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So recently I was involved in a debate about steel, more precisely, modern carbon steels used in knife making.  This may seem like a bladesmithing topic but I think it applies better to general forging of modern carbon steel.  at any rate its a good study of material science. 

It started as I overheard some general conversation about forging a complicated knife shape vs stock removal to achieve the same shape.  the argument was that in a "modern carbon steel" it dosnt matter whether you forge the shape or mill or grind it away, it would achieve the same strength once it was properly heat treated.  this went against my general understanding of forging of parts, blades, or whatever.

my addition to the conversation was that, all things being equal, a forged shape would be stronger.  if two parts were made, one in a machine shop via stock removal, and one in a blacksmith shop via forging with minor finishing as required to achieve similar tolerances.  then both parts sent through the same heat treating process, the forged one inherently retains a more cohesive grain strength, making it stronger.  the reason for machining is keeping tighter tolerances and speed of manufacturing.

the argument back was that, when properly heat treated, original grain patterns do not affect finished strength, they are mostly reset.  and that the talk of grain strength was just a carryover in blacksmithing from the wrought iron days of very large grains where it mattered greatly how the grain was oriented.

now I don't discount that the difference may be minor, but I find it impossible to believe a forged shape isn't stronger.

 

 

 

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This is a common misconception on the scale of blade making. If you're talking about making crank shafts forgings are stronger, not a lot but some. The real reason crank shafts are forged is it's about 50x faster and a less wasteful of steel. 

Do you know how that 5/16" x 2"  piece of O1 got to be that size? It was forged from a billet of tool steel weighing oh I don't know 100 tons? About a 4' x 4' x 12' steel ingot gets pinched off the continuous caster in the mill. It drops onto a table that manipulates it into the first set of rolls and it passes through roll forge after roll forge till it's a length of the above dimension steel + a margin to grind to exact dimension but by then it's been cut a hundred times or it'd be a miles long ribbon going a couple hundred miles an hour.

Go ahead grind it to shape and heat treat it. Nothing a mere human being can do to it with hammer and anvil or power hammer can make a significant difference. Frankly considering the difference in grain (crystallography) elongation between mill finished and as forged by a bladesmith, you actually have much better grain structure from the mill.

Proper heat treat helps reduce the grain growth (adverse crystal boundary junctions) CAUSED by the bladesmith.

Go ahead link us too all the articles written by bladesmiths saying otherwise. I love the guys but it's mostly puffery just like the Ford Chevy debate or one team over another.

Frosty The Lucky.

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9 hours ago, C-1ToolSteel said:

Look up a video of how steel stock is manufactured. You should have a different opinion by the end.

Yes seen them, and been in mills first hand.  unless im missing something, it only strengthens my thoughts on trying to retain the grain from the steel mill.  

Eh anyway im not a bladesmith, just curious.

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Now, there ARE some people who believe in something called packing. I'm not sure if it actually improves edge retention or not, but some people say it does. Sounds similar to cold rolling.

But as for regular forging, like Frosty said, when it has been worked from a 100 ton block, it doesn't make much of a difference to forge it the rest of the way. One of the worst arguments I have ever heard for why damascus is "the best" is that it is "more forged" than regular steel.

All that being said, I COULD be completely wrong, so do a good scientific test, and maybe this subject is worth revisiting.

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This argument has gone on since Material removal methods came on the scene and wrought iron was still a key player..When it had a section cut out of the side of a bar, it would peel off.. Not a great thing..  

While technically a  properly forged product will have an increase in ability to withstand pressure if it is applied across the grain structure (sideways)..   There are not a lot of people doing proper forgings..  I know I will catch fire for saying this..  I'm not saying there aren't a lot of great smiths or great products forged out there. What I'm saying is a lot of forgings now have disrupted grain flow..  I'm just as guilty since i don't work with Wrought iron enough anymore and get sloppy because modern steels can be worked all crazy like and still have a working product.. 

I go back to wrought iron and how it has to be forged, punched, cut, slotted etc, etc because of the inherent grain structure which is totally visible while being forged and if you go against that grain structure it will yell at you.. 

Most steels today are cast before rolling and if rolled will have a defined grain structure in the bar..(Casting will also setup a defined grain structure)  It's part of the process..  If forged properly it will keep that grain structure in a straight pattern. Straight  relative to the central grain structure.. 

If you have ever worked a large section of steel and have seen the inside portion stay where it is and the outside edge of the steel cup over the center.. Well this is creating a grain slip and will show a grain structure at the part between the fast moving and the slow moving materials like a glacier moving over the earth.. 

