What am I doing wrong with my 1084 hear treat?

L

lightfootE

Joined
Mar 12, 2013
Messages
5
Ok, working on my first knife and everything was going great until I heat treated. I did the poor mans method..... Weber grill with a pile of coal, hard wood, and a hair dryer. Normalized the blade twice, getting red hot and checking with the magnet, let it air cool till it could be handled both times. Then again got the blade red hot, checked with magnet and let it sit a min longer and then quenched in canola oil, dipping in and out. After it cooled down I wanted to see if it had hardened. I cleaned off the oil and black gunk, and the steel looked almost like Damascus with all the dark splotches it had. then scratched it with a file and it was easily scratched. Still seemed really soft, unsure I went ahead and put it in the oven for tempering. Well I can tell it is still soft. I assumed that right after the heat treat it would be rock hard before tempering but it wasn't I guess. My bark river knife would easily put a scratch on the blade but I couldn't put a scratch on the bark river with the heat treated 1084. What did I do wrong? Can I try and heat treat it again or is it a one shot deal?

Thanks
 
When you say "checked it with a magnet", you mean checked for it to be non-magnetic? You should be just above non-magnetic temp before quenching.

From your description, one issue is your quench. You want to remove the blade from the heat and plunge it IMMEDIATELY in your quenching oil and agitate the blade (move it in the oil) to help it keep in contact with cooler oil. Don't stir, slide the blade through the oil so it's always in contact. The goal is to get the steel cooled as quickly as possible. Dipping in and out interrupts the cooling and will not get the steel hard.

Once it's around room temp, get it IMMEDIATELY into the tempering oven for best results. Once you're done, a file should skate across the blade.

Here's a good detailed description from Kevin Cashen: http://www.knivesby.com/knifemaking-Kevin-Cashen-treating-1084.html
 
can I go through the process again or is the it a one shot deal? Assuming I normalize and everything again. And yes checking with magnet till non-magnetic.
 
Go through it again. Think about a forged knife; it's heated, beaten until cool, heated, beaten until cool for hours before heat treat. Just give it a couple of normalizing cycles if it makes you feel better.

Good Luck!
 
Go ahead and take it a little beyond non-magnetic. A little brighter red after it becomes non-magnetic. Warm your canola oil up to about 150 F before you quench. And as noted, it should take you less than a second to get the blade into the oil and the blade needs to cool by 600 degrees in less than a second.
 
other thing to look for is decarb build up might be deep and a file might need to dig in a bit till it gets to good hard steel
also your oil.. i dont thingk you need to go in and out of it. get it in fast and "slice" the oil to get max cool oil to the blade
 
Yes, just re-do the HT.

DO NOT dip the blade in and out of the oil. Go straight from the fire into one gallon of oil and keep it submerged until cooled enough to touch ( at least 30 seconds). Move the blade up and down, or in a slicing motion in the oil. Do not move from side to side.

You want the blade about 100°F hotter than non-magnetic. That will be about one shade of red hotter. Once it is evenly at that color....quench immediately. 1084 needs no soak time.
 
You must log in or register to reply here.
Back
Top