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Post by LastGodslayer on May 20, 2014 13:48:51 GMT
So, to keep it simple (assume a blade shaped correctly, heat treated to the best compromise you can think of for a given steel):
In theory a (well) forged blade will be stronger than a blade (well) made through stock removal, because the grain is conformed in the shape with very little end grain. Right...?
So, what if I'm talking a PM steel? Or some very fine grain 52100? Will forging give an extra increase in performance (assuming grain size is kept under control and nothing percipitates)?
In real world performance does it make a difference? I mean, how far would I have to push the geometry to see the difference?
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Post by L Driggers (fallen) on May 20, 2014 14:27:40 GMT
Doesn't make any different a stock removeable blade is as strong as a forged blade. The heat treat is want controls grain size. Some people will say forging will cause the grain to be all layed out in one direction. I don't believe this and I do both.
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Post by LastGodslayer on May 20, 2014 14:38:10 GMT
Thanks Fallen. So basically, in your experience, no difference? The thing is it is well known forging causes defects that warp the grain, making it conform to the shape as it is being forged. It is also well known that milled parts have visible end grain when cut perpendicularity to the axis to steel was rolled through. Grain size isn't a consideration here since this is more related to the thermal cycles the steel undergoes, but my doubt is, sure there might be an advantage to forging, but that implies a whole new level of equipment and skill I do not have. Would I see a big performance difference if I make a blade through stock removal and get it heat treated correctly instead of forging it?
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Post by L Driggers (fallen) on May 20, 2014 15:06:02 GMT
Yes the heat treat is what will make the blade preforum, Forging you will have to worry about internal cracks you can't see. Hit the blade agianst the anvil horn will help you hear these cracks the blade will have a flat sound. Even this doesn't work all the time. Found cracks on forged blades using the belt grinder too polish the blade up. Have had to throw a few away. in forging you will loose some blades along the way. Anyone who said they are so good they don't loose blades are liars. Even Moran lost blades.
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SanMarc
Senior Forumite
Posts: 3,193
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Post by SanMarc on May 20, 2014 17:31:16 GMT
its all in the Heat treat.. even mono steel blades ground out by stock removal will crack if not done right...
With forging you can reshape the metal to what you want.. Stock removal.. the name says it all...
Both way's meet at the Heat treat and Temper....... After that they are the same..... SanMarc.
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Post by L Driggers (fallen) on May 20, 2014 18:14:00 GMT
Maybe you haven't had it happen to you but I've had cracks during the forging which didn't show, until I've did some grinding on them.
Yes with forging you don't loose as much metal, but I can get the shape I want using stock removeable. It helps when you have a metal cutting bandsaw, drill press and a belt grinder with the right attachments.
But it is fun to shape the steel with fire hammer and tongs. Just not when it is going to get as hot as it will be here in OK soon.
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Post by LastGodslayer on May 20, 2014 18:48:13 GMT
Thanks guys. Forging in the summer... Sounds like a recipe to pass out from dehydration :/
While we are at it, what do you guys feel about forging PM steels like CPM3v and the like? Waste of time?
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Post by L Driggers (fallen) on May 20, 2014 19:10:52 GMT
Never have did those, don't know any one else who ever has. If you want to forge better to start with the simple steels. Like 1060 or 1075, 5160 is a little harder to forge.
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Post by LastGodslayer on May 20, 2014 19:18:35 GMT
Actually I have access to very good PM steels, and I was thinking stock removal, but I'm just wondering if I should invest on basic forging. Seems like there may be an edge in being able to forge blades. Still, for now, I'm sticking to cutting and grinding stuff...
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Post by L Driggers (fallen) on May 20, 2014 19:30:51 GMT
Not really but go the way you want too. I do a lot stock removeable than forging, except on the axes and tomahawks.
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SanMarc
Senior Forumite
Posts: 3,193
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Post by SanMarc on May 20, 2014 21:18:38 GMT
If you get cracks during forging your letting the metal get to cold......
When the metal gets to the right temp is acts like plastic.. and you move the metal around.. takes many heats to get what you want....
And like Driggers said use known steels like 10 series.. 5160 is not that hard to forge as is 9160 ya just have to keep it at the right temp while forging....
