Oil quenching Stainless lets hear some stories

I am going to do the method described by matt but with a oxy acetelene torch and 10w30 oil can anyone for see a problem with that? if not what Ratio should I use on the gas?
Thanks Bryce
 
Matt, not only are you very welcome but this can't hurt me either. I too hope to learn something.

Yes many of use are using forges and that is the main reason I did not argue for an equalizing cycle prior to the soak. I know it must be difficult to control sub-austenitizing cycles with a forge. So we will try to do this as forge freindly as I can, but without compriming the data sheet.

According to what I see on my sheets, I should see something in the order of 58 RHc (without deep cryo) for the single quench test piece.

The single quench test piece is in the Even Heat and the Even Heat is now ramping, as I write. It is 6:40PM EST.

I had stamped two of the three pieces Gib sent me: the single quench with the character '1' and the triple with a '3'. I also cut these two pieces to the same length so as to help keep things consistant. The remaining piece Gib sent me I am keeping in reserve in case something goes wrong. It is long enough to get two pieces from.

All is well.

RL
 
I am glad to see this testing taking place, I hope to learn from you guys! :)

Also, if you are all interested I can also rockwell the test pieces after all the work has been done so there is a cross reference. If you arent interested I understand.

I dont have any 440-C instock or I would send a piece to Paul Bos to have him do his magic on.
 
Rob, that sounds pretty good to me and I can send them to you if the other guys like. It's really not my idea for this thread. I only voluntered, as you just have. Do you trust your tester to be accurate?? I have calibrated and reference mine to test blocks. The closest block I have though is 46 RHc, which is in the ball park but I would feel more confident if I had one or two closer to 60.

Anyway, I think your suggestion is a good one and I am all for it if the principles of this thread are. I am at their disposal.

BY THE WAY ALL, the quench went text book and the piece is in primary temper now. The quench oil was at 132 F. at quench. I trust that temp. to withing a couple degrees. The temp oven reads 380 F. and I trust it within 10 degrees. The soak was 5 minutes plus as much as 15 seconds. I took a real quick look at the decarb as I was wiping the oil off before putting in temper and it looked much less than I would have expected.

RL
 
RL, sounds good to me. I do trust my tester and have checked it against other testers as well as test blocks supplied with the machine. I have a Wilson #3HM, about $4K for a new one. I have a good range of test blocks, if you like I can loan one that the lab marked 62.5 to 63.5 so you can check the high end on your tester. Flip me your snail mail adress and Ill get it out to you tomorrow if you like :)
 
Rob, you are too kind to me. I hate to put indentations in your expensive test block. I doubt I take advantage of your kindness because I know how expensive those things can be and testing on them decreases their life.

Rob, I currently have two Clark portables and one Riehle portable. All have diamond penetrators and I have been able to make them track each other from a low of RHb about 90 to a high of RHc 46. I have also made my own blocks, just for grins, at the higher C range and the three still track each other and the certified blocks. I am confident of them all but I am a firm believer in cross checking by other parties. So I stand by my agreement with you on that.

Thanks for your very kind offer but I prefer not to eat into your test block's usefulness.

RL
 
Bryce
That should work fine, I have used motor oil also and I beleive that it was 10W30. It was used, so it would have been slightly thinner but not much, and seems to be about the same weight as the hydraulic fluid I'm using now.
I can't tell you what ratio on the gas, cause I don't have a torch set up. I'm heating mine with propane from a small venturi burner (heat shrink torch) I would probably go light on the Oxygen, because you don't need the heat any more intense than it takes to evenly get the whole blade up to color. Get the flame big enough to cover the blade if you can (if your not using firebricks or something to trap the heat) heat from the spine and keep the flame moving a little bit to heat it as evenly as possible.
Have enough oil there to completely submerge the blade, a gallon coffee can works pretty good for small (4" and under) blades, since you can heat the oil in it. Have something handy to put over the top and smother it if it should happen to flash too. Motor oil shouldn't light at the temperatures your dealing with, but its better to be safe than sorry.
 
RL, no problem, and there is plenty of room for a couple hundered more dimples. Offer stands..... :)
 
Rob, does this make good sense(?): If the guys agree I send them off to you and your test results are significantly different from mine I should test mine on with your test block. How does that work??

