User:Stever/Projects/rondeldagger: Difference between revisions

New tank fabricated it was back to the forge for the blade to be normalized and straightened (and re-normalized, and re-straightened, and re-normalized and..... you get the idea). Once the blade was stable and relieved of all internal stresses it was put through a process of grain refining which changes the structure of the metal to adjust the size of the crystal grains within it. Doing this maximizes the strength and toughness that can be achieved without lowering the final hardness too much. In the final forging process the blade was then heated to 900C, held at that temperature for a couple of minutes, and then plunged into the oil. After hardening the blade was cleaned up and the scale removed using the [[Tools/polishingwheel|buffing wheel]] before hardness testing. Testing it with the [[Tools/hardnesstester|ultrasonic hardness tester]] revealed a final surface hardness of around 53HRC which is a good hardness for this type of blade being hard enough to take a good edge but still tough enough to withstand hard use.

 

 

The parts were all laid out carefully and cleaned with acetone, and then masked off and glued with epoxy resin, this is another thing I'll do differently next time. It turned out that removing the masking tape without marring the surface finish was extremely difficult, so next time I'll try letting the resin set to a more gloopy stage before putting it all together, and cleaning off excess with acetone before it fully sets. A heavy clamp was put on the back of the tang and hammered down to make that everything was snug, then the whole assembly was put into the [[Tools/oven|process oven]] at 40C to cure for 4 hours (probably longer than necessary but I wasn't taking any chances after this much work)