Forging vs stock removal strengh

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Jessetheknifeguy

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I'm not going to ask which I'd better or anything like that, but I've heard people say that a knife with the same materials, ht and geometry will be tougher if it's forged because of the grain or something. Does steel really even have a grain? What is your experience? Has anyone done any testing? Just wondering.
Thanks
 
Jessetheknifeguy said:
I'm not going to ask which I'd better or anything like that, but I've heard people say that a knife with the same materials, ht and geometry will be tougher if it's forged because of the grain or something. Does steel really even have a grain? What is your experience? Has anyone done any testing? Just wondering.
Thanks
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All steel I’d forged from the mill.

Forging saves materials. That’s it. Unless you are doing pattern welding, then forging is necessary.

Forging can ruin steel. Forging too hot, or too cold can damage the steel beyond repair.

You can normalize then thermal cycle most steels. It’s absolutely necessary for forged steels, and for some stock removal steels depending on the condition from the mill.

If the steel is undamaged, and in the same condition prior to heat treating, there will be no difference in performance between forged or stock removal blades.
 
Forging is fun … that's the largest part of its popularity.
Forging allows things like integral bolsters to be made without grinding/milling away 3/4 of a bar of steel.
Forging allows some shapes that would be difficult or wasteful made from bar stock.

Pretty much every forged knife will still need some amount of stock removal.

Properly made, the end result ( in a knife) is the same as far as hardness and strength.


Forging adds strength only on bent shapes where the continuous grain direction follows the angle. Think of a shelf bracket that is forged vs one that is cut from sheet stock. The forged bracket will bear more weight.
 
I see pattern welded blades with the grain running all different directions. I always thought that the grain had to run length ways like the blade to be stronger, but I see blades with the pattern running all different directions on some makers blades. Which way or does it matter which way the grain or pattern runs to make it the strongest blade possible in a pattern welded blade.
 
Jessetheknifeguy said:
Does steel really even have a grain?
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Yes, steel has directional ’grain’.
But so much emotional hocuspocus BS from knife worshipers, you justified to be suspect of knife specific online info.

But regarding industrial forgings, you can find loads of true info without the burden of emotional folklore online or YouTubes covering the grain subject and how it applies to steel.
 
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A material's 'texture' refers to a preferred orientation in the crystal structure, if it has one. This isn't the same thing as a preferred orientation of the grain boundaries, which is what you'd see with optical microscopy, although they are often interrelated. Both can contribute to the material's properties. Both also tend to reduce or disappear during a phase change, such as for the austenite in a ht. I don't know how much or if at all the texture of any carbides/cementite/etc. would have on anisotropy (preferred orientation in a property) in the rest of the material after a phase change though. The texture in the carbides/etc. that don't undergo a pt themselves would, but I don't know if it would be noticeable.
 
Texture is one part of anisotropy. It isn’t the primary controlling factor when it comes to directional differences in tool steels.
 
In a plate there will be big differences between rolling direction and transverse direction due to segregation band structure, so closed (or open) die forged tools will be tougher, on theory. Having said that, steel is forged in the mill, so if one buy a piece cut parallel to the rolling direction of the “grain”, the knife will be tougher than if you buy a piece of steel of unknown rolling orientation.
 
Here is an interesting tidbit. When we order some marine shafting for repairs, at times the agencies require it to be forged. If its not stronger, why?
 
Strength = hardness in most cases. Tensile strength, yield strength, etc. Sometimes we use strength and toughness interchangeably but they are two different things.

Hoss
 
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