Om...all i did was take this leaf spring blade up to reddish-orange heat once before takinging it out in my forge, let it slow cool by my forge then carefully heat treated it with my forge and a temperature gun quenched in parks 50. tempered at 405 F 2 times in my kitchen oven. I had struck it multiple times with a three-pound hammer just to break it at a cold shut after putting a notch in it with it locked in a vice then at my anvil I accidentally forged into it, it took two hard hits with a four-pound hammer, and my anvil to finally break it. this seems to have produced a fairly fine grain blade but I am not sure.
Hello Kevin,
The fractured end grain is not really as clean as it should be. I am not sure of all that I am seeing but you could have had a rougher fracture due to the tempering, or you could have a mixed microstructure. #50 is a bit fast for an alloy steel, but if you are only doing grain analysis it may not matter as much. You fractured surface should be a bit smoother with a velvety appearance.
Thank you. I am not sure how it might affect the structure but I was having a very hard time breaking it so I likely really stressed the grain structure of the steel as I had to smash it with a hammer about 10-20 times before I finally broke it there. that was really the shocking part to me. here's a shot of a different brake where I accidentally put a cold shut in. I am trying to forge an integrated t-shaped pummel at the handle. and was not being as careful as I should have been with drawing it down. I think it has a more velvety appearance.
the knife was also too big for my small amount of AAA...and I lost about half of it when my container got spilled recently. the knife was 12's overall. So I used 50 because that was all I had in a container that would fit the blade.
PS: i am trying to calibrate my eye to what good grain structure looks like.
Not the same steel but a shot of grain on a heat treated coupon of aeb-l. The broken sections are the same piece of steel, I cut a 15 dps edge for testing on the one side after breaking it. This was done after tempering. I cut a shallow control line with an abrasive wheel, put it in a vice and used a cheater bar to break it. I can’t imagine trying to break a knife as chunky as yours with a hammer on an anvil.
thanks.
