Hardening

[Justwood&iron]

I'm wondering if you can harden a full anvil? I'm welding together an anvil, it'll end up being around 400lbs. The face will be 4" wide, 16" long, 10"+/- tall, full length will be around 24". Right now I believe the pieces are definitely a mild steel. Can dent them with a hammer, for sure on the sides not so much on the faces. So when I get completely finished, can I just put it in a fire pit, pull it out and quench it in oil?  Or should I just weld it up, then weld some 4140 on top? Or any other ideas?

[bluerooster]

I did pretty much the same thing. It came out to be 4"x8"x12" and ~109 pounds.  I left it alone, (no attempt to harden)  and have been using it with good results.  It's a medium carbon steel, mabe 1030 or so.

[Gazz]

You're thinking about putting 400 pounds of red hot steel in oil?  How big is your quench tank? Very very large I hope otherwise the oil will burn or boil away before your anvil cools enough to harden.  Also, it will not harden to any degree if you're using mild steel.  I recall reading that one anvil maker quenched the anvils in a waterfall.  The continuous flow of water got the job done.

[Justwood&iron]

bluerooster: Yeah, I had thought about that too. I'm not sure what carbon strength I have though, got the steel from a scrap yard. I guess I could try to ask someone. Is 1030 harder them A36?

[DSW HandCraft]

I don't think you need to bother with hardening, especially if it's mild steel. You can only case-harden mild steel, as far as I know, and again, I believe it's not worth the trouble. The anvil that I use is fairly soft, and it performs just fine. It can also be dented very easily if you miss-hit with your hammer. I also believe that the mild steel anvil face can eventually work-harden somewhat. Get the anvil done, start forging, and try not to miss-hit. 

[caotropheus]

Justwood&iron

Quenching 200 kg of steel is not that easy. If you quench that mass of steel in oil you may cause a fire, even worse you may burn your self and people around you.  I suggest you hard face the anvil with arc welding rods. Here is the method http://www.anvilmag.com/smith/anvilres.htm

I  built my own anvils and I hardfaced with air hardening rod locally manufactured. You can see how I did it and hopefully improve my ideas. Good luck

https://www.youtube.com/watch?v=lSpXA0b33Fg

https://www.youtube.com/watch?v=d1-gk6W5Qrs

By the way, if you do not show us pictures/video of your anvil construction, it did never happened.

[pnut]

I saw footage of an anvil being quenched under a water tower. They pretty much opened a valve on the water tower and let a continuous stream fall on the anvil.  I imagine you could use a firehouse and hydrant to the same effect. Quenching an entire anvil is no small feat, especially in oil. Let us know how it goes. 

Pnut

[ThomasPowers]

I recall reading a century old list of how high a drop was needed to harden anvils of various weights using a water tower.  You need high pressure to blast through the leidenfrost effect.  Charles McRaven, "Country Blacksmithing",  used a local VFD's high pressure firehose when re-hardening the anvil he rebuilt for instance. Just dropping it in water won't work no matter how much water is involved!

However; mild steel, A36, etc is not one to harden to anvil face hardness.  Historically anvils had a face of high carbon steel forge welded on and then heat treated to harden it.

As previously mentioned: you can arc weld on a High C face---full penetration weld!    You can hardface it---don't use spider webbing hard face alloys---Impact resistant rather than abrasion resistance!  You can just use it.  Cold steel is much harder than hot steel.  Work hardening over time will help and you can plannish dents or just regrind the face as wanted.

I do have to point out that asking how to harden is NOT a question to be thought of at the end of a project; but rather at the beginning when you are first planning what alloys to be sourced for it!   (I've heard "How do I harden my mild steel knife that I've spent days forging and grinding?" way too many times over the years...)