I have found it. I didn't crack it, it was already cracked. I just made it bigger. There was a splinter of metal that had years wrothof rust built up inside.
I got the ends of the cracks welded up. I didn't know I could run 140 amps through a 1/16 inch tungsten. Next step is hook up the water cooled torch, put in a 1/8 tungsten and collet in there and hit it with 250 amps.
I preheated and welded the crack with 309 filler and the anvil is very hard. I bought some of those knife hardness testers, from Japan to get an idea how hard it is. It's harder than I thought it was going to be. A tig welder running about 320 amps cuts into high carbon steel like a light saber.
Well it's definitely hard. I tested it with my hardness files. The 60rc file scratches it but not very well and the 55rc file slides.
I just picked up about a 2' section of track for 25 bucks at a metal scrap yard . Been wanting a small anvil just for the rare times I need one . I didn't think about any heat/tempering for it . And ,, I didn't even think of having it milled to be flat on top. I was thinking of picking up another piece to flip upside down for a flat surface. Thanks for the thoughts.
I'm building my anvil for the end of civilization. Might as well mill and heat treat it now while I can and fix it or replace it if I F it up.
Well I finally finished the anvil in the original post. I hope. I tried to mill it, it was too hard, then I annealed it and it was nice and soft. Tonight it went back in the coal furnace and went in a used motor oil quench. I did all the maths and figured that a 55lb anvil heated to 1,500f going into 8 gallons of oil with a 2 gallon water jacket will control the temperature of the oil a least somewhat. And it did. I only got a mild fire. I was expecting a 12 foot fire ball. The 2 gallon water jacket ended up being more like 3 and a half. The oil temperature went up and the boiling water jacket stole heat from the oil so the flare up wasn't even worth taking pictures of. One quick squirt of CO2 put out the flames on the first try. I dried the oil by heating it to 280f so it would drive off all the water. It tried to boil over twice when I was drying it so that could have been bad had I just dunked a orange hot anvil into a trough of wet oil. The oil was quiet cool by the time the anvil was ready to go in. After the anvil was quenched but still smoking hot I buried it in hot ashes and it can slowly cool all night. I didn't hear this one crack. If it's not hard enough I'll do it again in water.
The hardness is only about 45rc. Back in the fire it goes. I guess oil just can't cool that much steel fast enough to make it hard. The annealed hardness was less than 40rc as the 40rc file dug right into it. After the oil quench the 40rc file slid but the 45 eagerly dug in.
