Dear friends
I have recently heard that it is not appropriate to cut steel with diamond wheels, because the high wear of the cutting wheel. The reason which explains this fact is that carbon from the diamond diffusses to the steel (carburizing), when sufficient heat is produced (cutting without lubrication or refrigeration). Is this assesment true? We normally cut steel with Alumina or SiC wheels when preparing specimens for metallography.
Thank you
True.
Steve
I think by "not appropriate" you mean low tool life? - kinda bizzare since tool life is relative or more to the point an economic question - low tool life is acceptable if you have no further options (diamond wire saws -also used to cut stone - have been used to cut up contaiminated nuclear vessels -Google "diamond+wire+saw")
Carburizing of iron/steel (unless under low oxygen partial pressures) is not possible since carbon oxidizes before it combines with steel - Bessemer Converter anyone? Leco (and other metallographic supplies) sell diamond wheel (copper based) as standard equipment - I never have a problem cutting steel samples (For FA) with diamond wheels with or without lubricant - it very dependent on the quality of the wheel you are using i.e. how the diamonds are held in the wheel (or wire) copper or nickel sintered or brazed (under neutral or reducing atmosphere).
You can check this out very simply by cutting nails with a Dremel Tool using their standard diamond blade ~ $13 per blade - American Science Center in St Charles, IL has small (3/4") and larger (1.5") diameter diamond wheels for alot less (check websites)
Ed Vojcak
The other thing is why would a drill sharpening company use diamond wheels. They need to cut cobalt alloys of steel. The diamonds do wear down but are burnished into the metal. I've not noticed problems with the drills. Knowing that these are not cooled (should have been) the temp is very high at the contact surface.
Martin
Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder
Ed wrote:
Cool, are they wanting the carbon to diffuse into the surface of the drill bits? :)
Could they -really- be using CBN instead of diamonds tho? :/
As far as abrasives goes, it's cost/wear vs time vs material-removed vs finish desired.
Is diamond getting cheap enough to compete with CBN when cutting ferrous alloys?
Norton on their website (and ASM books) sez: CBN is "supposed to" out perform diamonds when grinding ferrous alloys.
Alvin in AZ
Yes, CBN is better
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