One of the key reasons the Japanese forged their blades the way they did is the materials were of poor quality..  The repeated welding and hammering refined the metal so it became a usable product with known qualities..  People are still doing it today with vintage type smelting furnaces.. The steel that comes out would be useless without refinement.. 

In the old days it was all about producing better steels for better weapons.. Wootz,etc, etc..  and then the largest change is when cast iron could be changed to steel. It made steel super cheap to produce.. 

One could argue the extra performance of correctly forged vs ground/stock removal would that performance ever be recognized physically by someone if it reaches that limit.. More than likely not..   I can say.. That it's only when items are pushed to the extreme that the margin of one vs the other might be realized..  

 

The extremes or in a laboratory environment where they can test the difference would be more than likely the only tell tale signs..

For all the Nin-gu I used to make I used to test everything to my body weight and intended purpose..  Everything only had the needed strength for it to work 100% for me.. Someone with bad technique or weighed more the item would fail..    I can tell you the items that were forged could be made smaller than the items that were machined..  

 

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Wrought iron is actually a composite material and the way the ferrous silicates are distributed in it makes it work very different along the axis as opposed to cross the axis. (Late in the game you got such things as the Byers bidirectionally rolled plate to try to address this issue, I have some and it's funny stuff as the ferrous silicates are "platy" rather than acicular.

Packing was done to refine grain size when grain size refinement was handled by forging and particularly needed for simple wrought iron derived steels that forged at wrought iron forging temps tended to have issues with grain growth. Modern allows you generally don't have the time spent at higher temps like wrought iron and  simple normalization cycle(s) will refine the grain down. (as a good example take a file, heat, quench and break off the tip and look at the grain, now heat to almost burning temp, let cool slightly and quench and break off the tip. Now normalize the file 3 times and do a quick heat and quench and break off the tip. You should see a progression of fine grain, coarse grain, and fine grain again---with NO FORGING, just heat treatment.)

So when folks talk of using a centuries old technique designed to deal with problems with centuries old materials on alloys that are only decades old and are designed to not need it....well selling stuff tends to be a lot about hype...

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Just My two cents worth, When bending a high strength steel like bissalloy in a press brake the full size sheet when delivered from the steel mill/supplier  has a grain direction marked on the sheet and when bending it you should bend across the grain so there must be something in the grain argument Cheers Beaver

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23 minutes ago, ThomasPowers said:

Is it delivered cold rolled or other work hardening process?

Thomas

I would guess it is hot rolled and them heat treated its probably some secret squirel industrial process. Thinking about it the rolling process would make any grain move along the long direction of the plate. Cheers Beaver PS I can remember watching that vid thousands of years ago when doing my apprenticship

 

Maybe it depends on to what extent it is heat treated ie what temp its taken to after rolling?

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4 hours ago, ThomasPowers said:

Wrought iron is actually a composite material and the way the ferrous silicates are distributed in it makes it work very different along the axis as opposed to cross the axis. (Late in the game you got such things as the Byers bidirectionally rolled plate to try to address this issue, I have some and it's funny stuff as the ferrous silicates are "platy" rather than acicular.

Packing was done to refine grain size when grain size refinement was handled by forging and particularly needed for simple wrought iron derived steels that forged at wrought iron forging temps tended to have issues with grain growth. Modern allows you generally don't have the time spent at higher temps like wrought iron and  simple normalization cycle(s) will refine the grain down. (as a good example take a file, heat, quench and break off the tip and look at the grain, now heat to almost burning temp, let cool slightly and quench and break off the tip. Now normalize the file 3 times and do a quick heat and quench and break off the tip. You should see a progression of fine grain, coarse grain, and fine grain again---with NO FORGING, just heat treatment.)

So when folks talk of using a centuries old technique designed to deal with problems with centuries old materials on alloys that are only decades old and are designed to not need it....well selling stuff tends to be a lot about hype...

For starters while part of the information you shared I would totally agree with, part of it from experience would say "Hog wash".. LOL.. 

As for grain growth of over heated carbon steels well heck yeah..  Improper heat treat will always show a larger grain growth.. And FYI.. You don't have to do 3 annealing sessions to get the grain growth to come back down to a decent size.. Firstly why would you over heat the steel and then harden it anyhow??????  Just to prove a point?

Anyhow,  When I talk about Mystery metal and proper hardening and testing.. Grain growth is one of the tell tail signs if the grain is to big that you quench temps are to high.. Simply quench at a lower and lower temperature till you get a nice pearlesque surface when the piece is fully hardened in the cracked off piece..  It's a no brainier unless you are using a high alloy steel..  some high alloy steels will show very little grain growth but will be damaged beyond use no matter how many times its been annealed. 

