O-1 flaking????

M

MCoughlin

Joined
Feb 1, 2005
Messages
471
Ok so I tried playing around with some O-1 and a torch. I got it to nonmagnetic but shortly afterwards I had some flaking occur on one side of the blade. Does this mean it had been overheated and is toast or can I still make something from this?? :confused:
...anybody....
Mike
 
Mike- I think that the flaking is scale.....dont worry about it. As long as you dont have lizard like formations in the steel you'll be fine. In my experience when the flaking occures, try to hold the temp there or a little below for a few miniuts(it can be tough), then ramp it up to a decent glow and quench. Let cool till till you can handle it and do the same thing 3 to 5 times again, then temper at 400 to 425 for 2 hrs. LEt cool overnight, then 2 more hrs.....

Trust me, you will see what I mean after you ht it several times. There is a difference....its the cycling of the steel.....others can tell you better what is going on inside than I can :p

Show some pics :)
 
was the "flaking" grey on both sides, and pretty thin? If so, this is scale, and I've got hundreds of pounds of it in my shop floor. steels oxidize instantly when they come in contact with oxygen in a heated state, it's chemically similar to rust (it is iron oxide) but it's not a big deal if that's all it is. just have to grind back through it when you finish (some people leave the steel in vinegar to get the scale off, it's pretty rough on belts)
 
Thanks for the info guys,
Pics will happen as soon as I take it out of the oven (tempering right now) and again when it's done. it's my first one to heat treat myself this way so I made it simple. Forgive the lack of artistic blah blah blah...anyway...

I kind of winged it tonight but because of all the "foolin around" I ended up bringing it to non magnetic and letting it cool three times. Then I actually ground a little scale off because I didn't know what that was until now and went non magnetic one more time. I thought that was normalizing to take the stress from grinding away...or something..however I am only heating the edge and edge quenching so I don't know if normalizing would really apply here since only part of the blade was heated. Then I went to the nice not quite blistering bright orange that I'm hoping was the right color (also non-magnetic) and quenched in canola oil at around 130 degrees (unfortunately my meat thermometer starts at 140 so I had to estimate on the dial..I'll have to get something else). I'm using a propane/oxygen torch. It has a small tip but it worked. I ran a file across the edge and it definately skates compared to the spine.

Any tips on etching (maybe something around the house could work?) I'd like to see if I got that nice temper line from edge quenching.

Also any tips on testing the blade would be appeciated. I've heard of a brass rod test but don't know exactly what it is. I'm assuming it's pressing the blades edge against it and looking for chips or dings in the blade??

Mike
 
TRy Ferric Chloride for etching.
White Vinigar I think.......a Lime works good but takes about 20 min :)
 
If you sand down to 400 or 600 apply a light buff the temper line will show. Make sure that you play the heat on both sides of the blade. Just lightly push the edge down on a brass rod and look for flex. it should not chip. make sure and wear safty glasses just incase. for O1 use manila or sisai rope atleast 1/2 inch diameter. You should get at least 30 single crunching cuts. :cool:
 
blgoode said:
try to hold the temp there or a little below for a few miniuts(it can be tough), then ramp it up to a decent glow and quench. Let cool till till you can handle it and do the same thing 3 to 5 times again, then temper at 400 to 425 for 2 hrs. LEt cool overnight, then 2 more hrs.....
Click to expand...


Are you saying that you quench your O1 blades 4-6 times? If so, why? :confused:
 
We've gotten up to 90 cuts on 1/2 sisal rope with Gary's O1 blades. use 30 as a minumum. Yours did more than that. :cool:
 
Use your cutting torch tip for HT and heat both sides evenly, take your time and don't overheat, a lot of folks HT with a torch are overheating. Warping, cracking are just about eliminated when quenched at the lower end of the quench temp range. I learned this making springs for slip joints out of 01 years ago.

Don Hanson lll sunfishforge.com
 
Danbo said:
Are you saying that you quench your O1 blades 4-6 times? If so, why? :confused:
Click to expand...
TRy it..............................you'll see. It just seems to work better.....
 
sunfishman said:
Use your cutting torch tip for HT and heat both sides evenly, take your time and don't overheat, a lot of folks HT with a torch are overheating. Warping, cracking are just about eliminated when quenched at the lower end of the quench temp range. I learned this making springs for slip joints out of 01 years ago.

Don Hanson lll sunfishforge.com
Click to expand...
How long are you soaking with a torch?
 
Brian, about 2 mins, I keep the torch on the blade 3 to 5 mins all total and sneek up on the critical temp. I will soak around 5 to 10 mins when I use my HT oven. Most of my fixed blades are large and are HT treated in my forge or oven, I only do some of the smaller ones (6'' or less) with the torch.

Don
 
I try to stay right under a tangarine color.......Does that color sound familiar to you?
 
To me it does.

So if your blade warps you've overheated?? Are there other ways to tell because warpage can happen for other reasons as well. I will try the manila rope test when the knife is finished.

I only quenched 1 time with this one but I'm tempering the second time right now like you advised. Next one I do today I will do everything as close to the same as possible except I will heat/quench... an additional 2 times.

Thanks for the help by the way.
Mike :thumbup: :D
 
blgoode said:
I try to stay right under a tangarine color.......Does that color sound familiar to you?
Click to expand...
Yes Brian, that sounds about right but the lighting in every shop is different, I turn the lights out when I heat treat by eye and I've been doing it this way for a long time with great results. I also look at the color of say a 1450 deg blade when it comes out of the oven so I have a color to judge by.

Edit to add - Heat treating is a constant learning process.
Don Hanson
 
I am also learning...no matter how many I HT.....
I think seeing the right temperature would help me also......
 
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