How should I harden this?

[welder19]

Hi guy's, have a hardening question figured I would get some opinions seeing as it is an area I don't have too much experience.
I have a piece of steel, no idea what grade it is but I want to harden it so I can use it as an anvil of sorts for sheetmetal work.
It is 2" thick and 4" round and basically solid, it does have a oil galley machined into it, but still basically a solid piece of steel.
What would you suggest for hardening?
Thanks,

welder19

[Mills]

Most straightforward would be heat to non magnetic quench in oil, use a new file and see if it bites and how much compared to what it does right now. Is it hard? Then heat to purple and quench again. If not hard then heat to nonmag and quench in water. test with file If hard temper, if not it ain't gonna get that way most likely.

On a large piece such as this I will always walk through the motions cold to be sure that my tongs will grip the piece securely and there is nothng in the way. I would think you will need 5 gallons of oil to quench this well.

[ThomasPowers]

Watch out for fire flare up for oil and steam on water---don't get burned and DO NOT USE A PLASTIC CONTAINER!

Note that most big steel items are not hardenable so no matter what you do it will not harden.

If the first two methods don't help you may want to try superquench on it---a search should find the receipe for you.

Remember that after a lot of long heat cycles decarburization may occur leaving you an outer surface that is soft even if the inside is harder

[Dodge]

Even if you can't harden it, if all you use it for is sheet metal, it should suffice till something better comes along. If it gets dinged, just zap with a welder and grind smooth again. No welder? May require more grinding;)

[evfreek]

Hi welder19. This piece of steel is just big enough so that I would not want to waste the carbon allotment to test it. I would hacksaw off a small piece to try. If the hacksaw won't bite, no test. It's already hard enough. If you don't want to cut off a tiny piece (it is that valuable), file test. If soft, try flame hardening (heat with oxy-acetylene small spot to critical, then splash water). Something like 4140 (possible with a shaft) will get up to about Rc 45 if you are lucky. If this works, go for it :)

[Jose Gomez]

Mix 32 oz dawn dishwashing liquid (not concentrate), 7 oz Shaklee basick OR unscented jet-dry, 5 lbs of salt, and 5 galons of water. when used to quench mild steel you can expect hardnesses in the 40 to 45 rc range. But, it's not advisable to use superquench on high carbon steel due to potential cracking. when used right you can make great short run tooling like stamps and chisels out of mild steel, a real time and material saver, and it smells GREAT! when the solution is used up it will turn from blue to green. I don't perform and post quench heat treat after I use this to harden mild steel.

[welder19]

Thanks for the advice.
The main reason I want to harden it is because the last one I had always seemed to get used for other things, not just sheetmetal, and it ended up getting pretty beat up.
I want to try and get it so that it will keep a good edge, as much as possible any way.
The last one was just a piece of 4" HRS mild steel, so the edge didn't last too long.
These I aquired from work, I have two so I guess I could do a spark test on one and get some idea of what they are.
Thanks, I think I'll mull over my options and maybe give it some sort of a try on Sat., if I succeed or fail, I'll let you know.

welder19