Hi guys,
Long story warning!
I recently tried my hand at some pattern welding using (the equivalents) of 1084 and 15N20 I bought from Achim Wirtz. I forged a billet, hot cut off two pieces to make into keychains for presents. I then forged a blade out of the remainder of the billet, or at least tried to. My mind wondered a bit too long when the tang was in the forge and it ended up in two pieces. So decided for shits-'n-giggles to harden the piece that used to be the butt of the tang. I heated it up to a bit above non-magnetic and hardened it in water (taking cover from the steel snobs at this point). It hardened alright, snapped clean in two with a slight rap with a hammer whilst clamped in a vice. I then ground it with a 60 grit belt and etched it in battery-acid which I had just bought (used vinegar before, wanted to try something else). Within something like 20 minutes I had a fantastic contrast, pretty deep etch with the 1084 being quite rough. I though: Hey, this battery acid sure beats the hell out of the old vinegar.
Next I finished the keychains to 600, hardened them (using an oxy-acetylene torch iso the coal-forge), tempered them for an hour and a half at 250C (turned blue), buffed them and etched them. After a couple of hours only slight etching depth and maybe 20% of the contrast of the other piece (the 15N20 also being darker than in the other piece, makes sense when you look at the etching time).
Observation: The overheated piece was quite grainy on the breaking surface.
Observation: The overheated piece etched very fast and quite coarsely.
Conclusion: Grain growth has a significant impact on etchability.
Question: Is my conclusion correct in YOUR experience? One of my suppliers from my dayjob, who etches steel for a living (chemical machining) confirmed the relationship between grain size and etching behavior., but I'm very interested in your thoughts.
Question: How to get the awesome contrast from the abused piece in "properly" treated material? Even more aggressive acids?
Thanks for your time!
Cheers Rody
Long story warning!
I recently tried my hand at some pattern welding using (the equivalents) of 1084 and 15N20 I bought from Achim Wirtz. I forged a billet, hot cut off two pieces to make into keychains for presents. I then forged a blade out of the remainder of the billet, or at least tried to. My mind wondered a bit too long when the tang was in the forge and it ended up in two pieces. So decided for shits-'n-giggles to harden the piece that used to be the butt of the tang. I heated it up to a bit above non-magnetic and hardened it in water (taking cover from the steel snobs at this point). It hardened alright, snapped clean in two with a slight rap with a hammer whilst clamped in a vice. I then ground it with a 60 grit belt and etched it in battery-acid which I had just bought (used vinegar before, wanted to try something else). Within something like 20 minutes I had a fantastic contrast, pretty deep etch with the 1084 being quite rough. I though: Hey, this battery acid sure beats the hell out of the old vinegar.
Next I finished the keychains to 600, hardened them (using an oxy-acetylene torch iso the coal-forge), tempered them for an hour and a half at 250C (turned blue), buffed them and etched them. After a couple of hours only slight etching depth and maybe 20% of the contrast of the other piece (the 15N20 also being darker than in the other piece, makes sense when you look at the etching time).
Observation: The overheated piece was quite grainy on the breaking surface.
Observation: The overheated piece etched very fast and quite coarsely.
Conclusion: Grain growth has a significant impact on etchability.
Question: Is my conclusion correct in YOUR experience? One of my suppliers from my dayjob, who etches steel for a living (chemical machining) confirmed the relationship between grain size and etching behavior., but I'm very interested in your thoughts.
Question: How to get the awesome contrast from the abused piece in "properly" treated material? Even more aggressive acids?
Thanks for your time!
Cheers Rody