Forged or Stock Removal Question

J

John L

Joined
Oct 28, 2004
Messages
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Say I have a piece of 1/4" flat stock of5160 and want to make a large folder out of it. Would I be better off forging to thickness of 3/16" or grinding down the 1/4" pc to 3/16"? Why? I don't mind losing the thickness if I grind it all. Just a forge or removal question.
 
If you think why grind.

I think because if you forge you would have to clean the fire scale of both sides not just one. Also you would have one flat data side to work from if you grind.

Grind one and forge another just for fun. I like to play with fire.

I am not just a fence sitter I stand on one leg with my arms out to the sides
swaying from side to side.
 
Personally, I forge my blades...But I don't do folders...It would be easier to keep everything flat and even to grind in this case. Folders are a whole different animal to make. The less hazards you put in your path the better the finished product should be in the end.....just my opinion, if all else fails...hit it with a hammer!!! LOL:D
 
If all you have to go down is a 16th, grind, if you've got to go down an 8th or more forge. Remeber, even after forging you've got to grind to clean up and you need to leave a grinding allowance.
 
I guess my original question pertains to grain structure..molecular or size of grain. Does forging change the grain from the original cold or hot rolled product? Or does only heat treat and tempering do this? So...other than ease of obtaining the final product shape..forging makes no difference? thanks
 
The grain structure is determined by the final HT process as the metal rises above Ac and converts into Austenite.The length of time,temperature,quench speed,and alloying elements determine the amount of grain.There is no improvement in grain by "breaking it up" in forging.(Sorry to offend any "edge packing" die hards).
Most folder makers use precision ground stock to assure even thickness and good surfaces.You will make a better blade that way.Any alinearity(nonparallel sides) in a folder will be a nightmare when it come to fit up time.I would say 90-95% of folder makers use stock removal on precision ground metal stock.
Stacy
 
Well, sometimes forging can improve some steels if everything is done rite.

Now, is it the moving of the steel or the multiple hot and cold contacts with the anvil and forge, and multiple thermal cylcles? I've found with 5160 and a couple others that the more hot/cold cylcles and the larger the stock is forged from the better the blade. Some steels showed little or no gain, some a big gain. I personaly think it's got more to do with the hot steel contacting the cold anvil and hammer drawing heat from it over and over as it's beeing forged than the actual movement of the steel. Will the end user notice the differance? Posibly, posibly not, main thing is the heat treat, if it ain't rite, ain't nothing rite.
 
Will, what you are saying has validity. Right now I am playing with some 1095 stock that has a nasty inconsistency running right down the center, clearly a segregation forged into a stringer during reduction. If not heated very carefully cementite will precipitate and form the coolest networks under the microscope. If the segregated cementite is present, mostly in the grain boundaries, I can do substantial work at lower temperatures and not remove the stuff. However if I start forging at recommended forging temperatures and follow up with similar normalizing treatments the little white patterns can be entirely erased. This is important since it is not a fine pattern distributed over the entire steel but a concentrated littel stringer running right down the center. Water quenched samples crack along this area every time.

Your point of forging=cycling is a good one and could allow a smith to actually improve a piece of steel that wasn’t so good from the mill, if he approaches forging as another form of heat treatment. Low temp forging that puts the emphasis on deformation alone will not do this too well since the stuff needs to diffuse, and diffusion is driven by heat. It is indeed all about the heat. Recommended forging temperatures are higher than this and allow for more complete diffusion while the deformation is occurring, and forging in pace with the heat effects will keep grains under control. And if those grains get away from you a bit, well that is what normalizing is all about. ;)

John, simple thermal treatments on a blade that thin is more than enough to refine things quite well, minus all the headaches of hammering the stock down. I personally would grind it and be attentive to the thermal treaments.
 
Might explain why even with multiple thermal cycles I've yet to get damascus to perform quite as well as a plain forged blade of the same steel. Not a big differance, but noticable when doing side by side comperisons on rope.

One thing I've noticed with both 5160 and 52100 is that repeated low temp forging at 1600 deg.F. or less and normilizing cylcles of 1600 or less produces some amazing alloy banding, looks like a very fine damasc when etched, similar to shear steel or wootz. So far I've only noticed this with 5160 and 52100, and only when forged from larger stock.
 
Will and Kevin - I agree with you that you can refine out some imperfections in bad steel by forging at a high enough temperature.
Avoiding bad steel is a better solution,that is why I recommended to John the use of precision ground stock from a good supplier.In a folder blade there would be little room for improvement by forging,as little shaping and few thermal cycles would be involved.The effects of forging that create unique patterns ,like Wills alloy banding, could actually be quite detrimental in the thin sections of a folder blade.But,regardless of whatever method the the steel is shaped by, in a folder blade the HT is going to be the major determinant of the blade's quality (beyond the steel ,of course).
 
In a reply to a recent Email to Ed Fowler, Ed informed me that his newest
52100 steel was approaching the Excalibur steel he has long been seeking.
It is in a lab now being tested and it is wootz-like.

Doug :)
Edited to add: Sorry for being OT, got caught up in the wootz post and ......
 
Will52100 said:
Might explain why even with multiple thermal cycles I've yet to get damascus to perform quite as well as a plain forged blade of the same steel. Not a big differance, but noticable when doing side by side comperisons on rope.
Click to expand...

What is the steel mix in the damascus? I find my pattern welded stuff to easily perform on par with mono-steel, and in some instances better; rope cutting being one of them. I have found heavily banded steel, many pattern welds, cable and many materials that have a higher level of inconsistency will get microscopically ragged on the edge and contribute to a sawing affect that appears very aggressive on rope, but is not quite as effective on other materials. I have found that carefully matching the steels in the damascus mix can result in more even consistence and widen its effectiveness to a more general array of mediums to be cut. With my mix I often find a higher level of hardness consistency with my pattern welded material than many of the mono-steel pieces (less than .5 HRC deviation across the surface).

In general low temperature cycling (at or below Ac1) results in segregation, while higher temperature cycling (above Ac1 to Acm) results in better homogenization. If you want a softer blade that will bend without problems and provide that ragged edge for sawing rope and paper, start with lots of carbon and cycle it low until you get banding and segregation. If you want a blade that will cut a more general range of cutting mediums, do chopping and push cuts then homogenize things well at recommended temperatures and disperse the carbides as finely and as evenly as possible. It may not bend (depending on the tempering) but you may have to stand on the cheater bar to break it.
 
The damascus I'm talking about is 1084 and 15 &20. I notice only about a 3-4% differance, but it's there. Also noticed a big drop in performance the few times I've mixed 52100 in. Under normal use you'd never notice, and some patterns like ladder and twist seem to cut better than others.

With the 52100 blades, rope cutting is not the only testing, and I've carried and used them and they out cut with the alloy banding the ones that didn't have it by a wide margine. Rope, paper, plastic, wood, cloth, meat, bone and wood, copper and steel. Even when the edge is noticably dull it still cuts where some other steels simply quit. The alloy banding is very very fine. I study the edge before and after cutting with a small, forget the power, radioshack microscope and se no signs of flaking or chiping. Not sure what's going on, but it's working.

As far as folder blades, you can also leave it just a little harder and like was said the heat treat is the most important aspect.
 
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