Grain growth when hardening vs grain structure from forging are 2 different things..  

Again the argument can rage on for years.. But if that were the case forgings would be the same size as cast.  With that being said, because of the ability to cast very high quality parts nearly to correct size with minimal finishing it's gained dramatically for high performance items like engine cranks and other items that were traditionally forged..

I'll still pick forged vs cast any day..   Of course a messed up heat treat doesn't matter whether it's cast or forged..  

The packing or wrought iron is useless unless you are making an item to act as a spring.. Yes I've made wrought iron springs.. Each spring lock I have made is cold forged wrought iron or mild steel 1018..   This cold works will produce a spring that will last for years and years.. And while it's not as robust as a carbon steel spring in it's proper application it works wonderfully.. I have spring locks out now that get daily use that are 30+ years old.. 

I guess it will have to come down to doing a whole bunch of forgings then harden them, cut them in half then micro polish and acid etch to make some happy.. 

Won't be me doing it as for the most part today it's trivial..    Someone should produce a show on :forged vs cast vs stock removal..  I'd watch it.. 

As for packing high carbon steels I experimented with it over 30 years ago.. Especially on cold chisels and rock cutting chisels..  I did notice that when a chisels edge broke it would fracture off the side vs a chip..    I decided it wasn't worth the time..   Really as I have matured as a Blacksmith I just started doing what was the fastest and what gave me the results I was looking for.. 

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The example I gave was a simple experiment anyone could run to show how normalization could refine grain size. I learned it from a metallurgist/knifemaker as a demo on grain growth and modern methods of dealing with it vs packing. (And Normalization is not annealing! Though SCA armour makers often call it so...) 3 is a reasonable number as it's a diminishing returns deal: 1 time does the most work, 2 times catches most of what was left and so on; but after 3 you really are not gaining an noticeable amount of improvement---for most alloys.

So can you tell me exactly what was hogwash?  Perhaps I worded something poorly.

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47 minutes ago, ThomasPowers said:

The example I gave was a simple experiment anyone could run to show how normalization could refine grain size. Guess I better tell the metallurgist who showed it to me that it's hogwash. And Normalization is not annealing. 3 is a reasonable number as it's a diminishing returns deal: 1 time does the most work, 2 times catches most of what was left and so on; but after 3 you really are not gaining an noticeable amount of improvement---for most alloys.

So can you tell me exactly what was hogwash?  Perhaps I worded it poorly.

Read it again. I didn't say it was all hogwash.. I said parts of it was hogwash..Or else all the stuff over the last 40 years about forgings is garbage and all the other engineers where wrong.. 

  The examples you have here are true.. Its like anything in blacksmithing or anything else for that matter... 

Doers, sayers, and thinkers..  

Scientifically Or from an engineering stand point there is always the optimal way to do something..(Engineers figure it out, that's what they went to school  and get paid)..  This optimal what ever is usually a best case scenario If X, Y, and Z are in alignment then you can expect a certain result..  Or can you... Just because it's engineered doesn't mean there aren't failures of the theory or procedure..  UM Titanic...   

As for your metallurgist friend, I'm sure he is smart as the dickens and from everything I have ever read or experimented with,He's not wrong, never said he was.

I was in school for engineering myself.. Anyhow, The point is while there are exacting standards and you can be scientifically or engineering superior it doesn't mean they can turn out a decent product.. Sure they can tell you what the proper sequence is or how a structural panel is supposed to be welded. How many times have their suggestions failed and then have to re engineered???? ..  Also how many times in the real world does anybody follow anything to the exact letter.. It's nearly an impossibility not only from a Monetary stand point, but also for a put in use stand point.. (That's why we all need liability insurance instead of a hand shake and a promise).. 

Anyhow, the original question/thread is/was on "heat treat, and grain structure of forged vs stock removal and how this effects grain" is what I had mentioned and made a response about.. 

Also the little film gives a good overview but doesn't actually talk about how the matrix changes the layout going  from pearlitic to martensite, or Banite.. etc, etc.. It's actually the way the molecules re-orientate when hardened that makes the steel have a ridged matrix and this effects grain boundaries and yes I can get out my metallurgical books and look up all the little didtiy's and engineering jargon but I'd rather not waste my time.. 

So,  I still believe that my original statement of forged vs cast vs stock removal stands..   There are 2 grain structures and they are distinct from each other.. One is a metamorphic and one is mechanical..  The mechanical structure of forging and grain structure alignment stays even in heat treat.. 

