I have a blade out of 52100. It is profiled and ready for grinding. I have not done anything else to it. Looking for advice on heat treating. Do I need to do anything to this blade before I start my grinds? I have a gas forge that I use for all my heating.
To get the most out of 52100 it really needs a soak. Heat treating furnace is ideal. Mastersmith Ray Kirk uses it exclusively. I believe he uses a torch and differentially hardens them. Heat treating can be done in your forge, just not ideal. I would do most of my grinding before heat treat if is thicker than 1/8" . Leave around .040 on edge for meat. If you grind it too thin, it will warp. Keep your grind even and heat it slowly and evenly. Mineral oil or canola will be a good quench for 52100. I would do it at night and make sure not to overheat it. You can check with a magnet and that will get you close. Your looking for a touch above that. The steel will start to flutter and dance. Once you see that you're ready to quench. I hope that helps
I have heat treated in a gas forge for heat treating 52100 but, as stated above, it not ideal. As with all hypereuticoid steels it's easy to put too much carbon into solution and then create a problem with retain austenite. If soaked at too high of a temperature you can also run into a problem with grain growth. It's helpful if you can spot decalessence. That way you can try to keep the steel at the same brightness it had when the last of the shadow passed from the steel and try to hold it there for about 10-15 minutes. At the same time you have to keep the shadow from reappearing which would indicated recallesense and conversion of the iron structure back the the body centered cube.
As far as what you need to do before grinding I assume that you are talking about stock removal with steel from a supplier. It should come to you ready to grind so you shouldn't have to do anything to prepare it. You may even be able go get by without thermal cycling to adjust the grain size. You should, however, normalize once to relieve any stresses in the steel from production or grinding and then proceed to hardening process. If you are going to try spotting decalessance or recalessance you should do so under dim light.