Need advice on heat treating 80CRV2

Oh wow, I have never seen a rack like the one Luong just posted. Well, if it's something like that, which I never would have imagined anyone using, then yeah, that's a possibility.
 
Taz said:
Was the rack fully heated when the blades went into it? I would think if is was heated fully to the same temp as the kiln before blades were put in, it wouldn't have much effect? Or are the blades cooling the rack down when they go in, slowing the heating process?
Click to expand...
I preheat the rack with the kiln and it goes up to temperature along with the oven. I also let it preheat for at least 20 minutes. If the blades are cooling it down, I don't know. I hadn't considered that.
 
Cypress Creek Knives said:
I'm likely a bit out of the way. I'm in central IL. I am trying to move it asap as I need to free up some space in the shop, and it sounds like a couple other guys are interested in it as well. I'd recommend checking facebook marketplace. You can find a nice old Wilson for not too much money
Click to expand...
For sure. I appreciate your offer! I was looking at marketplace and there are quite a few available. Are there any particulars that I need to watch for when purchasing? Or anything that I need to avoid?
 
Taz said:
Yeah, I picked up a Wilson 1JR for $325 last winter on Fb marketplace! $23 cheap indenter, some tuning and it's dead on. Got a few anvils and test blocks with it, too! Look for ones that have the entire weight stack, or make your own "stack" and hanger. Indenters are easy to pick up, too. Amazon and Ebay have them all over.

I have scans of several older manuals that talk about the calibration/adjustments to make, too!
Click to expand...
I appreciate this. I wasn't sure what to look for or what to avoid when shopping for used ones on marketplace. So, I'll keep that in mind. Thanks!
 
Keanen said:
That's the rack I use. Do you think a longer soak time will help? I have been preheating the rack in the oven beforehand.
Click to expand...
20+minutes soak would ensure blade in the middle aust properly. There are 3 main factors need mitigation to resolve heating issue: radiant occultation, flow(gradient air) restriction, rack divider mass.
or easier just use standard ht rack.
 
Keanen said:
For sure. I appreciate your offer! I was looking at marketplace and there are quite a few available. Are there any particulars that I need to watch for when purchasing? Or anything that I need to avoid?
Click to expand...
Make sure it reads in rockwell C. Before you buy one, feel free to send me a message with the link to the sale and I can confirm if it is the right thing
 
Question about the oil temp. If using AAA quench oil you would warm to 120 degrees still yes?

So it’s about the oil viscosity more than the temperature of the oil?
 
AAA is listed as 130-160 for operating temperature range. Parks 50 is 50-120 temp range. Outside of those temps, you may get different results than expected. I tried some Blue #2 in Parks 50 and it didn't harden. I had done a couple small hunters before; these were some 3/32" 8" chef knives, so a bit more steel mass. I did all 4, all were in the 40-low 50's. I went back out to my quench tank and it was around 150! A couple days later, I redid the HT, with the colder oil and I found that the oil can get hot quickly, so after a couple blades, I had to wait to let it cool back down again. I check my oil temps now before I start and after each blade to make sure I am still in the correct range. I try to use Parks 50 since I don't need to pre heat it, but I have 2 containers of it now so I can alternate blades and not get the oil too hot that it won't work.

I would warm up AAA. Warmer oil is thinner and transmits heat better, but if you get too warm, it may not quench fast enough. I haven't played with the AAA enough to see what the lower temp threshold is? IIRC, I did some 52100 in it at around 90 degrees a few years ago and I believe it fully hardened? It was the winter and I put a couple chunks of steel into the oven/kiln to heat up the oil, but due to it being so cold, it only got up to around 90 or so.
 
Thank you for the info. I always warm my AAA oil and when I read the info about not warming parks 50 I got a little confused but now I understand!!
 
blgoode said:
Thank you for the info. I always warm my AAA oil and when I read the info about not warming parks 50 I got a little confused but now I understand!!
Click to expand...
I asked this question a while back and the consensus was not about thinness or initial quench speed but rather the control of the the cooling at the low end as the steel starts the martensite transformation. So warming up the oil will slow that critical point when cracks can happen. Think like how water quenching is good initially but after reaching the martensite transition spot you can get the dreaded "ping" of cracking. So using the oil cold should work fine with many steels but could be too fast for some like o1. At least that is what the few responses to my thread made it sound like.
 
I’ve always just used aaa oil heated to 125 so that’s my only experience.
 
blgoode said:
I’ve always just used aaa oil heated to 125 so that’s my only experience.
Click to expand...
Using the oils at their recommended temps is the best way for ht consistency of course. I have 5 gallons of each p50 and aaa and last year I heat treated about ten items from a couple blades to some punches for blacksmithing and the last 2 didn't harden cause the oil got too hot and that was aaa warmed to about 130f starting out. So even with 5 gallons the oils can change a lot and cause inconsistent results. I am in process of designing quench tanks that will have cooling coils and a heating element for the aaa so I can control them better. It used to be that ht wasn't as big of a deal with thicker edges and more obtuse angles but when one starts chasing actual cutting performance with thin edges and acute edges the ht starts to show up with edge rolling or chipping at high hardnesses.
 
Taz - what is the volume of #50 in your quench tank?

My 28X6" tank holds 3 gallons of #50. My results for quenching large kitchen knife blades in #50 is it rises about 10° per blade quenched. After about 5 blades it needs to cool down. If I am doing more than 5 blades, I have a metal water bottle full of oil in the freezer. I dunk the bottle in the tank and pull it up and down. It drops the tank back to around 80° in 5 minutes.

TIP - wipe the bottle off with paper towels and put in a large zip-lock bag. Then place in the freezer. That keeps oil and smells out of the freezer.
 
It's a 4 x 4 x 24 with about 19" of oil? IIRC it's about 2 gallons ish?

Interesting idea about the metal water bottle! I may have to try that!
 
You must log in or register to reply here.
Back
Top