Multiple Heat Treats

B

Brownietown

New Member
I promise I've looked around for an answer to this question before posting. I'm new to knife making and I've successfully heat treated one blade (1084) before now. This current blade has been more problematic. Same steal, just haven't successfully passed the file test for the entire edge. I've made four attempts so far. How many times can I attempt the heat treatment on the same metal? Do I need to normalized the blade now? Have I already ruined the blade?

Thank you,
-Trevor
 
Hey Trevor. You can re-heat treat it over and over.....I don't know how many times. Just try again. No need to re-normalize or anything. You have not ruined the blade...most likely. As long as it hasn't gotten too hot, but doesn't sound like it. One thing to keep in mind, tho.....file tests are not a very good test. There are all sorts of things that can be going on that your file test won't tell you. For example......decarb. Decarb happens when carbon migrates out of the steel at the surface because of too much heat...or too long of a heat. A file will dig in where decarb is present, but there may be hard steel underneath just a hair. It's too hard for me to say exactly what's what with the info I have to go on.

But you can re-do it.....no problem. Just bring it up to 1500F, let it equalize (let it soak for a minute or two once the whole blade has come to temp), and then quench. Remember.....let it sit in the oil for 10 seconds, and then pull it out to cool to room temp. Do not file test until it's at room temp....and remember file tests are hit and miss.
 
Thank you for the response. I tried again last night with the same results. Maybe I should have my wife video me heat treat a new blade and see if anyone has advice for me. Would the best way to do that be in YouTube and just add a link in here? So frustrating after really doing my research and failing at something everyone says is dead easy.
 
Is the current 1084 from the same bar of steel the first 1084 blade was? There was some problems with 1084 being a low carbon steel rather than 1084 - got mis-marked from vendor or something like that. I don't remember the exact thread, but it was covered a few months ago here on KD. Since it's 1084, go for broke (bad pun) and quench in salt water. Even better, if you've got any of same 1084 steel, test quench a coupon of that in salt water.

Ken H>
 
You must log in or register to reply here.
Back
Top