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problems for etching wootz


qiangluo
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Hi everyone! i am new here.

 

recently i have been intrest in wootz steel. i am too lazy to build up my own gas and coal furance for smelting. so i took a shortcut and used labarotory equipment. the ingots was made by vaccum induction melting furance, 30kg ingot was made after cut off the top slag. the ingots was forged into bars by 650kg air hammer at 1070~800°C,then hot rolled the bars at same temperature into four sheet of 12mm thickness. the above steps was done in labarotory and in a forging factory. then i got several blades forged from these sheet. the temperature of hand forging progess is between 950~750°C. it might be a little bit lower or higher since its controlled by eye. finally i got them polished to 1000grits finish.

 

and now i kind of stucked at etching. i tried 3%~5%HNO3 at room temperature for 5 seconds and 20%FeCl3 at room temperature for 3 mins. both seems cannot bring up the banding structure very clear. well, you can see the bands there, its just not very clear and you have to go close and look. here are some attachments pictures i got from both bars and blades.

 

due to the forging and rolling progress, the banding structure seems all followed one direction. and looks kind of too simple, well its the first time i had tried this. i didn't even expect to get any pattern at all. fortunatly, i got the pattern, but the etching won't show it very clear. so do you guys have any etching experience that is able to share?

Picture 033.jpg

wootzblade.jpg

wootzblade1.jpg

wootzblade2.jpg

wootzblade3.jpg

Edited by qiangluo
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looks about right to me...

 

well, in photos it looks ok because it was under the flash light's reflection. but without using a flash light the pattern is not so clear unless you look at it from an angle.

Edited by qiangluo
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Hello

 

you have picked a steel that has a reputation for being difficult !

 

I would stick a little closer to historical chemistry, it is easier then to figure out how it should react with the etch. (especially with V and some P )

 

-when you were belt grinding, did you see a wootz pattern in the un-etched bar? Generally, a good wootz will show its self as your grinding and you can see enough of the pattern to know what to expect after the etch !

- if you didn't see it, then the degree of difficulty to etch goes much higher !

 

- also, you should know that wootz can be very unpredictable... sometimes it becomes a poorly etching steel for unseen reasons... it just happens

 

 

how did you polish the bar? the higher grit polish should be done with sharp abrasive and with an oil or water lube. -- this is done to avoid burnishing or smearing the surface of the steel, which can lead to a surface that resists the acid

-

-- how did you degrease the bar ?... dilute nitric is an excellent etch for wootz but it is extemely fussy about having a oil/grease free surface. If any oil or grease is on surface, a poor etch result will occur and potentially contaminate the etch solution !

- that is a very critical step, and it still catches me every once and awhile .

 

 

 

I would like to add that although a 30kg ingot, massive powerhammers, and rolls, are extemely interesting ways to produce steel in a modern fashion, they are departure from the nature of the original wootz crucible steel. The original was a small crucible steel with a typical degree of reduction under small hand hammers (as far as i know )

- if you introduce several new variables to the equation, it may give you a much different material than was produced in ancient times !

 

eg... the percent reduction of a very large 30kg ingot down to the thickness of a blade is much much more than reducing a 2kg ingot to blade thickness ! what is left of the original structure ?

 

sorry to be complicated, but nothing is simple with wootz

 

 

Greg

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Hello

 

you have picked a steel that has a reputation for being difficult !

 

I would stick a little closer to historical chemistry, it is easier then to figure out how it should react with the etch. (especially with V and some P )

 

-when you were belt grinding, did you see a wootz pattern in the un-etched bar? Generally, a good wootz will show its self as your grinding and you can see enough of the pattern to know what to expect after the etch !

- if you didn't see it, then the degree of difficulty to etch goes much higher !

