deker Posted April 5, 2011 Share Posted April 5, 2011 (edited) So, I'm annealing some Damascus for a customer tonight and it's a large-ish piece (2 1/4"x1/4"x15"). Add to this the fact that my shop still doesn't have proper electricity, and the last lightbulb popped the other day, and I was working by flashlight. I decided to watch for recalesence in complete darknes when the piece came out of the kiln on a normalizing cycle. What an experience! I've seen decalesence/recalesence many times in the past, but never in almost complete darkness. It also helps that it was a large piece. Being able to see a dramatic brightening of the steel as the carbon fell back out of solution was just amazing. If you haven't done this, you really should try it. -d Edited April 5, 2011 by deker Link to comment Share on other sites More sharing options...
GEzell Posted April 5, 2011 Share Posted April 5, 2011 I always heat-treat in utter darkness, just the glow of the forge... I can spot decalesence this way, but I have missed the oil once. Moonlight helps in that respect. There is a primal purity to it I enjoy. George Ezell, bladesmith" How much useful knowledge is lost by the scattered forms in which it is ushered to the world! How many solitary students spend half their lives in making discoveries which had been perfected a century before their time, for want of a condensed exhibition of what is known."Buffonview some of my work RelicForge on facebook Link to comment Share on other sites More sharing options...
Christopher Price Posted April 5, 2011 Share Posted April 5, 2011 Been there, done that. http://paleoplanet69529.yuku.com/topic/26894/Decalescance The Tidewater Forge Christopher Price, Bladesmith Link to comment Share on other sites More sharing options...
deker Posted April 5, 2011 Author Share Posted April 5, 2011 I may try to do this again and get some video. I've done this several times with just the glowing of the forge, but this was different since I'm using a kiln now. The only light in the shop was from some LEDs on the kiln controller....MUCH darker than with the forge running, and on a dark night to boot. Sometimes it's the simple things in life that are the most fulfilling....or maybe work is just sucking this week, who knows? -d Link to comment Share on other sites More sharing options...
Dan Hurtado Posted April 5, 2011 Share Posted April 5, 2011 OK, newbie question time: What is decalesence? Link to comment Share on other sites More sharing options...
Richard Furrer Posted April 5, 2011 Share Posted April 5, 2011 (edited) When steel is heated to austenite it undergoes a crystalline change from body centered cubic to face centered cubic. This change requires energy and in endothermic (absorbs energy). When you slow cool the Austenite transforms to something else..in this case Cementite/Pearlite and Ferrite....so it goes from face centered cubic to body centered cubic...this is exothermic and gives off energy..which we see as light..or a reheating of the material just after this phase change. Some alloys show this very well others almost not at all. Mostly pure iron is not detectable when it does the change, but it does change. The steel I smelt seems to have a great "hang time" and shows this very well...not exactly sure why. Ric Edited April 5, 2011 by Richard Furrer Richard Furrer Door County Forgeworks Sturgeon Bay, WI Link to comment Share on other sites More sharing options...
Dan Hurtado Posted April 5, 2011 Share Posted April 5, 2011 Ah, thanks Ric. Everything is now illuminated. (Bad pun, sorry.) Link to comment Share on other sites More sharing options...
Richard Furrer Posted April 5, 2011 Share Posted April 5, 2011 Ah, thanks Ric. Everything is now illuminated. (Bad pun, sorry.) Illuminated indeed.............,but you have to move the blade to keep the light focused as the shadow travels. Ric Richard Furrer Door County Forgeworks Sturgeon Bay, WI Link to comment Share on other sites More sharing options...
Luke Shearer Posted April 5, 2011 Share Posted April 5, 2011 Ooooooh, Ive seen this before, but I always thought it was some annoying uneven heating or somthing. I like this much better than uneven heating . Really though this is pretty cool. Steel is amazing. “Then something Tookish woke up inside him, and he wished to go and see the great mountains, and hear the pine-trees and the waterfalls, and explore the caves, and wear a sword instead of a walking-stick.” Link to comment Share on other sites More sharing options...
Howard Clark Posted April 6, 2011 Share Posted April 6, 2011 It is an important key to understanding carbon steel and how it works. I like simple steel about .8%C because this is nice and bright. It is also remarkably visible in 52100 and low light conditions. Add anything much for alloying elements, and it goes all stealth on you and is difficult, if not impossible, to see. It is a favorite demonstration, and something just to enjoy, like a beautiful sunrise, or sunset. Whichever you prefer. I am a sunrise fan myself. Link to comment Share on other sites More sharing options...
Doug Lester Posted April 6, 2011 Share Posted April 6, 2011 I guess that I'm going to have to look for that when I heat treat the two knives that I forged from 52100. The only thing I don't like about heat treating during the late evening is that it makes it harder for me to see if the knife warped during the treatment. Doug Lester HELP...I'm a twenty year old trapped in the body of an old man!!! Link to comment Share on other sites More sharing options...
Alan Longmire Posted April 8, 2011 Share Posted April 8, 2011 I love it. By using this phenomenon you don't have to resort to a magnet or guesswork, the steel tells you exactly where it is in the transformation process. Natural magic at its finest. Link to comment Share on other sites More sharing options...
cdent Posted April 9, 2011 Share Posted April 9, 2011 As a rookie, I like to watch the phase change to get a little idea if my hammering is smooth and even. I think I can see blips and wiggles in uneven steel as the glow passes through. For me it flashes by kind of quickly in lower carbon steel like 5160, but it's very exaggerated in something like W2, at least the way it looks to me. I usually don't need full darkness, just a dark background and something that's throwing a little shadow. It's part of getting lost in a blade for a little bit, Craig Link to comment Share on other sites More sharing options...
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