Forging color

J

Jared Stenoien

Joined
Dec 4, 2005
Messages
1,025
After looking throught the photo's of Ashokan I noticed in the integral demo the person was forging the knife at what looked like a light yellow almost white color. Is this the color most bladesmiths forge at? I've been forging at a mid to darkish orange and am kinda wondering if this is why it's kicking my butt so much :eek:
 
It's hard to relate color to temperature especially from a photo. Timken Co did tests on forging temperatures and they go as high as 2250 F [5160 is 2150 F] . Too high and you can get overheating and burning [both grain boundry problems]. Too low and you may cause cracking and it will be ,as you have found, more difficult to forge. Each steel is a bit different . The more alloying elements the more difficult to forge.
 
Specifically, apart from being hard to forge, steel can shatter if forged at too low a temp, or crumble like cottage cheese if forged at too high a temp (will also severely decarburize and burn).
So, each steel has its proper forging temp.
Some steels can be really hard to forge, but forginving in temp range. Other wil be real bitches to forge.
This is a reason why I prefer to stay away from high alloy steels and work with old, plain carbon steel.
The easiest are the low-alloy, plain carbon, eutectoid steels from 0.50 to 0.83 % C.
Below 0.5 they won't harden properly.
Over 0.83, brittlessness can become a problem, and heat treating becomes more demanding.
 
It has been my experience that most new forgers forge at way too low a temperature. Many just get the steel a good red glow and start hammering. The steel has to be at a temperature where the metal moves easily under the hammer. If too hot it will smush or crumble, but this is much less likely to be the problem than forging too cold.Forge at 1800 to 2200F for most steels.
Stacy
 
Post deleted.

Sorry -- misread the first post, and answered the wrong question!
 
bladsmth said:
It has been my experience that most new forgers forge at way too low a temperature. Many just get the steel a good red glow and start hammering. The steel has to be at a temperature where the metal moves easily under the hammer. If too hot it will smush or crumble, but this is much less likely to be the problem than forging too cold.Forge at 1800 to 2200F for most steels.
Stacy
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Yep. Exactly. Did it myself until somebody who knew better, and was kind enough to teach me, corrected this bad habit.
:D
As the smiths of old times said: let the fire, and not the hammer, do the work for you.
After all, it's called "forging", and not "hammering" :D
 
To answer for those of us that attended Ashokan (not sure what Matt posted originally), the blade being forged during the demo was a "bright orange".
 
Many smiths, especially new guys, forge at too low a temperature for a couple of reasons. Either they got it a little too hot at one point or another and saw those pretty sparklers while their blade crumbled and they never forgot this, or another maker fed them a line about forging the uber-blade by staying sub-critical:rolleyes:. I have been doing this thing for while now and have been looking inside the steel for some time and I have accumulated enough data to draw some conclusions about how forging can affect blades. From the mill to the anvil, homogenizing the material after the pour is the best shot at improvement. Diffusive processes are driven by heat not by hammers, the break down from ingot to the small flat or round stock we work with has already entirely outdone everything we are going to do with a 2 lb hammer. Keeping the carbon out of the alloy bands and grain boundaries is very important and it will only be done with heat. Forget the hammer, use the heat.

And forget about grain size, smiths get so hung up on this one aspect that they ignore equally important issues. I have said that selling your ability to control grains size is like including “Ah can rite ma own name!” in your job qualifications. If you can’t manage to keep grain size under control you should really find a vocation you are better suited for. Get everything else right in the steel and then fix the grain size with a few quick operations.

It is actually quite simple and natural, when moving large amounts of metal get it hotter! When moving very little, keep it cooler. Forging the profile of a blade should be done at recommended forging temperatures (often around 1800F or better). This will scatter that carbon and help move things. How many books have you read that said that the greatest skill a smith can learn is to recognize proper temperatures? This is entirely true! It is all about temperature. Some heats will walk a fine line between getting the job done and crumbling steel, some heats will need to be different, and they will all change for each steel you use. That sounds a hell of a lot closer to those great skills you must learn than – just forge it all at dull red and you will have a magic blade, there’s nothing to learning that; heck we should all be forging masters if that is all it takes.
 
this discussion begs the question - what happens to the steel at forge-welding temperatures? Are we ruining damascus simply because of the process of making it?


