Ultra Fine Grain steel for Rolls 2

[Plako]

I need some help with identifying the proper steel to use for form rolls used in rolling .010 thick copper ribbon. I intend to make up these rolls by sandwiching a series of discs between two "retainers." The discs will only be .008 in thick by about 3.500 dia. with a mounting hole of 2.000 thru. The outside edge of the discs will have an included angle of 126 degrees. The critical deal is that we need to have and maintain a microfinish of Ra .10 on that outer 126 degree edge. When those discs are all stacked together, they will comprise a roll with a series of valleys about .002 deep and .008 apart from each other with absolutely no radius in the valley.

My question is: "What steel should I use that has a fine enough grain structure that can be finished to such a superfine surface?"

Would a submicro grain carbide be a possibility? I have looked at M-2, 52100, and D-2 as well as other tool steels. I guess I feel like I'm between the rock and a hard place. I need the strength for discs that are only .008 thick, but also need the grain structure for the superfinish required.

Believe me, any help will be GREATLY APPRECIATED!

 

[NickE]

I would look at the really super fine carbides. D-2 might have a fine enough carbide structure to polish that fine, I know CPM10V will.

I've finished metallurgical samples of the submicron grades from kennametal, plansee, and carbidie. With 3um polyxtal diamond the finish is really smooth, a light touch on 0.03um Al2O3 gives a bit of relief to the matrix/carbide.

I dont know how you control the edge execpt by making your discs 0.012" thick, polishing the 126deg edge, then surface grinding them down to 0.008", edge rounding is still quite possible....

nick.

Nick
I love materials science!

 

[TVP]

Look into powder metallurgy-produced tool steels like M4 or M42. Cartech (Carpenter), Crucible, Uddeholm, etc. offer these steels which have improved grindability due to extremely fine microstructure.

 

[Robertmet]

I wonder if D2 will do it but they ,Crucible,now make a CPM D2.Other CPMs like CPM154 should work.

 

[unclesyd]

Your blade form is quite common and is made by several companies. Take a look at Carolina Knife Company's list of materials and I believe they would like to make your cutter. They have made a lot of blades for me.

http://www.cknife.com/material/

 

[mighoser]

Use regular high strength alloy and deposit a DLC coating on the surface. Extremely good wear resistance, low friction, and roughness. Also, parts can be reworked at the end of their life by removing the DLC coating and reapplying.

Check out this site:

http://www.entegris.com/ProductGrou...ng_grpCoat_UltraC_Diamond_lineCoat_PECVD.aspx