 

- also, you should know that wootz can be very unpredictable... sometimes it becomes a poorly etching steel for unseen reasons... it just happens

 

 

how did you polish the bar? the higher grit polish should be done with sharp abrasive and with an oil or water lube. -- this is done to avoid burnishing or smearing the surface of the steel, which can lead to a surface that resists the acid

-

-- how did you degrease the bar ?... dilute nitric is an excellent etch for wootz but it is extemely fussy about having a oil/grease free surface. If any oil or grease is on surface, a poor etch result will occur and potentially contaminate the etch solution !

- that is a very critical step, and it still catches me every once and awhile .

 

 

 

I would like to add that although a 30kg ingot, massive powerhammers, and rolls, are extemely interesting ways to produce steel in a modern fashion, they are departure from the nature of the original wootz crucible steel. The original was a small crucible steel with a typical degree of reduction under small hand hammers (as far as i know )

- if you introduce several new variables to the equation, it may give you a much different material than was produced in ancient times !

 

eg... the percent reduction of a very large 30kg ingot down to the thickness of a blade is much much more than reducing a 2kg ingot to blade thickness ! what is left of the original structure ?

 

sorry to be complicated, but nothing is simple with wootz

 

 

Greg

 

thanks Greg.

 

i have thought about using V too. but too big the ingots i got. i used 40kg vaccum induction furance, it comes out a 30kg usable ingots after removing the top slag hat. and forging such big ingots required soaking temperature at 1100°c. i was worry about VC dissolves during that soaking time. so i used more stable Nb. i have to avoid using p too. i was worry about adding it will increasing the difficulty of forging progress. alas the ingots is kind of big.

 

and yes i could see the pattern during the grinding, however not very clear too.

 

i used belt grind it to 600. then switch to SiC sand papper finished 800~1000 polish, and i used water lube. finally i used some dish washing soap to clean the bar.

 

and yeah, i found that this methode i have done might have too much of redution, the fiberous of banding structure was pulled too thin and too long in one direction. next time i would try a 6kg furance. or i can get a 30kg ingots still, but then WEDM it into many 2kg bars for hand forge. hope it will work.

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Looks like a fun project. And looks pretty as well.

Did you put any through your V notch impact test?

 

How difficult was it to hand forge to a blade from the rolled bars? Can we see some pics of the whole blades?

 

I remember reading some posts a bit ago, talking about mass producing wootz. I would bet your 12mm bars would be a big seller on eBay.

 

I have a feeling that even wootz "like" steel, that was workable, would be a big seller.

 

It must be fun to have that big equipment to play with. Cool!

 

Mark

Mark Green

 

I have a way? Is that better then a plan?

(cptn. Mal)

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Looks like a fun project. And looks pretty as well.

Did you put any through your V notch impact test?

 

How difficult was it to hand forge to a blade from the rolled bars? Can we see some pics of the whole blades?

 

I remember reading some posts a bit ago, talking about mass producing wootz. I would bet your 12mm bars would be a big seller on eBay.

 

I have a feeling that even wootz "like" steel, that was workable, would be a big seller.

 

It must be fun to have that big equipment to play with. Cool!

 

Mark

 

Mark,

The auction buyers are becoming more sophisticated and sales are a very dynamic (rapidly changing) phenomenon( as is our economy ) . We have seen a famous wootz maker only selling his blades at a so so rate..who knows why ( it appears he has just adjusted to a different market) . I have seen ( from a distance ) a "wootz" blade by Paul Chen on the auction site,..

Rick and Niko have worked with very big ingots (Ric's) , I do not remember how it went.

 

The bottom line is, Wootz is here to torment us. Maybe those surviving the torment over time will earn a wootz patch to pin on their uniforms.

 

Jan

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Hi Mark

 

i like Jan's take on this ! so true

 

Mark, just as you have outlined a basic plan to mass produce wootz, if it could be so simple ? I believe you hit the main reason why wootz fell out of popularity and use ... the material does not lend itself at all to efficient production .... especially when you compare it to normal carbon steel, which is easily produced and quickly made into knives !

- it was fine when wootz was competing with bloom steel, then it was in a similar league !

