Chip Breaking 1017 - 1020 Steel Tube

I am having an absolute nightmare turning 1017 - 1020 steel tube ID (approx 50 mm). Nothing will help with chip breaking. The cell includes 2 Mazak SQT 250 Lathes fed by a FANUC robot and auto gauged. The swarf is causing all sorts of issues from scoring of the bore to gauging errors and ultimately cell stoppages. Even the major tool suppliers seem to have no idea. I have investigated high pressure coolant (Sandvik Jetbreak - up to 14500psi) but the price is about US $75000. Does anyone have any ideas or knowledge of this coolant system. Pressures up to about 2000 psi have been trialled through tool and spindle and have failed. Any information will be greatly appreciated.

 

Light cuts, high rpm, and slow feed will give you a manageable bundle of "steel wool" which can be ejected by coolant fed through the spindle from the left side of the machine and out the piece-part being machined. You also could feed coolant through the tube and out the back end of the spindle and recycle it back to the coolant tank. You have picked an absolute bit*h of a material to work with, and there is really nothing that I know of that will produce a nice uniform chip. I bet the tooling distributors have suggested all kinds of high priced inserts. Good luck.

 

[WIPLASH]

What is the feed rate and depth of cut that you are trying to use now?It has been awhile since I've cut any of it.If I am not mistaken They are very gummy materials.If you are using high speed steel toolingtry surface speeds of 100,carbide 350,coated carbide 900,cermet 1300, ceramic 2500.I would definetly try going deeper cuts and faster feeds and speeds before trying a slower feed rate and less depth of cut.This should help produce a better chip to try and get the chip out of the cutting area so that the material does not have a chance to gumm up on itself or the tooling.Please be more specific with what you have been trying so that I can give you a more specific answer,such as depth of cuts,RPM, tooling being used,length of cut,and how much material are you needing to remove.Ornery Norsk is right this stuff is a bit*h to work with but it is machinable.

 

high speed steel is not an option for this material if you want any kind of surface finish. Heavy cuts may work on OD, but not ID. The minute your tool starts "singing", you lose all surface finish. I would stay with light cuts, slow feed, moderate tooltip radius (1/32), and use coated carbide at less than the mfr's recommended surface speed. Insert mfr's almost always over-state the capability of their product. Also, if your machine has a large enough spindle and the part length allows it, run the part in a collet instead of a chuck, it will make a difference in the vibration, especially in thinner walled material. I used to run 2 inch by 16 gage dom 1020/1026 and routinely held surface finish in the 16 range.