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Post by brotherbanzai on May 20, 2014 21:19:08 GMT
LastGodslayer, You're talking about two completely different types of "grain" which don't have anything to do with each other. Grain, in it's normal meaning for steel blades, and as L Driggers is correctly using it, is dissolved and regrown during the heat treatment. For this reason, a monosteel forged blade will turn out the same as a monosteel stock removal blade. The steel doesn't care how it got to it's final shape and the grain is the same for each, given proper heat treatment. The other type of grain is like a wood grain. Steel from a mill has this (very slightly) because it is rolled out in a single direction which spreads any impurities or inclusions along that direction. In the picture below, I show a simplified model of this where it might matter for something like a crankshaft. A) shows the parent hunk of steel from the mill with it's as rolled "grain". B) shows that piece after stock removal into a crank. C) shows the same original piece if it had been forged to shape. You can see how if it were made of wood, the stock removal method would leave it very weak and easily fractured at the bend. In this case, having the wood bent (forged) to shape would result in a much stronger piece. Grain, in this sense, is much less of an issue in steel than in wood. Since swords are generally long and fairly straight, it wouldn't ever really be a problem unless the piece for the blade were carelessly sheared against the direction of the "grain" rather than with it, and even then is only a problem if there were some inclusion or other flaw which would then be spread across the blade rather than along it. You can make all kinds of blades without doing any forging, but you will always need to do stock removal, so it never hurts to get more practice. However, forging is, in my opinion, a lot more fun than stock removal. I myself will be forging a pattern welded long sword blade this summer, in the Florida heat. So I can concur that it definitely sucks to forge in the summer. Attachments:
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Post by L Driggers (fallen) on May 20, 2014 21:46:17 GMT
The few I have cracked might have let the steel get to cold, I learned for my mistakes. Really I have no reason to hit a too cold blade. The gas forge I use will get it back up to temp in just a few seconds 20 at the most.
Hpoe you will have a power hammmer to do a pattern welded sword blade or some strikers.
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Post by LastGodslayer on May 20, 2014 22:57:50 GMT
Thanks guys! Especially to you brotherbanzai as I had no idea these weren't the same "grain". Goes to show how much I don't know and I'm reading books on this stuff.
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Post by Lonely Wolf Forge on May 21, 2014 1:11:23 GMT
once you normalize a blade there is no difference between forged and stock removal
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Post by LastGodslayer on May 21, 2014 13:39:52 GMT
Thanks Saito. So, only in blades that won't see a normalizing cycle will the forging have any effect? I can imagine that on medium plain carbon steels this may be possible, but I can imagine the blade will want to warp according to each hammer blow!
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Post by Lukas MG (chenessfan) on May 21, 2014 16:49:08 GMT
If anything, forging has a negative effect... the way the steel comes from the mill is perfect. The difficulty (with forging) is forming it and then getting it back to the way it was before. With stock removal, you don't have to worry about that. Still plenty of other things to go wrong though. And I agree, forging is more fun. BB is right, too. In every forged sword there's a LOT of stock removal.
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Post by L Driggers (fallen) on May 21, 2014 17:37:04 GMT
There is some stock removeable in a forged blade all the bevels, curves, etc are hammer in. If you wire brush the steel not much scale, use light hammer blows to finish up. Then you will just have a little pitting and hammer marks to take out. All steel from the mill comes annealled so you really don't even ahve to normalize it. Me I do it anyways just to make sure, normalize. anneal, harden and temper. Then final sanding and polishing.
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Post by LastGodslayer on May 21, 2014 17:53:57 GMT
Thanks guys. I guess that for now stock removal is more cost efficient for me. But I gotta be honest, forging sounds pretty cool and God know I hate spending days filing things...
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Post by Lukas MG (chenessfan) on May 21, 2014 19:17:37 GMT
To some degree this depends on your exact method but you'd better get used to filing because no matter how you make a blade or fittings, filing and sanding will play a huge role. I don't draw file blades much anymore (a 1" wide flat piece only rides high spots and deepens dents, you really need a long sanding block to get things flat) but edges, tip geometry, fittings and much more I do with a file. Also (and this is a nice side effect), I find file work quite peaceful and relaxing
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