The grain structure of (brain farting with names so I'm going to make them up) polyphasic vs cubic molecule orientation (hardened steel) ( it goes from a polygonal, jagged edged molecule into a square orientation and thus stabilized) does change during heat treat or normalizing or annealing and it's this molecular reorientaton that changes with each type of heating and cooling.. 

It's only been 30 years since i studied this stuff, and I'm to lazy to look the names up. But I can still see the pictures of what they are supposed to look like at a molecular level or at least how they were drawn.. Personally I like the old book on metallurgy from the 20's.. 

 

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Ferrite at room temp is body centered cubic; Austenite above critical temperature is face centered cubic.  (I always remember that by thinking of my core of my body and rising up to my face, So as temp rises you go from BCC to FCC. I came this way through geology so remembering crystallography applies to metals too)

JLP you may notice I went back and edited my post as I felt it wasn't as clear as I meant it to be.  Re engineering, my Father said that every engineering equation has to have a $ sign in it somewhere!

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In the 20th century films on closed die forging, grain flow is mentioned as being an important part of die design. However, I don't think that I ever heard grain flow defined as regards steel. I read some time ago in an old metallurgy book that grain flow had to do with entrapped slag inclusions and trace elements of phosphorus and sulfur along the grain boundries in a lengthwise fashion on an as-purchased bar.  I asked myself, wouldn't that affect the boundries adversely?

Questions arise. When forging at the correct temperature, the grains move and change shape somewhat, but the boundries are retained. I think that there is a grain restorative process in hot work where the grains don't get permanently "flattened" and elongated and stay that way. In cold work maybe, yes, but not in hot forging. I think that I'm asking for a fair definition of grain flow, and I'm asking just how important it is in closed or open die work, as well as hand forging.

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 Chalk it up to "To much caffeine"

 

Well, maybe the books I have are wrong.. All the acid etched cranks and gantry hooks showing a definitive grain structure..  Who am I to say because I never did any of the experiments...

And the argument rages on..   "forged vs cast vs stock removal"..       Just like a tootsie roll lolipop.. How many licks does it take?   . 

Personally I don't have an invested argument as to forged vs stock removal.. I can say if that is the case than how many engineers were wrong in the last 100 years or more..   Wow, just dropped a doozy.. 

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On my way to work today I was going over this thread in my mind.. Also the whole of blacksmith scene..     At that moment I started to realize how Rip Van Winkle must have felt.. 

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So many aspects to this: one thing is that a lot of people rely on old books/tales many of them written by people who don't know the background science or include a few whoppers in them---Theophilus in 1120 A.D. has a LOT of great information on doing the studio crafts of the time, and then he includes that bit of softening quartz for carving by burying it in a chicken's chest... One of the more famous "books that started the modern smithing movement" was written by a person who wasn't a smith and sometimes the old smiths telling him stuff slipped in a fast one.

Another aspect is that the basic materials of smithing have changed over time: wrought iron, blister steel, crucible steel, Bessemer/Kelly steel: mild steel and now A36 remelt steel.  The are all based on Fe; but the differences cause issues.   Shoot early smithing works go over the materials of their day and what they are good for and how they have to be worked---Moxon's "Mechanicks Exercises", published 1703, mostly written in the last half of the 1600's has a list of where wrought iron came from and what it was therefore was good for making. The usually include testing methods for the metals too as pretty much all iron/steel was "mystery metal".

I've already mentioned the "hype" aspect of folks trying to make a living selling stuff. I've been amazed at how interested some folks have been in some of my historical experiments blades---quenching in blood (needs to be fresh!), quenching in urine (such an amusing smell!), etc and so on. ("Sources for the History of the Science of Steel"  includes a very amusing list of renaissance quenchants that were supposed to improve your steel by their use...)  Hard to get many people to understand that pattern welding does not guarantee a better blade and may actually be much worse than using a monosteel correctly handled.  (or the persistent belief that the folding and welding cycles used on Japanese blades increase their carbon content when in reality they *DECREASE* it!)

I'm not a Metallurgist; but I have friends who are and have never had any issues dropping by the local University and buttonholing one and asking question when I run across something strange, (and at least one time getting a plaintive "Why aren't you in my classes?!" after I gave my reasoning for what was happening in a piece of wagon tyre I had forged into a spatha. Wild grain in it---looked like hubble photographs---between very large grain areas and very fine grain areas. As we were in the mountains; I postulated extreme work hardening overlain on too much work at too high temps forging the tyre, perhaps multiple welding ops on it during a rough life. I forged minimally and at low temps---for wrought iron---and so created grain renucleation intermixed with overly large grain areas)

When I read the very old books I get the urge to try out what they are saying and see if it's true. Sometimes it is; but for very different reasons than the original author thought.