 

this is basically why you see it produced only in very small quantities, it is technically a dinosaur that went extinct prior to industrial age.. <_<

 

 

Greg

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Oh yes, I totally agree. And I'm sure as hell will not be mass producing any. But, it looks like Qiangluo may have the tools to try it.

 

If anything, I may chase the rabbit, to dig for dinosaur. In small amounts. :wacko:

 

Maybe earn a patch for my uni if I'm crazy enough. :D

Edited by Mark Green

Mark Green

 

I have a way? Is that better then a plan?

(cptn. Mal)

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well. one thing i must say here. i am not a massive productor nor working for one. and you need not to worry. none of these massive producted wootz will challeng handmade one on the knife markets. at least none get out from me. btw i was the same person posted massive producted wootz method on bladeforums, its just to share the experience not to sell any. hammerfall, that was me. i guarantee that you won't see 12mm wootz bar on ebay from me.

 

40kg furance is what i can get easier access without running into other people who need to use the furance. then ingots is sent to a forging and pressing factory after homogenizing annealing to get it forged and rolled into sheets, it just need more experienced people to get this step done. rolling is kind of hard, it was forced to giving higher temperature. resulted a thick oxide layer outside. the structure can be refined by following hand forge.

 

and forging a 12mm bar is not hard at all. acctrully, the forging temperature of this steel is kind of forgiving. and no, i did not even think of any impact test, steel with this carbon content kind of limited its toughness in hardened states. i am not sure bainite can transform in this steel, i still salt bathed one. i am going to test it as soon as i get access to the lab again.

 

here, i got a video of a blade that has a hamon, it was kind of poorly done. but my goal was to see if this one can have a nice hamon. sorry i had to delete all sounds since i used chinese screaming too much F and S words in this video, trust me you do not want hear that.

 

maybe i should change my loaction to old address in us, so that no one mistake me for a massive productor.

hamon on wootz blade.mpg

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i knew that my chinese name plus what i was saying will make people worry about massive production will overrun the market lol. you have my words here that you need worry not about me.

 

for i do not making knives for life, and do not planning doing it. its just my hobby. i am not selling steels, at least not wootz for sure. it has not much advantage(if any) compares to many modern steel in the industrial using.

 

my everyday life is mostly dealing with mines, coal and rare earth such. otherwise, why do you think i quit my confortable life in america and came back here lol?

 

the very first motivation pushed me doing this was because too many people especially some of the antique sellers here always talking about wootz cannot be remade by modern way. so i took my part in and did all these to simplly prove them wrong.

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well, after all that explainations. may i have some more advices about etching? how to make color contrast look better?

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Bonjour Q

 

Hah, i think you also misunderstand, no one is scared of mass produced wootz because it doesn't work that way.

.... it would be same as mass producing tamahagane... cost is extremely high (labour and old process, and market is very small

-look at the Hanwei wootz, it is mass produced, and look at pattern...its just some regular banding in the barstock they have...that they've etched to show... no one is fooled by that, it looks absolutely nothing like the ancient wootz.... so no fear !

 

back to etching... with nitric etch, you have the best window into the steel !

- its not like putting on makeup on ugly girl, to make the appearance look better :lol:

- dilute nitric will give contrast that is needed

 

 

welcome to crucible steel frustration

 

Greg

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Greg, I think you hit the nail on the head with the ingot size. Starting from an ingot 10-20 times the size of a traditional egg, there's obviously a lot more rolling, forging, etc. so any grain is going to be running very much parallel to the direction and be very refined, meaning what you may have might be a UHC steel but it's not going to have the look of the traditional stuff. I've seen some wootz blades look similiar to what this fellow ended up with in spots near the tips or elsewhere where the piece was probably forged very thin with little grinding.

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thanks again greg. my appology if my words offended anyone. its just everytime i introduce a new method or new mats in a blade smith forum, people almost instantly think i am a massive productor. it happened before almost everytime.

