15n20 HTing

Bring to 1480, hold a couple minutes and quench in oil. Temper between 325-425 or so, I use about 350 for roughly 60 RC.

I use 11 second oil, I think most oils will work well. 15n20 is usually so thin it cools fast.

It is a relatively easy steel to heat treat.
 
Daniel probably does a lot more 15N20 than I do, so go with his parameters.

I austenitize at 1500F for 10 minutes and quench in medium oil. I pull from the oil after 10 seconds and place in quench plates. When cooled to room temp, I immediately temper at 375F.

RC is 59-60.
 
bladsmth said:
Daniel probably does a lot more 15N20 than I do, so go with his parameters.

I austenitize at 1500F for 10 minutes and quench in medium oil. I pull from the oil after 10 seconds and place in quench plates. When cooled to room temp, I immediately temper at 375F.

RC is 59-60.
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That sounds great too. At 1480 I have to be careful making sure everything is fully soaked and up to temp. I probably soak a bit longer than that in actuality because I'm conservative when I start my timer.

I also do a 7-10 second or so quench then into the plates. I wait until just after the steel stops smoking then into the plates fast.

350 to start on temper for me but many go to 385... I am really impressed by 15n20, it seems you can't go too wrong with it.
 
Is it possible to do it without plates? Could I just let the blade cool in the oil?

So I would do the following:

Heat to non-magnetic and let soak for an extra 30 seconds to a minute. Then quench in oil heated to 120-130. Temper for twice for two hours each around 375.

Does that sound about right for both 1084 and 15n20? Or is there a better way?

Could someone post a recipe for a beginner that I can fully understand? I'm pretty sure I get it, but I just want to make sure. :)
 
That won't work well with 15N20.

15N20 needs a long soak time to allow the alloy ingredients to get right. It also needs better temperature control than non-magnetic and a guess at what it really is.

Plates help with 15N20, as most are thinner blades and warp is better controlled with plates.

1080/1084 may have similar temps, but that is where the similarity ends. It is a very different steel.

If you don't have a temperature controlled oven that allows 10 minute soaks, 15N20 isn't the steel for you, unless you send it out for HT by someone who does have the right equipment.
 
A Master Smith by the name of Ray Kirk works extensively with 15N20 and makes a ton of fillet knives.
He will austenize at whatever temp for however long with blades that are just profiled - he grinds post-hardening.
Anyway, with full thickness blades, he plate quenches only - no oil quench.
Get pretty incredible performance.
 
If I were doing a stock removal knife out of 1084, would I have to normalize before HT? Or is that just for forging?
 
Erdbeereis said:
If I were doing a stock removal knife out of 1084, would I have to normalize before HT? Or is that just for forging?
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At the moment, I only make knives via stock removal. I still normalize every blade. Probably overkill with bar stock. But I figure with what little time it actually takes, it can't hurt and can only help. I know a lot of other stock removal knife makers who don't and they get fine results as well.
 
I normalize because I feel it helps remove stresses from when the stock is sheared and hammering and grinding... I usually tell non-knife makers its a stress relieving cycle.
 
Thanks, how do you normalize? And do you let the blade get completely cool in the quenching oil, or do you take it out before?
 
In thin section, 15N20 can be HTed an air hardening steel. It can be quenched in an air blast or with quench plates. This minimizes warp with only a loss of a point or two as-quenched hardness. With the proper temper, the final hardness is the same. If you are grinding thin blades in 15N20 after hardening, this would be the optimal method.
 
Gotta ask this. Most of your recipes appear to leave the 15N20 a fair bit softer than 1080 or 1084 treated the same way. Why is that? 1084 austenized at 1500 and quench in say Parks 50 should have an as quenched hardness of around 65 and if tempered at 375, should be around 62 as 350 will give you 63-64 and a 400F temper, which seems to be a popular one and one that i use for "hard use" knives, should give you 60-61. is the nickel dropping the as quenched hardness? it doesn't seem to do much of that when you compare L6 to O1.
 
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