TLDR: old curmudgeon is rambling again; probably too much CO in his diet combined with slamming his head on the concrete too may times...

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21 hours ago, Anachronist58 said:

I thoroughly am enjoying this debate from my place at the shallow end of the pool........

 

On 3/29/2017 at 11:47 AM, ThomasPowers said:

So many aspects to this: one thing is that a lot of people rely on old books/tales many of them written by people who don't know the backg .............. TLDR: old curmudgeon is rambling again; probably too much CO in his diet combined with slamming his head on the concrete too may times...

Thomas,  I'm to old and to tired to even try to give a reasonable run for the money.  I have books from Bethlehem steel, and a few others but since What I am doing works. " I don't bother"  . I'll continue..  I'm still using knives and stuff I made when I was 10.. I have punches and hot chisels and swords over 30 years old which shouldn't work because i didn't follow the rules and used mystery metal.. 

As for A36 it works ok.. Welding it is a little different but once figured out it's just fine..  Really I think it comes down to what is important to the person.. 

I used to be one of those people who used to read everything they could and practice it both in hand and in conversation as to the merits of this vs that with the few smiths I did get to know...  Also could tell you the 15 different chisel names used before milling machines and such came on the scene.. have made files by hand and hacksaw blades... My point is this far along in my life I've forgotten more than I know and while it is kind of fun for me to share who made oval eye hammers.. or why wrought iron is a great learning tool and why mystery metal is awesome.. It's because I don't think a smith or newbie should be limited by what someone says is "correct or not"..   Just there are better ways, or faster ways, or easier ways..  

I'm self taught as a blacksmith,  spent 3 years learning the farrier trade and then went out and figured out on my own why horses feet have so many abnormalities and simple ways to cure most of them.  I'm not a restless soul.. I just don't settle for what status quo dictates as the norm..  

It's part of my character.. Never give up, never surrender..  Merely bend or move to a better position, recoup, rethink, apply.. Rinse and repeat..    Anyhow, now I'm happy just doing what I do and I work with all sorts of steels and alloys( 4140, A2, D2, S7, H13, W1, 5160, HSS) copper, bronze, brass, aluminum etc, etc. 

I still stick to my original statements and while technology has come a long ways and while much of it is assumed knowledge based on example.. No one can really say since it's in the past..   :)  Also on that note.. Time and time again.. Engineers change their minds, make mistakes, and just plain old mess up..  Revisions and reprints.. time and time again.. Well yah, duh it's called a learning curve..  Well this didn't work so we should do this instead..     

Sometimes good things come from it. Sometimes they don't..    

Anyhow,  Thanks for you input and adding to the knowledge pile..   It's all good when someone can benefit in the end..   and it's been a pleasure and you certainly know your technical goodies. :)

21 hours ago, Anachronist58 said:

I thoroughly am enjoying this debate from my place at the shallow end of the pool........

NICE!!!!!!

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Hi Thomas. First off, apologies for re-posting your entire post, I'm yet to figure out how to isolate part of a post and quote it without re-posting the whole thing. Anyway, in re to your mention of Sources for the History of the Science of Steel... On your advice some months back I did secure a copy and as you said it was "a hoot". I should have inferred from the title that it would be a compilation but that escaped me until it arrived. I already had copies of De la Pirotechnia, and Magiae Naturalis Libri Viginti but the rest of the material was new to me and contained many grins. Of particular note were the references to the harvesting of morning dew from particular plants. This presents a stumbling block for me as I am a night owl. I have no issue with quenching in "fresh" blood, but I am not getting out of bed early enough to harvest dew! 

My favorite tidbit is in the preface to the Thirteenth Book of Natural Magick. della Porta quotes Pliny, "of iron there are made the best and the worst instruments for the life of man" It makes me think of the innovation brought about through the forging of simple things. Magick giving berth to Science. As a blacksmith, not a scientist, I am mostly content with results even if I don't understand the cause and effect. The science is interesting but the magick is infinately more so! 

Thank You for the recommendation and for adding another obscure text to my collection!

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56 minutes ago, TwistedCustoms said:

Hi Thomas. First off, apologies for re-posting your entire post, I'm yet to figure out how to isolate part of a post and quote it without re-posting the whole thing.

Click "Quote" and then edit the quote. Also, you can highlight the part that you want to quote, and a little "Quote this" gizmo should pop up. Click on that, and Bob's your uncle.

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or, after quoting, Highlight the parts you dont want , hit delete like I am going to do now to your posts.   Many people  still pay by Kb, now minute, so it is costing them wasted ,only to have to deal with full reposts of text and photos. please be considerate of others.

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