I would imagine forging too low to be a greater problem than too high.

And that it is more critical to know temperatures visually with a coal forge, than with a gas forge.
 
Kevin R. Cashen said:
...
And forget about grain size, smiths get so hung up on this one aspect that they ignore equally important issues. I have said that selling your ability to control grains size is like including “Ah can rite ma own name!” in your job qualifications.
Click to expand...

ROTFLASTC!!!
tajo.gif


Man, this is great! Can I use this line myself? :p

If you can’t manage to keep grain size under control you should really find a vocation you are better suited for. Get everything else right in the steel and then fix the grain size with a few quick operations.

It is actually quite simple and natural, when moving large amounts of metal get it hotter! When moving very little, keep it cooler. Forging the profile of a blade should be done at recommended forging temperatures (often around 1800F or better). This will scatter that carbon and help move things. How many books have you read that said that the greatest skill a smith can learn is to recognize proper temperatures? This is entirely true! It is all about temperature. Some heats will walk a fine line between getting the job done and crumbling steel, some heats will need to be different, and they will all change for each steel you use. That sounds a hell of a lot closer to those great skills you must learn than – just forge it all at dull red and you will have a magic blade, there’s nothing to learning that; heck we should all be forging masters if that is all it takes.
Click to expand...


Well... You see, that's a reason why we ought to build a monument to Kevin.
I am myself critic and keen to experiment and get proof of so called "known truths" (:jerkit:).
I'm also lazy.
Doing all this experiments would require time, equipment, sweat. (I'm also very SHORT ON TIME... I can forge perhaps 10-15 days per year)
You do them and you are so kind to share your findings with all of us.
The community REALLY owes people like you a LOT.
 
Daniel Koster said:
this discussion begs the question - what happens to the steel at forge-welding temperatures? Are we ruining damascus simply because of the process of making it?


I would imagine forging too low to be a greater problem than too high.

And that it is more critical to know temperatures visually with a coal forge, than with a gas forge.
Click to expand...

Damascus is an interesting beast. It is so complex and the combinations are so infinite that people who oversimplify it rather piss me off. As for refining segregation, this is one operation that that can really wipe the stuff out and make the original condition quite homogeneous, that is after all how it was used for millenia. The sad irony however is that the one operation that can indeed wipe out so much of the segregation introduces a whole new segregation on a more massive scale. I have always proposed that damascus is at best a break even proposition from a funtional standpoint and with a bonus from the asthetic standpoint, but only if the smith really knows what the is doing, other wise it is a great way to make a whole lot of fittings material. Funny how the universe always balances things out isn't it;) No perpetual motion, no matter or energy created from nothing, no free lunches:(.

Yes high heat can be beneficial to the steel, but there is also extreme decarb and oxidation, there goes the universe collecting its fee again:grumpy:

The problems introduced by forging too hot (as long as it doesn't burn) are a rather easy fix with operations that are just wise to do anyhow, while heavy segregation and other issues from forging too low can require extensive thermal operations to fix which can be counter-productive when done later on.
 
Alarion said:
ROTFLASTC!!!
tajo.gif


Man, this is great! Can I use this line myself? :p




Well... You see, that's a reason why we ought to build a monument to Kevin.
I am myself critic and keen to experiment and get proof of so called "known truths" (:jerkit:).
I'm also lazy.
Doing all this experiments would require time, equipment, sweat. (I'm also very SHORT ON TIME... I can forge perhaps 10-15 days per year)
You do them and you are so kind to share your findings with all of us.
The community REALLY owes people like you a LOT.
Click to expand...

Hmmm, I think that trustworthy information can usaully be judged by the motivation behind it. I have friends and family alike reminding how I could make money off the infromation I give away for free. Perhaps I am still testing my ability to keep my scruples. When one starts selling information the desire for $$$$ almost always seems to compete with honest facts, I see the fact that I am starving while providing information as a good sign that I have no reason to feed folks a line. I really am one of the worst businessmen there ever was:(. But ego massaging can become like currency and so I shy stepping onto pedastals or having my image put there. So no monuments either, just feed back that a few of my tips managed to guide some folks out of the maze set up by so much of the popular garbage out there, that is good enough for me.
 
