Spheroidal Anneal

gnique

gnique

Joined
Apr 25, 2007
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I just started work on a new blade and used some O1 that is precision flat ground from a very good source. That stuff is harder than a dollar's worth of jaw breakers. So I go back to a post by Kevin wherein he talks about how to spheroidal anneal. TEN HOURS!!!??? Is that right? Go to 1375 deg, hold 45 minutes and drop to 900 deg at 50 deg / hour to 900 deg. That, by my engineering analysis, works out to 10 hours and 45 minutes. Someone needs to tell Kevin that is NOT a good or economical routine. It DID eat a carbide drill bit and a LOT of cutting blades, however. But is that RIGHT? 10 h 45 min? I am thinking about taking up quilting. Doesn't mete or Kevin or someone have a better routine that takes less time? How about using a magnet - I have a real big magnet. I think that I will try soaking it on that magnet overnight and see if that helps. Nicholas
 
for o-1 to aneal it you just need to cool it slowly. 10hrs seemes excessive if you have a ht kiln I would recomend brining it up to 1400 F, or whatever the right annealing temp for O-1 is (cant remember it off the top of my head) soak for an hour, and let it cool in the kiln, that should be slow enough, but I am not speaking from experience.
 
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gnique said:
I just started work on a new blade and used some O1 that is precision flat ground from a very good source. That stuff is harder than a dollar's worth of jaw breakers. So I go back to a post by Kevin wherein he talks about how to spheroidal anneal. TEN HOURS!!!??? Is that right? Go to 1375 deg, hold 45 minutes and drop to 900 deg at 50 deg / hour to 900 deg. That, by my engineering analysis, works out to 10 hours and 45 minutes. Someone needs to tell Kevin that is NOT a good or economical routine. It DID eat a carbide drill bit and a LOT of cutting blades, however. But is that RIGHT? 10 h 45 min? I am thinking about taking up quilting. Doesn't mete or Kevin or someone have a better routine that takes less time? How about using a magnet - I have a real big magnet. I think that I will try soaking it on that magnet overnight and see if that helps. Nicholas
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Oh yeah it really does take that long, I use O-1 and my full anneal cycle is 16 hours from room temp to room temp.
If you want more economical then use 1084.
Del
 
You could do a subcritical anneal. 1500 for 30min, quench, 1320 for 30 min, air cool.
 
It depends on what you need to do after anneal. The subcritical anneal does a good job but a full anneal is better. Try subcritical first, if that doesn't work go full.
 
Did you use cutting fluid when you were drilling? I went from ruining a bit in two holes to never needing to buy the same size bit unless it snapped by using a good cutting fluid.

What do you mean "soaking it on a magnet"?
 
gnique said:
... Someone needs to tell Kevin that is NOT a good or economical routine...
Click to expand...



:rolleyes:Boy this place just gets warmer and fuzzier all the time:). O.K. you have my attention, please fulfill your need.

But of greater need is setting the folks straight at ASM that publish the Heat Treater’s Guide and countless other resources on these steels, and let’s not forget any of the spec sheets from the manufacturers and suppliers of O-1. I think those folks really need to know why what they have developed as an optimum anneal is “NOT” a good routine when compared to your alternative. Which brings me to a rather vital point- what exactly is your alternative?

Of course one could heat it up to nonmagnetic and stuff it into wood ash, vermiculite, a cooling forge, etc… and deal with the segregation, proeutectoid carbide, and just buy lots of cheap tooling. Delbert is spot on here, if one can’t handle the more involved heat treatments of a more alloyed steel then save the money and stress and stick with 1084. But if my method (which it is not, as I am just the messenger of information you may not like) is not good or economical, then your method is…?

There are two ways to achieve a spheroidal structure, you can go slightly above Ac1 and utilize the divorced eutectoid reaction, or stay below Ac1 and take your tempering carbides into larger spheroids. For the first you actually only need to cool to below 1000F at a rate of 40F/hour, but the easiest thing for me to do is to soak the steel, then press the button to start my ramp function program, which shoots for 850F, and go in the house for the evening. The next morning I begin work on dead soft steel that never squeaks my drills, breaks my mills or tears the teeth off my saws, which is infinitely more economical than skimping on the bit of electricity used to insure this. I have received much feedback about how my damascus is easier to cut than others by those who bought bar stock for machining. Now if heavy machining outside of the grinder will not be needed, then a quench and some cycles to 1275F – 1300F should get you some fine spheroidal structures as well, but it will still be a crap shoot for your mills and drills. I have cited industrial references here, however this method has also been completely confirmed by my decades of working with O1. But hey I am open to suggestions, so I am all ears as to any better methods you have developed, the magnet is an interestingly different approach, what should this do?
 
D-E-T there s that word.............
yes it really does take that long. If you go to posts that KC has written in the start of this forum you can read all the goood things as to why it takes this long. Start with those posts it will help.
 
There is an old saying in Tennessee where I grew up: Never get involved with any project that starts out with "Well, the FIRST thang Immo do is get a real big magnet..."or: "Ya'll come over here and watch what happens when I shoot a hole in this thang.." or: "Lets just see what happens when you poke a stick in that hole". Believe me, those are not the only sure signs of impending loss of blood but they DO tend to point the way. I rolled down a 200' hill one time in a barrel. I also drove a 1951 Henry J off of a 10' vertical river bank - sober and on purpose. One time I jumped into a swimming pool from a third story porch. I have jumped out of airplanes 1375 times and 11 time out of a balloon. I have been in three air crashes and spent a year as an FO in Viet Nam. I think I will forget the magnet and program my Even Heat oven. Thank you for your help and your considered opinions. Nicholas Jasper
 
I did run the spheroidal anneal routine that Kevin recommended. In fact, I set the oven and let it run over night. It worked!! I tried a file on it before I went to work this morning and I could feel the difference. I thought about trying to whittle on it with my ZT 300 pocket knife but thought that might be a bit much. Nicholas Jasper
 
Kevin, do you have photos of full anneal [as you described ] and subcritical anneal of the same material ? That might make it very clear.
 
I suggest the bloke should just go and read the ASM's book on heat treating, which includes lots of nice pictures. Who cares how long good heat treatment takes. Beyond annealing, there's even more time with normalising, quenching, deep cryo, tempering. Why worry about time for high performance blades? If you want to produce cheap blades you will find it hard to compete with large companies doing large production runs using sheet steel and stamping dies to do the blanking.

Personally I consider there to be better materials than 01 as well but thats just me.
 
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