Thanks again Rob. I appreciate you.

RL
 
10:25PM EST. The single quench test piece is in second temper.

I did a little non-destructive cheating after the piece cooled to room temp, after first temper. I took two quick tests and they averaged 59 RHc. There is no noticable scaling but of course it has decarb but not as deep as I expected to see.

I will complete all three tempers this evening but will grind decarb tomorrow and do the real Rockwell samples at that point. As said before, I will allow the three quench sample the same rest period before testing so as to make it as consistant as I can.

My intention is to take eight Rockwell tests per test piece and itemize each test result here and then give the avarage of those eight tests for each sample.

RL
 
Okay, 3:18AM Friday EST. The third and final temper of test piece 'one quench' is done and the test piece is locked by its corner tip in a vise in still air. I will grind decarb tomorrow afternoon and record the rest period it stood through before Rockwell testing so as to make sure the 'three quench' piece has the same rest period before it is tested.

Now, the dissapointing news is although I am off work tomorrow I have to be on the road Saturday until afternoon. This means there is no way I can see I can time things properly so as to start work on the three quench piece tomorrow (Friday). I do not believe I can be back in time Saturday to grind and test without being late on the rest period. So to keep things consistant I elect to start on test piece 'three quench' Saturday afternoon. Its the only way to keep this consistant. That is important. I don't like it either but that's the way it needs to be.

RL
 
This is turning out ot be a great thread. Thanks to all who contributed and to Rob and RLinger.
Just curious is there a way we could add 12hrs in the freezer to the test mix, just to see if it does anything different.
 
Just ground off the decarb on the single quench/triple temper piece. It ground very nicely and the decarb was not anywhere as deep as I would have thought. I ground it to a 120 grit finish.

I will wait til 3:20PM EST and Rockwell it. That will be 12 hours since I took it from final temper.

I'll be back.

RL
 
Well, I'd say it went text book - if I do say so myself. The two data sheets I referenced said I should expect 58 RHc if double tempered at 400 F.. I triple tempered at 375 F.. They specify austenitizing at 1900 F.. I did it at 1865 F..
------------------------------------------------
Here are the results (I rounded to the nearest 1/2 point):

58 HRc
59
58
59
59
58.5
58.5
58.5

For a average 58.5 HRc
I believe my tester to be within a half point of accurate.

One of the data sheets I referenced (the main one I referenced) is a Crucible data sheet for S90V which also has heat treat specs on it for 440C (the steel we are testing).

Here is how the test piece was heat treated:
(test piece was in oven while oven ramped to soak temp.)

Soak 5 minutes at 1865 F. (no atmosphere control)
Quench immeditely to oil temperature (132 F.)
Temper immediately at 375 F. for 2 hours
Still air cool to room temperature
Repeat temper for a total of three tempers
Rest 12 hours and Rockwell test after grinding to 120 grit.

Test pieces are 4 inches X 1 1/16 inch X 1/8 inch
Steel is 440C

Roger
 
Well I have to say I am surprised at the RC numbers with the short soak time. I wonder if it deep hardened.... The only way that could be tested is to grind an edge to the middle with a surface grinder very slowly with lots of coolant.
 
Rob, I just reviewed my HT description and noticed I had left out something of importance: I placed the steel in the cool oven so that it was in the oven while it was ramping. When the oven acheived 1865 F. the steel soaked there for 5 min., then quench.

RL
 
Try putting some brown (unbleached ) paper in with
the foil wrap with the blade. The paper will char
and absorb the O2. No O2...No decarb.
Make a small hole in the tang end of the wrap
to let expanding gas out, or the envelope
will open, and cancell your efforts.

Russ Andrews
 
Why unbleached paper? I have been wrapping the blades in clean white paper and haven't had any problems that I know of.
 
I placed the steel in the cool oven so that it was in the oven while it was ramping. When the oven acheived 1865 F. the steel soaked there for 5 min., then quench.
Click to expand...

That explains a lot. I had thought the test was to simulate a 5 minute soak time like using a forge, putting the steel into a hot furnace and soaking for 5 minutes once it was equalized.

White paper, brown paper, wood chip etc has all worked for me, but anymore I dont use anything.
 
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