Share your machining strategies

[Müřlıń®]

I machine alot of large cavities in steel with a high Nickle content. It's tough and around 42-45 RC. Hand polishing the impressions with a die grinder is required. I do not use polishing stones for this. So I am not trying to get critical with finish. Prol around 32 RMS, give or take a few.

 

For finishing, a .250 ball @.01 stepover works well on most areas. On hard to polish areas using a .125 or smaller ball, a .003-.005 stepover is required. (I only have 10 IPM for finishing, old machine).

 

Rough Pocket, Finish Contour,

Finish Scallop, Finish Shallow, Finish Leftover and Finish Pencil Work best for my application.

Sometimes Finish Paralell, but it is rare.

 

 

Iscar tools work best for me. I like the positive rake, and on all the ball endmill inserts, hand sharpening on the face of the cutting edge with a diamond wheel allows for more use out of the inserts when roughing.

 

 

Murlin

 

[ 07-12-2003, 12:52 PM: Message edited by: Murlin ]

[mold100]

I am cutting 52 rc h-13 as I type this with a 6mm

ball at 28,000 rpms 190 ipm with a .002 step down and .006 step over.The only thing bad is I programmed it with surfscam.

 

run it till breaks and back off 10%

[skeetboy25]

in the olden days ferric nickle alloys were refered to as "super alloys" there is a reason for this.

[Müřlıń®]

***holds hand cupped to ear and listens carefully

 

Murlin

[Guest CNC Apps Guy 1]

quote:

---

in the olden days ferric nickle alloys were refered to as "super alloys" there is a reason for this.

---

You ain't kiddin'. Any of those high nickel alloys we would call them "nastyloy". Though with tooling what it is today, CBN, Ceramic, Cermet, just to name a few makes it a little more machinable and economical to cut. For example Inconel 718 (I think) machines around 20 SFM using HSS. With some of the exotic tooling out there today can take it to near triple digits depending on workholding, HP, process, etc...

 

The first metal I ever cutwas Titanium so what I cut now (99% Aluminum) is like cutting butter with a hot knife.

 

JM2C

[Müřlıń®]

James.....I havent tried to machine my dies with any ceramic tools yet....

 

Currently the YG coated fine grade carbide from Korea, does an outstanding job for me. 20 bucks for a 1/4" ball 2-flute, not too pricey either.

 

 

Murlin

[Allan]

Super alloys have applications in aeronautics, space, nuclear, chemical, and petrochemical, power generation and furnace industries, where extreme temperatures, mechanical stresses and corrosive environments are encountered.

 

There are three types of steels that are referred to as super alloys:

 

Nickel-base - Inconel, Incoloy, Hastelloy and Nimonic

 

Cobalt-base - Stellite, M2, M42

 

Iron-base -A236, 17-4 PH (this stuff is actually shinny coloured rock)

 

"Ferric" chloride is what is used to do etching on these for grain analysis the Nital (Nitric acid) will not etch these.

 

 

HTH

[Guest CNC Apps Guy 1]

Yum!!!!!

[Müřlıń®]

Allen......ooooo Stellite #6....I use this for heliarcing a hardface around trim-punch dies made out of low carbon steel.

 

Its cheaper to do that, rather than using a whole piece of toolsteel and temper it....

 

Hrmmmm.......almost out of it too.....$40 a LB. I wait till the last second to buy a box of that stuff:)

 

I'm not sure what the exact Nickle content of the Die-steel my customer uses, Finkle and Summers keeps it a secret:)

 

They sometimes forge parts made out of Inconel and Monel..... Love it when they do that....

the dies dont last very long......

 

Thats what I call job security....hah

 

 

Murlin

[Müřlıń®]

Bump-o-rama.....

 

 

I really would like to hear from some of you guys with HSMC's..... What kind of strategies do you use??

 

When I win the lottery, I am getting one of those

 

 

Murlin

[Guest CNC Apps Guy 1]

When turning Stellite some 8 years ago, I used Kennametal Kyon series inserts. I'll just say that the term "Hard Turning" is being far too kind, but Kennametal sure made it a bit easier. When you looked inside the machine it was glowing red/orange from the heat. Course you couldn't use coolant (for anything other than keeping the way covers cool with the shower) because if you did the inserts would shatter. MAX RPM, .0015 IPR @ .020 DOC if memory serves. Fun stuff.

[Chris Rizzo]

Brings back memories of a past job about a decade ago...Worked at a forging company turning superalloys- Waspaloy, Hastaloy, Nickel 625, titanium alloys, etc. All forged or rolled seamless rings (donuts), 3"-70" in diameter. On my lunch break it was great watching the crews run the single frame air hammers, and load the big rings with a fork truck on the double frame hammers...

Anyhow, all our machining was on manual machines; (BIG Leblond engines and BIG Bullard verticles). We used a lot of Kenametal inserts, can't recall the model. The metal sure is tough, but try the mill scale from forging! Like trying to machine granite!

[Müřlıń®]

Luckily the only stellite I have to cut is right on the edge of a Trim-punch die that I have heliarc-welded. Use 6%cobalt 1/8 bare stellite rod.......Used to turn the round stuff off, but now I cut all stellite on the mill. Round or square.....its still as hard as it ever was though

 

 

cmr....yes that scale is tuff stuff.....I used to have to turn my nickle alloy out of a raw forged billit that was all scaled up.....

Took alot of inserts and was murder on the ways of my old engine lathe......

 

Murlin

 

[ 07-13-2003, 09:54 PM: Message edited by: Murlin ]

[Keith M]

I had to cut stellite on dies for transvers wedge roll machine. The original dies wore out and they just welded them up. I cut them on a 3 axis mazak mill. That was a lot of fun.

 

[ 07-14-2003, 01:55 PM: Message edited by: Keith M ]

[CAM-mando]

Anyone for some Rene' 80 ?

[Müřlıń®]

Cam thats a new one on me....I been locked in da basement for 20 years and they are just now lettin me out

 

Seriously though, I love learning about new stuff...so do tell........

 

 

Murlin

[mold100]

Cam is it deep red and a plastic or resin?