Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 5, 2008 19:37:20 GMT
Hi Everyone, I need some help! The steel I use is 0.8% carbonsteel. Notice: The first two pics are from the second blade and the three last of them are from the first on, but both I made the same way and both are the same steel, I just didnt got any pictures of the "clay" proces for the first one and no pics of the broken second one either (I hope you all understant what I mean ) I tried quenching my tanto few days ago and it ended up with 7 cracks. After I had forged and grinded it to a proper shape I roll some newspaper on it and soak in oil until its completely absorded to the paper, then I heat it to exactly 900degrees with 2hours heating and other two hours keeping it in 900degrees then just let it cool slowly(with furnace we have in the metal art school Im in) to normalize it. And instead of clay I use firesealent (fireproof until 1200celcius) and I spread it to the blade like this: When it has dryed 24hours, I put it back to the furnace and heated up to exactly 830degrees with one hour raise and keeped it in 830degrees for one hour, then I quenched it to about 35 - 40 degrees water and the result after remowing the fire sealent looked like this: (After some grinding, I think that line is actually the the hamon) In this picture you can see the cracks So I was thinking If someone could tell me what went wrong and what sould I do next time. PS: I'm not so good at english so there might be some misspelling:D And also I'm just a beginner bladesmith who studies in IKATA (Ikaali's institute of arts and crafts, special metal) for the second year. Joona
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 5, 2008 23:27:38 GMT
Water is most likely the answer why your blade cracked. Your soak times and time up to temperature 850C, then an hour at temperature that is a long time!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 6, 2008 10:55:15 GMT
Water is most likely the answer why your blade cracked. Your soak times and time up to temperature 850C, then an hour at temperature that is a long time! Should I use oil? and how long do I keep it in the quenching temperature? What would you recommend?
|
|
|
Post by Dan Davis on Dec 6, 2008 15:10:16 GMT
5-10 minutes at the most.
Also, .80 is fairly high carbon content but without knowing the rest of the steel's composition we cannot really advise you about heat treating it.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 6, 2008 15:13:24 GMT
5-10 minutes at the most. Also, .80 is fairly high carbon content but without knowing the rest of the steel's composition we cannot really advise you about heat treating it. Well actually I dont know it either, but we use it to make knives from it and many has made pretty good ones too in my school. I'll ask my teachers about the steel if he knows something.
|
|
|
Post by Matt993f.o.d on Dec 6, 2008 18:00:19 GMT
A one hour soak time?! Blimey.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 6, 2008 19:16:48 GMT
A one hour soak time?! Blimey. I'we heard that heating it slowly and keeping it in the quenching heat for awhile it decreases the risk of shattering during quenching. Thats why. (PS: I dont use forge to quenching though its very important skill to learn, but I use it because I learn to regonize the color of the steel in diffirent temperatures that way. And then I can practise it with a forge)
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 6, 2008 20:56:07 GMT
I've read that a good long soak at just above lower critical temperature is of large benefit. This gives the steel LOTS of time to fully transform to austenite, without the higher temperature. That said, an hour still seems excessive.
If your steel is very high in manganese, or chromium this will affect the way you heat treat substantially. High percentages of those in the alloy (more than 3pts) will affect the nose of the time/temperature curve negatively for production of hamon. You can combat this by multiple thermal cycles from just above critical to air temperature (air cooled). I did 5 cycles on my 1060 which is pretty high in manganese at 7pts or so, and got a beautiful hamon. Holding the blade at the temperature you did for so long probably grew the grain, increasing the effect of the manganese and/or chromium, which would have contributed greatly to your cracking issues.
Another thing I'm surprised Sam didn't mention is trying an interrupted water into oil quench =). The current tanto I am working on needed to be heat treated twice due to me being unhappy with the hamon on the first attempt. It lived through both tries, and is a longer, and a bit narrower blade than yours it looks like.
Anyhow, hope this helps, and it's cool to see another new maker on the board =).
Cris
By the way...I'm a relatively new maker myself =). Take my advice and information as suggestions to do your own research! I'm repeating what I've learned and what's worked for me...but that doesn't necessarily mean it will work for you, your steel, and your setup! Experimentation, while sometimes difficult or unrealistic...will always be your best teacher.
C
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 6, 2008 20:58:15 GMT
Oh! One other thing...
Looking at your pictures...did it crack at every dip in the hamon? That's sort of what it looks like, and might indicate your clay application as a partial culprit. It may also just be the weak points where the other issues were able to exert their influence...but still =).
Something to take a look at!
Cris
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 6, 2008 22:11:24 GMT
Oh! One other thing... Looking at your pictures...did it crack at every dip in the hamon? That's sort of what it looks like, and might indicate your clay application as a partial culprit. It may also just be the weak points where the other issues were able to exert their influence...but still =). Something to take a look at! Cris Actually yes it did. And thank you for the tips, they are helpfull for me (and would be more helpfull after I have translated some words on my language (wich is finnish) I dont know for sure lol ) And I made a little mistake on the pictures Iwe quenched two tantos now and both had 7 cracks. The first two pics are from the second blade and the three last of them are from the first on, but both I made the same way and both are the same steel, I just didnt got any pictures of the "clay" proces for the first one and no pics of the broken second one either (I hope you understant what I mean ) By the way, the first tanto blade I'we ever made (a year ago) and quenched in the forge using this same firesealent I actually got a visible hamon but then unfortunately after the quench I accidentally dropped it and broke it And finally one more question, how sharp the blade can be sharpened before quenching, if I heat it in the furnace. I'we been taught that if you heat a sharp edge on the forge, it might burn and ruin the edge. And then again, one student in my school sharpens his knives very sharp before quenching and had pretty good knives. Joona
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 13, 2008 4:58:10 GMT
Having read all the post in this thread. I agree with everyone and yet disagree with everyone in some strange way. I guess I see this whole process in a much simpler term.
