Bubbles in O1 Steel after HT?

RyanW

RyanW

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I did a bunch of searches and couldn't find any info on the subject. I have a 3 burner Propane Forge and I can't get the temp to stabilize below 1900F (So I am unable to do any kind of Soak at a stable 1500F Temp). I am heating the blade to Red Hot, testing with Magnet and Quenching in Canola Oil.

Question: My Heat Treated Blades are coming out with Little Bubbles (My WIP on my "First blade" had some in the photos) that are a serious pain to remove. Are these bubbles caused by Overheating the O1 Steel during HT?

BladeBubbles.jpg


Any help would be greatly appreciated!
 
What is the heat history of this blade? Has it been subjected to forging heat? Has it cooled from high heat slowly?

It looks like segregation to me.
 
BTW, O1 isn't the best steel if you don't have good time and temp controls.
 
It looks to me like it was over heated (maybe directly under a burner?) and the carbon started burning, as well as some iron.
 
If you are going only to nonmagnetic than you are not over heating, actually you need to be 80 degrees hotter yet. Seems like your forge flame is too oxidizing, can you cut back the air or up the gas to a rich flame with a reducing athmosphere? I would use antiscale compound and perhaps a muffle to shield your blade from the blast. Place a pipe in your forge of large enough diameter to fit your blade into and heat the blade up to heat inside the pipe.
 
Quit using O-1 if you can't control your heat, you will not be happy, Switch to 1084

-Page
 
Thanks for all the input Everyone,
Nathan It is precision Ground O1 Never been Heated or Cooled (By Me) Prior to my HT. I guess I better get some control of my Forge Temps. I will try using a Pipe to diffuse The Heat, I have a length of Box tube 2" x 4" that I will set in my forge to better distribute heat (Thanks Carcara I had read that previously but completely forgot about it)... I am setting the Blade directly under the burner so you may be right 65535. I may need to pick up some 1084 it sounds like.

Thanks again everyone for the input.
 
I once picked up a pyrometer from harbor freight that was pretty reasonably priced. I use it to control the heat in my propane forge. I have gotten to the point where, with some fine adjusting on the regulator, I can hold the temp with only a few degrees fluctuation. You might want to try that. 5160 is also a good steel to try, (as well as 1084) as it is hard to screw up.
 
Matt, I actually picked up a Pyrometer and a Probe that will read up to 1900F. so I guess I better just tweak the regulator and mess with the forge a bit to figure out my temps.
 
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