[Vaibhav.Shelke]

Hello guys
We are thinking to start Hard part turnning on PUMA 400
Has anybody tried earlier?
Can anybody give me more info. about hard turning?

[g-codeguy]

One word. Ceramics.

[fixitpablo]

Kyon work well.
Fiber imbedded ceramics if you need high strength.

[g-codeguy]

Start out with shallow DOCs and slower feedrates...around F.005 for ceramics. Either run dry or make sure there is plenty of coolant on the insert. We run dry.

[Vaibhav.Shelke]

Thank you for your valuable info.
I am happy to tell you that we have succesfully turned components of 62 HRC hardness within 0.006-0.008 mm tolerance range.
But there is a small problem we are facing.
Microstructure looks slightly reddish.
Any suggestions?

[g-codeguy]

Sorry. Can't help you with that. Never noticed anything like that with the few parts we have run. Only job we run on a regular basis is from 52100. Just out of curiosity, what material are you running? Maybe someone else will have an answer for you.

[Vaibhav.Shelke]

Material is 16MnCr5

[g-codeguy]

LOL. Couldn't guess off the top of my head what material those numbers relate to. Not at work, so I couldn't check them against materials I am familiar with.

[Vaibhav.Shelke]

16MnCr5 means Carbon steel with 0.16 % carbon,5 % mangnese and 5 % cromium.It's designated according to Beuro Indian Standards(BIS).

[g-codeguy]

That much I could figure out. Still doesn't help me. What does it equate to in America? 4340, 4140, 1215, BG42, 52100, 8620, 1117, 4350, 1018, O1, D2, etc., etc. Sorry, but I forgot to try and look it up today. Had a day off yesterday to spend with my grandsons. Maybe I'll remember tomorrow.

[syamin]

This are very hard SS steels, so machine slowly unless there are a lot of steps or holes, start with high speeds and decrease as much to avoid overheating but not that much that you early break the Inserts.

DO NOT USE CARBIDE INSERTS, LOOK FOR COBALT OR CERAMIC, I would advise to use Toshiba, You may use high feeds but Ar or deepness should be shallow as to produce hairly like continuous wire burr. Watch out for the angle of insert, use 1mm radius or less.

Ceramic inserts do not need coolant, thermal shock destroys them, cool with cool air.

Santiago Yamin,

Mexican Aerospace Components.