 

and for massive production wootz, i figured that myself. direct forged and rolled wootz of large ingots pretty much cannot have the lively pattern like the traditional crucible steel due to the large rate of deformation. and yes, doing this is like burnning money. well, it acctrully had very few labor work to be done tho. most of the work was done by mechines except hand forging 12mm bar and grinding.

 

i had 30kg ingots, that really cannot count as massive production. still the pattern all looked too simple, too straight due to large rate of reduction. as you might have already seen in the video i uploaded earlier.

 

WEDM the ingots into 30x30x200mm bars after homogenizing annealing might work since there isn't any reduction. then start hand forging from there. i am going to try it next time.

 

i used 3% nitric, and it turns out to be the look in that video. guess i will try with 5%~10% nitric.

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Hi qiangluo,

nice attempt that you made, so here are my remarks:

for a 30 kg ingot with 1.5%C and Nb or V in it 1100°C (it is the beginning range for dissolving the carbides!)"soaking" may be too low for dissolving the carbides before forging cycles - when a 1.5kg egg needs 1 to 2 hours of dissolving time at nearly 1200°, how long did you try - just to make sure you really dissolve all of the inner matrix?!

then about forging: it always seemed to me that forging wootz recommends forging of all sides, sometimes even forging a piece back into the "old" shape to improve the banding

so if you give the big cake to machine handling and it is rolled, it looks more like streching the stuff in one! direction, so the result is poor banding (which can be seen better when hardened by the way)

and is does look to me kind of coarse, too dendritic as my friend once said to me

 

but all of us would probably love to get a present of 2-3kg of your testmaterials for further resmelting B)

 

so when you find a facility that will do the forging and rolling in a more sophisticated way, or maybe you could give the ingot 60 - 80 heat treats before the process, you might receive more banding of the traditional kind...

 

I find it most interesting what you are able to do in a big, industrial way,

when I look at my small smelter <_< instead

so go ahead

 

and of corse, about etching:

try 5 to 10 % nitric in alcohol (nital)

which works better when it is warm (not more than 45° pls!!!)

but ferric works better when warmed too

and my daughter always worries about me: use the good gloves, where is your eyeprotection?! - she is good to me and a chemist to be...

 

best regards

Jokke

 

PS

and try to come to the wootzsymposion in Gembloux (BKS knife show)in Belgium in November this year

Edited by Jokke

Jokke

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hi jokke.

 

if i remember right the first soak was at 680°C for 3 hours, then slow heat to 1150°C and soaked for another 3 hour. start forging at 1100. i did not really check at what temperature and how long the carbid all dissolved. but i did a caculation for %v and %c dissolving temperature tho. the fomula cannot give the exact number but it tells a approximate value. the caculation result was kinda close to the soaking temperature. so i used a little bit of Nb.

 

60~80 cycling!!!damn, that would cost really a lot of time heat treating a 30kg ingots hahaha. and yes, a more sophisticated way of forging and mechining would be a better option for me.

 

also thanks for that etching suggestion. i will try a warmed etching tomorrow.

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alright, i got a new one. it was still forged from the 12mm bar. but was given addition deformation on oposite directions. and it came out like this, i would say it looked a little bit better this time. the little black nodes are rusts. i used salty water while polish, and didn't oil it after polish. and in the morning it get some rust

wootz.jpg

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seems to have a finer structure than the one in the video

why don't you try some x'ses or v's or big O's in the sense of cutting into the steel before forging it blank,

maybe you get some nice bandings and changes in the structure, too

 

saltwater for a fast quench is OK, but hard on the steel

you have to oil it after washing off the grinding rests though..

 

regards

Jokke

Edited by Jokke

Jokke

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by the way: why do you use saltwater when polishing? Never heard of that before...

salt will interfere with the etchant, too

to me it does not sound like a good idea,

 

how are you coming forward?

any new tests?

 

greetz!

Jokke

Jokke

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