Hello Jerry. I usually shoot for a 59-60 rockwell on the cutting edge. One question, what quench oil did you use? As quenched 5160 should be around 64 and W2 should be around 66. I temper my 5160 at 400 for two hours and then at 400 for another two hours, so the two times two. W2 gets 450 for the two times two. The soak time was good as was the quench temp of 1525. Makes me think maybe the oil was too slow or your tempering oven temp may be off. Curious, let me know.

Brion

Hi Brion, I used parks 50, heated it up to 100 degrees. If I was taking my oil temp reading at the top, could it be my oil is to hot? I have a new Evenheat kf18stp. I would have to take my pyrometer out of my forge and verify the temperature is correct in my oven. I know when I was trying to temper the 5160 in the oven the temp spiked to 500. Thank you, Jerry

Brion I used an over thermometer to check my tempering oven to keep it at 400 and 425 for W2. Maybe my quench oil to hot or my heat treat oven temp not correct. As I said the oven is new, first time using it. Jerry

The spike to 500 in tempering would definitely have an effect and would give you a rockwell of around 51 to 54 with 5160. The parks is fine and its working range is best between 80 to 100 degrees, so no issue there. A little fast for 5160 though, but it will harden it just fine. I would look at temperature in the new oven as a possibility. It may take a few runs or cycles to even it out. Checking with the forge pid would be good.

Brion

Good morning Brion, What quench oil would be better for 5160? I have Brownwells tough quench. I'll cut some test pieces and do some more testing. Jerry

Hello Jerry

Something I might add. Set your temp on the Evenheat oven ahead of time, so the oven is thoroughly

heated to set point. Other wise It will give you false inside temperartures. The oven should'nt very four or maybe five degrees.

Russell

Hi Russell, I have been putting the knife in at start up and at 500-600 putting anti-scale on then continue to target temp. Jerry

Hi again Jerry

If you are using your Evenheat oven for both heat treating and tempering, your oven will need to be cooled below your tempering set point or it could spike above once close up.

I use my oven for one or the other. I don't use it for both heat treating, and tempering.

The Evenheat oven works great, if you give it good amount of time to reach temp set point

Russell

Jerry the tough quench should work fine for 5160. It will need to be heated to 120 to 140. One thought, are you doing your rockwell testing on ground steel or as it comes out of the quench with no grinding? Could be de carburization on the blade which will read low.

Brion

Jerry,

As has been said it is typically better to place the blade in a preheated oven both for H/T & temper. For H/t this will lessen the chance for grain growth and for the temper will lessen the chance for overheating the blade. I also use an Evenheat and will apply the anti-scale while the oven is coming up to temperature. It will usually be dry enough by the time the oven is at temperature. Also, after you place the blade in the oven be sure to stop & restart the program so the controls realize that the inside temp has been reduced.

If you are using the Evenheat for tempering it will require letting it cool which will take some time as you don't want for it to cool with the door open as that will effect the lifetime of your elements. It's also a good idea when tempering in the Evenheat to set the ramp speed to level 1 or 2. It won't stay on temp as well with a high ramp speed.

Are you normalizing the blades? It's possible that if you have large grain size that you could be getting uneven hardness levels throughout the steel and false readings. As Brion said, if you are H/T'ing without doing much grinding then de-carb could be giving you false reading as well.

Gary

Yes, I ground the scale off first to get a good reading, I did not know this but had done it, just made good sense. I was also cooling the oven down for tempering leaving door open a little, I will not do it again, thank you. I did normalize for three cycles, but not sure of my normalizing temps we exact, may have been all about the same temps. Need to control them more closely. I am doing my tempering in kitchen oven now with an oven thermometer to get more exact temp and time and am watching the thermometer reading for preheat instead of the over temp, because not even close on preheat and about 10 degrees +/- depending on the temp.

Jerry

Ok, Can I put the knife in again and harden it? What are the proper steps I need to go through now? Jerry

I may not be the best guy to give advice, but since no one has answered yet...here's my $.02 <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//wink.gi f' class='bbc_emoticon' alt=';)' />

You can go through the hardening process again, but success or failure can ride on a few different things. If it is still the same thickness (you didn't start grinding on it post tempering), success is way more likely IMO. Some might suggest you anneal the blade, then do the 3 thermal cycles, ending in quenching and into the tempering oven. If it already is too soft for what you want, I'd think doing a proper set of thermal cycling without the annealing step would be fine.

Thankfully, the smart folks will be along to help both of us figure out the "right" way <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//biggrin.gi f' class='bbc_emoticon' alt=':D' /> . And by the way, glad to see a fellow Idahoan here.

Jeremy

Jerry, I would just give the blade one normalization, heat to 1550 and air cool to black, then heat treat again. 5160 is pretty forgiving that way.

Brion