Just so you know that I am not pulling your leg Cris and Sam can vouch for me. I forge Japanese style blades. And maybe I am alone on this one but I only quench in water. Because I use W-2 or W-1 for my japanese blades. I do not use oil at all excpet on my 5160 blades or my O-1 blades.
It would seem to me that most are making the whole heat treat process to long and complicated.
Getting your blade to temp and soaking it for more than 10 minutes is about the best you should shoot for.
Try Satanite for the clay to apply to the blade. And before you apply the satanite, apply a very thin layer to the blade itself and I mean very thin, then apply the rest to make the hamon. This will help control vapor bubbles from forming on the blade and hindering your quench plus the thin layer of clay creates more surface area and will cool quicker.
I also quench at night lights out me, my music and my magnet along with watching the color in the steel.
So my advice to you is do not make it to complicated, look at it from its simplist form and go with that.
If you have any question please keep asking
John
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 13, 2008 9:28:00 GMT
Having read all the post in this thread. I agree with everyone and yet disagree with everyone in some strange way. I guess I see this whole process in a much simpler term. Just so you know that I am not pulling your leg Cris and Sam can vouch for me. I forge Japanese style blades. And maybe I am alone on this one but I only quench in water. Because I use W-2 or W-1 for my japanese blades. I do not use oil at all excpet on my 5160 blades or my O-1 blades. It would seem to me that most are making the whole heat treat process to long and complicated. Getting your blade to temp and soaking it for more than 10 minutes is about the best you should shoot for. Try Satanite for the clay to apply to the blade. And before you apply the satanite, apply a very thin layer to the blade itself and I mean very thin, then apply the rest to make the hamon. This will help control vapor bubbles from forming on the blade and hindering your quench plus the thin layer of clay creates more surface area and will cool quicker. I also quench at night lights out me, my music and my magnet along with watching the color in the steel. So my advice to you is do not make it to complicated, look at it from its simplist form and go with that. If you have any question please keep asking John Actually I dont use clay I use firesealent that hold up to 1200 celsius. And yesterday I tried to use oil instead of water and I actually got a visible hamon without any cracking. I think its easyer to use oil for a beginner like me. But thank you for the advice I appreciate it.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 13, 2008 9:31:19 GMT
Having read all the post in this thread. I agree with everyone and yet disagree with everyone in some strange way. I guess I see this whole process in a much simpler term. Just so you know that I am not pulling your leg Cris and Sam can vouch for me. I forge Japanese style blades. And maybe I am alone on this one but I only quench in water. Because I use W-2 or W-1 for my japanese blades. I do not use oil at all excpet on my 5160 blades or my O-1 blades. It would seem to me that most are making the whole heat treat process to long and complicated. Getting your blade to temp and soaking it for more than 10 minutes is about the best you should shoot for. Try Satanite for the clay to apply to the blade. And before you apply the satanite, apply a very thin layer to the blade itself and I mean very thin, then apply the rest to make the hamon. This will help control vapor bubbles from forming on the blade and hindering your quench plus the thin layer of clay creates more surface area and will cool quicker. I also quench at night lights out me, my music and my magnet along with watching the color in the steel. So my advice to you is do not make it to complicated, look at it from its simplist form and go with that. If you have any question please keep asking John Actually I dont use clay I use firesealent that hold up to 1200 celsius. And yesterday I tried to use oil instead of water and I actually got a visible hamon without any cracking. I think its easyer to use oil for a beginner like me. But thank you for the advice I appreciate it. I am a beginner as well Joona, and I've found a water quench for a short few seconds, then out and into oil is a VERY nice process to use. Your hamon with oil will not be as active or beautiful as with water. Also, you can (and will more often than not) get negative sori with the oil quenching. There is a video in the polishing link that shows the hamon on my recent tanto. That was quenched in brine (water, salt, and dish soap) then into oil. I wouldn't recommend brine personally to a beginner, but water and then oil might give you the safety you're looking for, while working the kinks out on why they crack on you. Cris
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 13, 2008 14:03:38 GMT
I am a beginner as well Joona, and I've found a water quench for a short few seconds, then out and into oil is a VERY nice process to use. Your hamon with oil will not be as active or beautiful as with water. Also, you can (and will more often than not) get negative sori with the oil quenching. There is a video in the polishing link that shows the hamon on my recent tanto. That was quenched in brine (water, salt, and dish soap) then into oil. I wouldn't recommend brine personally to a beginner, but water and then oil might give you the safety you're looking for, while working the kinks out on why they crack on you. Cris You mean like first dip it in water and then quickly in to oil to cool till you can touch it bare hands? My water quenched blades cracked after being in water like 2-3 seconds. And I noticed that negative sori thing, the tip of the blade curved just a littlle wrong way.
|
|
|
Post by Matthew Stagmer on Dec 13, 2008 17:42:56 GMT
Yea that is way too long of a heat soak. try leaving your edge thicker before HT.
|
|