AAAARRRRGGGG! Third "Ping" in 2 months....

happycat

happycat

Joined
Jun 21, 1999
Messages
752
This is getting frustrating. I've been quenching steel for 6 years now and forging for two. My feeling about this is that I should be getting better, NOT WORSE!!! :mad: :mad: :mad:
OK heres what I am doing. See if you can shoot some holes in my process. I pre heat the forge. I turn it off and stick the steel in to warm it up gradually. I then forge to shape. Next I heat to critical and let cool to handling temp in still air three times.
I grind to shape going from 36 to 60 to 120 leaving at least a dime to a nickle's thickness at the edge. I then normalize again three times. Then I heat my oil (olive oil) in a 12" diameter 6" deep dutch oven to 145 and bring my blade up to non magnetic, let it soak for about 10-15 seconds then pull it out and quench immediately (maybe 1-2 seconds later).
I've also had some steel just crack as I was forging it last winter...same batch. It was a nice orange color, not black. It cracked at the end I was forging, and also at the cold end in my hand. I got rid of that bar.......
Whaddya think? Am I doing something dreadfully wrong? Or should I just throw whats left in the lake and get my steel from somebody else?
Unhappy Cat
 
It isn't the steel. What type of steel ? 10-15 seconds is not what we would call a soak ,depending on the steel you need 5 minutes or more to get a good homogenious structure.
 
I would bring up my forging heats, even though its showing a little orange you could still be a little cold. Don't worry about grain growth, if your not over heating the steel and that would be up above 2300 your not hurting it, and with proper normalizing cycles you will refine the grain size back down when your finished forging. Just my opinion but to much has been stated about forging at the lower forging temps, I mean the temps where your border lining the temp to cold to forge and this can cause a lot more problems then ever forging at a higher heat. Your going to get grain growth anyway so don't worry about forging so cold, just be more cautious with your normalizing heats.

Good luck,

Bill
 
What is the quench time of olive oil?
I know the quench time of my oil, it is stated on the label and backed by ASTM.
You can heat to 1725 f. and not grow grain in 52100 and 5160 forge while light scale is coming off of the blade, straighten and fine tune as it cools. Scale size is more accurate predicting temperature of the steel than color. When it comes off in sheets you were too hot, if no scale you are probably forging too cool for major changes in shape.
Where did you get your steel? Back in the days when I was using scrap I had a lot more trouble and blade failures than when I switched to steel of known quality and all the same pour.
Hopefully within the next 2 years we will have a new book both technical for those so inclined and readable for bladesmiths who want to forge and produce high performance blades, there will also be thoughts for the stock removal crowd.

I question if the three full normalize heats after forging are necessairy, two flash normalizes followed by one full normalize have proven to be all we need.

Even forging is a critical aspect, same relative displacement of material from side to side will provide blades that are more trouble free.

Why not try a few low temp heats to around 1,000 degrees f for two hours and cool down slowly after forging and normalizing?
 
Why not just do 1 full anneal rather than 3x Normalising? Full anneal will give you better ductility and less internal stress. You could leave it in the furnace overnight to cool gradually.(Assuming you use charcoal)

Rule of thumb is 1 hour of soak per 1" of material 50-100 above the upper transformation temperature.

Then cooled at 100F per hour

Also an indepth Isothermal Transformation diagram may help if you can source one for the specific metal you are using.

As for the soak time before quenching

Q: How long should the part be left in the oven for heat treatment before removing it for quenching?

A: Rule of thumb is to leave the part in the oven one hour for every inch of thickness (Once the oven reaches the desired heating temperature) If a part measured 1/4" X 6" X 10" it would need to be left in the oven for 15 minutes before quenching.


Note: up until 2 weeks ago I wouldn't know what the blazes an Isothermal Transformation diagram was.

This 'suggestion' is based on stuff I read in

'Metallurgy Fundamentals' Daniel A. Brant, J.C Warner

ISBN: 1-56637-543-6

Very interesting stuff, not overly complex and it answers or at least gives you the means to work out a lot of stuff that you normally wouldn't know where to look for answers.

http://www.matter.org.uk/steelmatter/metallurgy/7_1_2.html

Hope this helps
 
what about the soak time of 0-1 when using an O/A torch to HT? I have been bringing the blade to a dull red and letting cool for 3 times, the bringing to non magnetic and quenching in 135 to 140 degree oil. Almost no soak time?

Can you guys shed some light on my process at the moment.... I am going to try to build a forge this summer so that may help later on.

Thanks in advance.....
 
