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I can say that at first glance, they do look like a few anomalies I have seen a few times on my own blades after heat treat. I have nailed down the culprit in my case, tho......it is some sort of flux inside ATP-641 anti scale compound that will do this. However, it seems you indicated you did NOT use any sort of decarb. Guys.....if you are using a kiln, you should be protecting blades from decarb. NOT to be confused with scale. Scale forms on the surface, it is the carbon that has leeched out near the surface of the blade. Scale is easy to deal with, but a layer of decarb needs to be sanded off on a finished knife.
That first pic of the circle...WOW. Not sure what can cause that. I've never had any sort of strange patterning on my blades until I started using ATP, but it isn't a huge issue. I've since learned how to mitigate it...and it's not something that others are seeing anyway.
Concerning soak time with 1095, 10-15 minutes is generally recommended. Sure, 1095 doesn't have alloying, but it DOES have extra carbon that comes into solution either one of two ways.....higher heat which will not make the blade harder, it will grow grain, and you'll have retained austenite. And number two, the correct way to heat treat 1095, is with a solid soak. 10 or 15 minutes is good.
Get the kiln to temp, 1475 to be exact, and THEN place the blade in. Do NOT put blade in when kiln is cold and then ramp up. You want to heat the blade very quickly, this helps keep aus grain small. ESPECIALLY if you are not protecting from decarb...put it in when the kiln has reached temp.
The soak begins when the kiln rebounds to its target temp, after placing the blade in. Doing this does NOT cause any warping. That happens during marteniste formation after quench, usually due to imperfect grinds, or improper quenching technique.
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