soaking o1

Joined
Apr 14, 2006
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have done some searching and see most soak 5-10 mintues at 1475-1500? ok but my questions is this when u say 'SOAK" is that mean that your forge or oven is at 1500 and u put the blade in for 5 -10 mintues, or are u slowly ramping the temp over 10-15 minutes to the final soak temp and then start counting the soak time once u hit the critical number? thanks
 
The timing for the soak should be time above the critical temperature. Soaking is the process of dissolving the carbides and diffusing the carbon throughout the matrix. This only occurs above the critical temperature.
 
As mete said soak should be at the target temperature. I bring my salts up to the desired temp (1500F usually, since my O1 is almost always attached to many other layers of L6), an then introduce the steel, there will be around a 3 minute rebound time as the steel comes up to temp, I never count this in the soak. As soon as the controller reads 1500F again I start timing my soak. The time required for the steel to come up to temperature in the open air of an oven or forge would be substantially longer, and I believe many longer soak times reflect this.
 
so buy your post mete i would assume that i would need to ramp my temps up to critcial and then start counting. ok thanks kevin i think i understand now what i need to do. i shall give it a go this wekend with a few blades that i have profiled. thanks guys
 
Would you use the same 1500F soak temperature if the blade was straight O-1 or O-1 and 15N20 or O-1/1080/15N20?
 
Those combinations would not be my first choices, but hey it's your knive we are discussing so... any of those other steels can handle around the same austenitizing range as O1, so 1475-1500F should work. In fact, perhaps the high side of 1500F would help increase the hardenability of the 1080 or 15n20 to a degree that it would improve compatibility with O1.
 
Got too busy to keep up... thank you Kevin. I sort of understand the matching of metals in damascus... steel of similar hardenability and similar HT temperatures (quench and temper)... less strain, better control of end hardness of both (all) metals in mix. With a forge as a heat source, I feel like I'd have a hard time dealing with L-6 (Crucible type with it's molybdenum, especially) and Carpenter or Timken L-6 seem to be hard to come by. I mess with O-1 (single steel and damascus blades) because it is a great steel and it makes me pay attention to the upper level of heat-treating... whether I ever get there, or not.

Mike
 
I was wondering if any one had comments on my last post... thought maybe the thread had got lost in the shuffle.
 
Mike,I wanted to make sure you understood Kevin and mete.
You will bring your forge or oven to 1475-1500F and when that temperature is stable you will introduce the blade. When the temperature returns to the desired point again,start timing.What Keven was saying is that when many people say "soak for 10 min" , the first 3 to 5 minutes were probably needed to get the temp back up to critical ( the actual soak will be 5min.).The time at critical temp is the time that counts toward dissolving the carbides and making austenite.If you stuck it into the cold oven and let it heat up slowly for a long time,you would most likely pit the blade,and get a lot of decarb,since that starts at around 1275F.
As to your last post, yes it is easier to learn HT on mono steels and similar mix billets.O-1,1084,W-1 are all easy to do.1095 produces a really nice blade,but is a little trickier in that it has to get into the quench fast and has to have a fast speed quenchant.
 
Stacy,

Sorry to have not responded sooner. I do understand what Mete and Kevin were saying. Re-saying it in your words helps make the picture, thanks.

My post about L-6 wasn't worded well. I was referring to Kevin's saying he wouldn't be using 1080 and 15N20 with O-1 in a damascus billet. From other threads I learned Kevin uses Crucible L-6 with O-1. I figure using a forge for normalizing and heat-treating O-1/L-6 damascus might be easier to deal with if a person used Carpenter or Timken L-6 (no molybdenum in either) but I've got no experience so it's just "theory". I figure the O-1 being the primary metal a person ought to follow O-1 temperatures for heat-treating (and soaks), but don't know that is true either.
 
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