Turning hardened forged steel with CNC Lathe (OP 1)
by Lathe on Aug.20, 2009, under Lathe Videos
Turning hardened forged steel using CBN insert Read more on my MadLog: madonno.com
Popularity: 3% [?]
No related posts.
25 comments for this entry:
Leave a Reply
-
Welcome to HandLathe.com - Lathe Products and Blog!
Thanks for dropping by! Feel free to join the discussion by leaving comments, and stay updated by subscribing to the Lathe Forum.
Custom Search
August 20th, 2009 on 5:05 pm
Thanks, It looked dangerous but, it’s apparently not so dangerous to be scared of.
Thank for this advise.
August 20th, 2009 on 5:05 pm
Are you a machinist? It’s not dangerous neither for you nor the machine. So it’s better to do what the boss wants you to do
August 20th, 2009 on 5:05 pm
Of course, but in this case it was not dangerous at all. All you can damage is the insert. When you hear it breaking you stop. You should see the parts we machine on the carousel (horizontal) lathe. It looks pretty scary when you see a 1000 lbs block spinning off-center on the table!
The “boss” tells me what needs to be done but I have to figure out myself how to machine the part… so he won’t tell me how to run the machine.
August 20th, 2009 on 5:05 pm
i am a cnc lathe operator
we should obey what boss say
but we should be intelligent enough to dont risk our life and dont breakdown our machine
August 20th, 2009 on 5:05 pm
yea, the chips are just illuminated very brightly. they are very small though. looks like a meteor shower. lol
August 20th, 2009 on 5:05 pm
No, the cutting speed was between 330 (interrupted cut) and 430 ft/min. Feedrate was between 0.003 and 0.004 inch/rev. The diameter of the part was about 7 1/2 inches.
We didn’t have much trouble turning those parts. We just had to tell everybody in the shop who came over to tell us something is wrong that we did not forget to turn on the coolant and the glowing chips are just fine
August 20th, 2009 on 5:05 pm
I could be wrong but you are turning way too fast dia looks like about 6 inch and your feed looks very slow
but good job man keep it up
August 20th, 2009 on 5:05 pm
That is hot!
I’m scared when I see all of these red sparks or pieces of material that does come off.
I don’t do it when i’m orderd to do something like this!
August 20th, 2009 on 5:05 pm
We usually cut dry with Seico rnm 42s 250r cbn 350. G96 S0800 Surface speed at F.008 feed rate. Kennametal DNMA 332 KD200 insert we cut wet G96 S0800 Surface speed @ F.006 Feed Rate. I run a Mori Seiki Sl-65MC with 12 Station Quick Change turret and 3 station live tool.
August 20th, 2009 on 5:05 pm
i think this process is dry hard turning…emerging as one of the substitutes for grinding operations.
August 20th, 2009 on 5:05 pm
I remember Green Leaf’s ceramic inserts. We turned turbine parts made of material called “Waspaloy”.
August 20th, 2009 on 5:05 pm
You should try it with green leaf inserts they are better and a lot cheaper than the kennametal end CBN of iscar. We have a speed (G96) of 480 m/min and a feedrate of 0.13mm/rev on inconel 718, and with stellite 200 m/min and a feedrate of 0.14mm/rev. And with inconel we use coolant (allot! right on the insert!)
August 20th, 2009 on 5:05 pm
No it wasn’t necessary to pull out the chips. They were like soft steel wool. And since it was turning a big radius on the ID it was enough clearance anyway.
August 20th, 2009 on 5:05 pm
I would of used a long stemmed hook to pull those chips off when they were building up. I guess it doesn’t matter much since that’s hardened steel, not something soft like aluminum.
August 20th, 2009 on 5:05 pm
Ever try ShapeMaster Tool?
August 20th, 2009 on 5:05 pm
Have you ever turned hardened steel (intermittent cut) with such an insert? We called it diamond but it’s obviously not (read message above). It’s not recommended to turn the coolant on due to the thermal shock that will crack this type of insert.
August 20th, 2009 on 5:05 pm
get some coolant on there and slow the speed down but increas the feed rate..
August 20th, 2009 on 5:05 pm
Well, I do know that Kennametal gets blown out of the water by Sumitomo in a few instances and it comes down to grade selection and the ability to cover all of the clients needs that way. Kenna doesn’t have the grade range that Sumi does. I don’t have a particular reference though.
August 20th, 2009 on 5:05 pm
Yep. You know a lot about inserts and grades! At that place we mainly used Iscar and I liked it. My new employer has a deal with Kennametal. Do you have a preference for a certain brand?
August 20th, 2009 on 5:05 pm
Ah, so you were using a Sumitomo CBN insert. Gotcha.
August 20th, 2009 on 5:05 pm
You’re right. Well we saw the insert and it looked like the diamond ones we have. It’s CBN as you said (BNX20).
August 20th, 2009 on 5:05 pm
When using CBN inserts in turning applications, it’s not necessary to use coolant. You can, but you can attain better results, in most cases, without the use of coolant. Besides, it saves the cost of coolant disposal and usage when you hard turn WITHOUT coolant.
August 20th, 2009 on 5:05 pm
You were using A CBN insert if you were turning a hardened steel item, not a diamond insert. PCD/Diamond inserts are NOT for ferrous applications, whereas CBN (Cubic Boron Nitride) is used for ferrous applications from 35 HRC and up.
August 20th, 2009 on 5:05 pm
That some hot turning! love my inserts too.
August 20th, 2009 on 5:05 pm
Hi! It’s the first time we’ve turned hardened forged steel and it was just a 100 parts. We haven’t thought of cooling it with air. If we get more of these parts we might think about getting an air line in there.
This part is an actuator of a clutch (Tractech – now Eaton) with a Brinell Hardness of 160-200. Diameter of about 190 mm.
Insert: Sumitomo Electric CNMA120408
Cutting speed/feed rate (interrupted cut): 100 m/min / 0.08
Cutting speed/feed rate (non interrupted): 110-130 m/min 0.1