Hybrid kris for comment

[Ian]

There is frequent mention of homogenous steel in the comments above. The adjective homogenous requires some thought, being a relatively recent alternative to homogeneous, which indicates uniformity of composition or structure.

There is a concise discussion of homogeneous versus homogenous in the Gammarist web site:

Homogeneous means (1) of the same or similar nature, and (2) uniform in structure or composition. Its corresponding noun is homogeneity.

Homogenous, whose corresponding noun is homogeny, is a little-used biological term whose old sense has mostly been lost. Today, it’s primarily a variant of homogeneous in general usage, though it still has uses in science, where spelling it any other way would be considered an error.

Though some careful nonscientific writers continue to try to keep the words separate, it is a lost cause in popular usage. And the change is not new; people have been using homogenous in place of homogeneous throughout the English-speaking world for at least a century, ... so trying to preserve the distinction is probably a losing battle.

https://grammarist.com/usage/homogenous-homogeneous/

Using this now accepted meaning of homogenous, then homogenous steel would be steel that is produced with a uniform chemical composition and microscopic structure.

If we take this homogenous steel and then fold it on itself several times by heating and forging, do we still have homogenous steel? I would argue that the faces of the various layers when heated and exposed to air would have different chemical and structural characteristics from the subsurface steel, thus introducing heterogeneities (at least at the microscopic level) to the various layers of steel.

I think the only way to preserve the homogeneity of the original steel would be to forge a blade without laminations. Even then, the homogeneity would again be lost through any differential heat treatment/quenching.

Using various steels of different composition to start with, and then forging them into each other, obviously introduces much greater heterogeneity to the final product than starting with a homogeneous stock.

[JBG163]

Homogeneous steel in my opinion, have an uniform structure and composition. So it can correspond to only modern steel, or steel coming from High furnace (cast iron that is heated to lose carbon and make steel).

Japanese sword of extremely good quality, are almost considered homogeneous steel. The bloomed steel, heterogeneous at the origin, is so much folded that it's almost homogeneous.

But, all the blades coming from bloomed steel are forge folded, and considered heterogeneous in composition.