Jerrod Miller

Justin Mercier posted his solution here.

You can also get 80CrV2 for just a little more per pound in thinner sections.

1050 is right on the border of useful for knives. You have less than half a second to get past the nose of the curve to get full martensite, which means generally you'll never get there, but you can get pretty close with blade geometries. Max as quenched hardness is around 60 HRC. These should make great throwing knives, or "low carbon" layers in some pattern welds. I can't really make out the fracture surface on my screen, so I can't help you out there.

I put this in your other thread, too, but read this thread.

I wouldn't recommend that at all. I or H beams are not ideal. You want a solid block, with all the mass directly below the working face. If you want to use the I-beam, you may want to put it on its edge. Check out this great thread.

Google is your friend here. It will convert units for you automatically. You can go simple with "2 in to cm" or more complicated like "2 cm * 15 cm * 1.5 mm to gallons" (just don't ask me why you would do that one). For the metals you just have to search for the alloy designation and use the word "specification" or "composition".

Looks like S355 is very similar to 1520 or 1525. That means it isn't a blade material, but could be good for tongs and such.

Also, I would assume you could find a local automotive spring manufacturer. If you can get remnants from them, leaf spring is almost certainly going to be a good blade material, and they should be able to tell you what the specific alloy is, so you'll know what to look for in how to heat treat it.

Welcome! Check out your local blacksmith's association: http://illinoisblacksmith.org/. They have an open forge every 3rd Saturday just an hour and a half from Danville. I bet someone there will be wonderfully helpful for you, if nothing else getting you in contact with the right person in your area. In the mean time, take a month or two and read EVERY pinned thread on this forum. Then read as much of the Beginner's Place sub-forum that you can power through.

Grain growth is a function of diffusion, which happens at a wide variety of temperatures, but being heavily temperature dependent, it happens faster at higher temperatures. Grain refinement happens as a result of stress followed by diffusion (grain growth). To be clear, part of grain refinement is grain growth. I know I have covered this somewhere here. This is the one I was thinking about, but I see there is an older one, too (and other smaller bits).

1550 is definitely higher than needed, as critical is probably more like 1400 (possibly even less). You should always heat to a bit above critical (like 50-75 degrees, but at LEAST 25, depending on alloy), because it takes a bit of temp loss between heat source and quench tank. It is also helpful to cross the austenitization temp at a quick rate ("hit the ground running"). Grain growth technically starts below critical, but starts getting appreciable just after critical. If you are getting up to 1550 fairly quickly (as blades in forges tend to do) then quenching right away you should be just fine. If you are soaking at all (for some reason) then 1500 is probably a better idea. Because of the alloy content in 15N20, I would think 1475 should be doable, but I'd aim for 1500. Actually, as I've said before, I'd go be eye. I like to do my normalizations by going quite a bit over, watch it cool while studying the shadows (which shows the evenness of the heating, relative to section thickness). Then do that multiple times getting cooler each time, judging by how soon the shadows form and how long it was back in the forge. Each normalization cycle calibrates heat distribution (via positioning and moving of the blade in the forge) as well as the actual temperature above critical. And of course it is grain refining every time.

That takes seconds, not 5-10 minutes (or you're doing it pretty wrong). And a "soak" is supposed to be after fully up to temp.

Also for the record, I see no reason to soak this alloy.

For the record, Ni is larger than Fe, therefore it is substitutional in the matrix, not interstitial. It is also not a ready carbide former. Meaning it is always in solution. When we talk about getting carbon into solution, we are talking about getting it broken apart from carbides and into the interstitial sites. Which in turn allows for FCC (austenite) to transform to BCT (martensite).

That probably isn't the cleanest low carbon steel in terms of chemistry (may have a bit of Cu or other tramp elements). It therefore may not weld exceptionally easily. Or it may work great. You can never tell what it is going to be like when buying A36 like that. Buying known 1020 (or similar) is safer for getting easier welds. But safer isn't always the name of the game when it comes to things like this.