It was a figure of speaking, but it's true that your advice is enormously helpful, and without people like you, that share their vast experience with us poor rookies, there would be a lot less knifemakers out there and knife culture would be much more elitaristic. :thumbup:
 
Kevin R. Cashen said:
SNIP I really am one of the worst businessmen there ever was:(. But ego massaging can become like currency and so I shy stepping onto pedastals or having my image put there. So no monuments either, just feed back that a few of my tips managed to guide some folks out of the maze set up by so much of the popular garbage out there, that is good enough for me.
Click to expand...

Kevin, a little honest mythbusting that I have gotten from you backed by all of your research has probably shaved 20 years out of my learning curve! (not to mention savaing me the embarrassment of passing on bad info to the people I am teaching then having to recant it later)

Your family is absolutely right that you should publish this information and make money off of it, but in the meantime I at least am extremely grateful for the generosity of information.
If you do ever collect it into a book I will be in line for a first printing!

-Page
 
sunshadow said:
Kevin, a little honest mythbusting that I have gotten from you backed by all of your research has probably shaved 20 years out of my learning curve! (not to mention savaing me the embarrassment of passing on bad info to the people I am teaching then having to recant it later)

Your family is absolutely right that you should publish this information and make money off of it, but in the meantime I at least am extremely grateful for the generosity of information.
If you do ever collect it into a book I will be in line for a first printing!

-Page
Click to expand...

There's two of us.
I'd buy the second copy right away, and hotly recomend it to a frined who would surely buy the third.
There's a lot of "theoretical" books of metallurgy written by people who never got their hands dirty, and thought for the automotive or heavy industry.
A metallutgy book by a bladesmith for bladesmiths would be CAPITAL.
:thumbup::thumbup::thumbup:
Seriously, Kevin, give it a thought.
You help all of us on the forum, but it's only right and due that you can get some money for the know-how and the advice.
 
This is an older post, but I have my $.02 that I want to add to it.

Not sure what the event was were the smith was making the knife, but if this was a normal demonstration he/she was probably outside. The color of the steel will look different under daylight then it will under normal shop lighting. Just because it was a "bright yellow" appearance doesn't mean that it would be the same "bright yellow" under normal lighting (that would be around 2000 degres maybe a tad more). Although 2000 degrees is fine for most steel it is more towards the higher end of most basic steels for tempurature. Most basic steels (lower range 10XX series stuff) forges very easily around 1800 degrees (bright orange under normal shop lighting) and starts to have scaling issues around 2100 degrees and will start sparking it you get it over 2200 degrees (ruining the steel). This has been what I have learned about the color of the steel from my 6+ years of blacksmithing that I have been doing and I am not 100% sure how this relates to the higher carbon steel for the bladesmith, but the basic pricipal of the matter should be the same.

If you are forging inside a shop with normal lighting (slightly dim around the forge) then you should be forging at a bright orange color. If it is a dull orange color then it is probably too cool and you are wasting time and muscle strength. My teachers always told me that when the steel is at the right tempurature it is like molding clay, just too hot to touch (that is why we use the hammer anvil and tonges).
 
Kevin R. Cashen said:
Hmmm, I think that trustworthy information can usaully be judged by the motivation behind it. I have friends and family alike reminding how I could make money off the infromation I give away for free. Perhaps I am still testing my ability to keep my scruples. When one starts selling information the desire for $$$$ almost always seems to compete with honest facts, I see the fact that I am starving while providing information as a good sign that I have no reason to feed folks a line. I really am one of the worst businessmen there ever was:(. But ego massaging can become like currency and so I shy stepping onto pedastals or having my image put there. So no monuments either, just feed back that a few of my tips managed to guide some folks out of the maze set up by so much of the popular garbage out there, that is good enough for me.
Click to expand...

Kevin i could not applaud you enough for a statement such as that. true masters are not marked by the peices they make as much as the lives they touch and people they help. The lectures at Ashokan and the stuff i read here and on your site have revolutionised my way of thinking concerning blades, heat treat, forging and materials. I thank you for not becoming an info pimp, and still sharing info freely and truthfully.
 
Recent metallography work has shown me the importance of low temperature cycling before finishing the work so I would hate to see people leave this thread with the idea that I believe all forging should be done at the higher ranges. It is a common sense sort of thing, get it hot when reducung large bar stock and shaping profiles and then get progressively cooler as you get thinner and smaller cross sections.
 
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