Cracks Ahoy

T Blade

T Blade

Joined
Aug 25, 2003
Messages
1,466
The last couple of Saturday's I've been to IG's house (though he moves everytime I tell him I'm coming over). Two Sat's ago I hammered out a blade from a material some people call duedag, it's actually a flat thread rod which I've seen in 1/2" up to 2 1/2" dia.

After forging I put it in IG's hot box and last Sat. I went over rough ground it and figured I'd to a clay coat HT.

I've never had a blade crack on me until then. Kinda like I did it on purpose, Wa..Wa..Wally told me to use oil quench, but being thick headed and wanting to use water, well....a picture is worth a 1000 words :D

PICT2540.jpg


What you see here is a pic of the blade which has been magnetic particle tested using wet flourescent mixture seen under a black light. The green lines at the blade edge are cracks :eek:

If this blade wasn't clay coated it probably would have broken into several pieces.

I don't think that I'll water quench duedag anymore:cool:
 
Thats some high tech blade sluething you did there Larry.Mag particle....dont tell me you UT your damascus for inclusions :D ;) I'm saving my 2 1/2" duedag for power tools :eek:
 
When I was at IG's last weekend (when Larry did his water quenching) IG sent me home with an 8 inch section of duedag that I'm going to forge some hawks out of. Now I know to make sure to avoid the water quench =P

I've quenched 2 blades in water and neither cracked so far. One was my cable damascus blade, which just didn't seem to want to harden in oil, and the other was my very first ever knife, forged out of an old mystery metal file, but that blade was so thick there was no way it was ever going to crack =D.
 
Looks sweet, quickly edit the post telling us all you used that hightech doohickey to distress the blade and sell it for a mint.

I was hoping to hear a loud pop when it went in, maybe we should try it again without the clay.:eek:
 
That's why I use oil here. I been telling people that for years. I played in that movie before. Sorry that happen. But I believe you will over come that in time. :thumbup::D:jerkit:
 
Conserve water...... It should only be used to drink, and wash your fanny.

Usually not good for blades (as you found out). I've been there and done that, and got a pile of cracked steel to show for it. A water quench can give you an instant "serrated" blade (whether you want it or not).

Ya gotta watch that "IG"........ He still thinks its normal for a HD motorcycle to shake the fillings out of your teeth at a redlight.:eek:

Robert-the-oil-man......:D
 
Sorry about that blade Larry, looks like it would have been a real keeper!! Are you sure that it was the water?? IG didn't breath on it when you weren't looking did he?? :barf: :D
 
toecutter said:
Looks sweet, quickly edit the post telling us all you used that hightech doohickey to distress the blade and sell it for a mint.

I was hoping to hear a loud pop when it went in, maybe we should try it again without the clay.:eek:
Click to expand...

Nathan, see what happens when someone doesn't listen.:jerkit::eek:;)
I just realized that I have a BBBB Beaver and BBBB Butthead (Nathan) hanging around my shop. HEHEHEHEHEHE!!!!
 
rocketmann, from your avatar I know where you have been;) Not in the picture but behind you and to your side is a large propane pig, then an old overgrown and twisted black locust or some kind of bean bearing tree with some wisteria growing on it (many a smith has enjoyed the shade from that tree) beyond that is a large gray building that smells like Satan is passing gas inside. I have taken more pictures around that anvil than perhaps any other spot;)

Sorry about the blade T Blade, in my shop water is for drinking, or rinsing the quenchant I do use off the blade. They quit making steel what was REALY matched for water quenching a long, long time ago, and I even have some images of micro-cracking from water quenches in that stuff. Even 10XX has manganese in it which makes fast oils preferable in thin sections, but many folks claim huge success in quenching richer alloys in water all the time, the problem is that if they really looked into why that shouldn't work they would realize what they are doing to make it possible. When a steel is alloyed to through harden in oil, its very nature is designed to avoid an intense quench and still harden fine, so it is predisposed to serious hardness. Most folks play with the soak times and temps in order to be able to quench these in water, but what is happening is that they are working to defeat the factors that will cause the steel to harden deeply in order to keep it from self destructing. Handicapping the steel in order to force a quench medium on it that it was not intended for. You will notice that the water quenching sword guys really love hypoeutectoid steels even in 10XX, this is because it allows them to undersoak and leave the ferrite depleted of carbon and less prone to over hardening despite the manganese present. Steels with more than .8% carbon are not as forgiving and will not allow them to handicap them as much in the soak.

Now that I have done my share of work with bloomery steel I realize that we really have come a long way with our steel making and treating technologies, we can tap almost every bit of a steels potential these days. The compromises we must make are much smaller than in past times. Trying to step backwards and use ancient techniques with modern steels can be about as fruitful as trying to work on a PC with the tools and knowledge meant for an abacus.
 
toecutter said:
Looks sweet, quickly edit the post telling us all you used that hightech doohickey to distress the blade and sell it for a mint.

I was hoping to hear a loud pop when it went in, maybe we should try it again without the clay.:eek:
Click to expand...


Next time you do the forging and we'll use the water quench :D, I already had my turn at it :eek:
 
Actually, I really didn’t mind having the blade crack :jerkit: that was a first (and I hope last) time that’s happened to me.

I thought it would be cool to do the fluorescent mag particle test so I could take a pic and put it up on the web.

I perform non-destructive testing for a living so the MT wasn’t a big deal, I had one of my minions :eek: perform the test.

Basically I put an electro magnet on the piece, if their are any discontinuities (cracks) they will become magnets, while the electro magnet is energized I spray a liquid containing iron power colored with fluorescent dye onto the test piece, which is attracted to the magnetic cracks, shine a black light on it and voila, you get to see those discontinuities :D.
 
T Blade, it certainly shows up problems !! We used to show that to customers who wouldn't believe they had problems !! You can even play with colored filters to make it more dramatic.
 
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