Novice needs help

[Karnayus]

Hi guys, so im a novice maker at best.. And ive been challenged with crafting a damascus lochabar axe, ive toyed around with the 1084 and 15n20 steel combo but it doesnt seem to have the flexibility to the blade I'd like and keeps chipping or breaking the blade even after several clean blades. Can anyone give me anymore ideas?

 

[i4Marc]

To what hardness are you tempering it?

 

[A.McPherson]

Hey Karnayus,

This is not a novice project.

However, if I were going to try it, I'd buy a suitable piece of damascus and go at it from there.

 

[Karnayus]

To what hardness are you tempering it?

Im not really sure what the hardness is, its been a "learn as i go process" so ive not had much guidance, my billets have all come out looking clean and the blades look good, they have all passed the file test so im not really sure where im going wrong on it. Ive been using my oven to temper and am thinking im getting it too hard and they are becoming brittle, but other than taking it out and using it i dont know how to test that.

 

[Bigfattyt]

Im not really sure what the hardness is, its been a "learn as i go process" so ive not had much guidance, my billets have all come out looking clean and the blades look good, they have all passed the file test so im not really sure where im going wrong on it. Ive been using my oven to temper and am thinking im getting it too hard and they are becoming brittle, but other than taking it out and using it i dont know how to test that.

The blade should be hard and skate the file after quench. Tempering should draw back the hardness. Adjust the temp up, to bring the hardness/brittleness down.

If your heat treat is poor, you can also get a blade that is hard, but with enlarged grain and more brittleness/tendency to chip/break.

Is the proposed lochaber axe for a customer or just for fun?

If I was investing that much in a significant piece of Damascus, I might consider sending it out to be heat treated by a professional with more equipment to really get the heat treat right!

 

[scott kozub]

I don't forge so I reserve my comments about that but I have a suggestion about your temper. Take your axe and test it. If its chippy throw it back in the temper but add 25 degrees. Recently I read that 25 degrees tends to be 1 Hrc. Then re sharpen / grind, beat and repeat until you have the edge stability you want. Bigfatty makes a great point that you may have over heated the steel and enlarged the grain.

This is a complicated project for a beginner. Good luck.

 

[Joshua Fisher]

It would also help if you told us more of your process, at the moment we really don’t have much info to give advice on. What are you heat treating in? I’m assuming your using a forge but I don’t know, what temp did you quench at and what quench did you use? Canola oil? Parks 50? Water? Something else? To be honest you should be quenching it into one of those three for that steel, canola works just fine but parks 50 would be more optimal. What temp did you temper at in your oven, 1084 if you have a optimal heat treat meaning right temp before quench and optimal oil, parks 50, at 400 degrees should be around 60-61rc, if it was me I would probably temper the axe closer to 450-500 and even then I may take a torch and draw back the spine to add some more toughness to the overall blade, or the alternative is to edge quench but then your pattern won’t be as nice as a fully hardened blade. Then after all of that we need to look at how thin your grinding the edge if you grind too thin even with a optimal heat treat you could have a brittle blade that chips. Think about master smiths that make swords on forged in fire that end up with major chipping during testing, I would assume they know what they are doing for heat treating but if you grind your bevels too thin, think of Japanese kitchen knives, then the steel doesn’t have as much support for chopping. So take some calipers and measure the thickness of your steel just behind your actual edge to get an idea of where you are at. The final thing is edge angle, a 10 degree edge angle even if all else is right will be prone to chipping vs say a 25 degree angle. Maybe make a test blade from just plain 1084 and play around with the heat treat, temper, behind the edge thickness and finally the edge angle then dial it in so it functions the way you want before making it from 1084/15n20 Damascus. With everything right that steel combination should work just fine you just have to adjust things to make it optimal.