done, error free, that’s good enough for now. That for all the input and assistance.
 








 
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