Thanks for all the input guys. Here is some inor I left out last night which may help.
1. I did do a full aneal after my normalizing cycles. Let it sit in vermiculite for about 10 hours.
2. The steel is 5160 that I got from Admiral.
3. I'm pretty careful about forging in the orange temp range, so I don't THINK I'm forging too cold (but I'll be keeping a better eye on that just in case)....
4. Ed & Temper (Re: Soak time): I'm working with a small NC Tool gas forge. I don't have a heat treating oven which I'm guessing I would need to do hour long 1000 degree soaks. My understanding with 5160 was that letting it get up to non-magnetic then soaking if for a little bit was OK. Least ways that seemed to be working until recently...... :confused:
5> I don't know what the quenching time of Olive oil is. Maybe its time I get some "real" oil. Any suggestions on what and where?
Ed
 
Funny you should mention a ping today of all days, Happy. As I was filling my favorite coffee mug this morning, I heard a "tink" and when I picked up the mug to see what was wrong, the handle came off in my hand!
 
I might as well get my weekly bashing but I would be willing to bet that if you change quench oil you will quit getting pinged. The Olive oil is just too fast a quench no matter what you heat it to.

Try something like Crisco or go to a commercial oil.

As far as cracking while you are forging, you either started with cracked steel or you are forging cold!
 
Was it extra virgin olive oil ??? It's much better to use commercial quenching oils that's what they're designed for. Cracks during forging are almost surely due to forging temp too low. 5160 is an easy steel to forge and heat treat much easier than most.
 
I am using left over peanut oil from frying turkeys....Ummm..UM!
 
I am using left over peanut oil from frying turkeys....Ummm..UM!

I use that to spray on water pools to kill mosquito's! :eek:
 
Shane Justice sells Texaco Type A in quantities that the average bladesmith needs. His phone #307-751-0357. Address PO Box 251, Sheridan Wyo. 82801. Texaco type A is a slow quench, and works well with multiple quench as well as single quench methods.

Soak time is not as critical in thin cross sections like knife blades. The finer the grain structure you have developed through your forging methods, the lower the temperature where grain growth can occur. This is partly why multiple quench works so well.

If you want to try the same 52100 steel we use, talk to Rex Walter, 724-752-0742.

A soak just above critical for 1 hour for every lineaer inch to the center of your steel before forging promotes uniformity in the natrue of your steel.

Again, used load control shafts from John Deer tractors are the most uniform 5160 steel I have ever found. I have never seen a fault larger than one eyelash and only one of those.

Good Luck and take care
 
blgoode said:
what about the soak time of 0-1 when using an O/A torch to HT? I have been bringing the blade to a dull red and letting cool for 3 times, the bringing to non magnetic and quenching in 135 to 140 degree oil. Almost no soak time?

Can you guys shed some light on my process at the moment.... I am going to try to build a forge this summer so that may help later on.

Thanks in advance.....
Click to expand...

If I use the O/A I heat slow and even and by the time it fully equalizes it will be 5 min's or so soak time.

ED (Happycat)
I'm using Olive oil heated to 135f
I have to date on stock grind never got a ping. so I'd say it's the
stress you are forging into it or the vibration of the hammering transmitted to the colder parts could be cracking it, .

personally I think vermiculite does not work well for "some of the steels"
just because, by the time you get it in there it's past the quench noise
and/or it just don't hold the heat long enough.
a blade sandwedged between two fire bricks heated to temp (needed for the steel used )
and left to cool over night or ramping down in a controlled oven works well.
In saying, for the steels that have a tenancy to air harden.

I haven't tried it yet but ,, I'm going to grind up some soft fire brick for an insulation (from cold )
to let a blade soak in, while the oven or forge cools over night in the place of the two bricks I mentioned.

Jeff ,, your favorite coffee mug was not stress relived correctly, someone must have sliped you decaf :D
 
Thanks for the help Dan. I like the nice hammon the O/A gives to the over all look.... but I still need a darn forge....
 
jhiggins said:
Funny you should mention a ping today of all days, Happy. As I was filling my favorite coffee mug this morning, I heard a "tink" and when I picked up the mug to see what was wrong, the handle came off in my hand!
Click to expand...
You always have somethining doing that in your hand. :eek: :eek:
 
Thanks for all the input everyone. Dan, thanks for your post. I was beginning to feel like some kind of freak (well, more so than usual :D ). Its nice to know I'm not the only one using olive oil. Despite what everyone says, it seems to have been serving well these last 6 years.
I am, however, going to take the plunge and get me some real honest to goodness proffessional knife quenching oil....and forge hotter,....and do a full anneal,...and soak things longer,.....and order some new steel......

I think however, that I may have figured out what happened to my quench. Contaminated oil......The lid on the dutch oven don't fit perfectly and its been out in the rain a few times. Oil floats. I'm willing to bet that when I dump that mess out tomorrow, underneath the algae, dead bugs and frog eggs, theres water at the bottom. I'm guessing that would throw a wrench in the works. :rolleyes:
Again, thanks everyone for the imput,
I'd be lost without you guys.
Ed
 
oh man. That quench tank sounds like primal sludge :p

Let us know how the process goes....
 
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