barnett25, forgive me for butting in but I thought I would help watch your back for a moment. You are correct in what you are saying, but the way it can be read prompts me to help out a little in clarifying what you were saying before you draw the fire of many who are passionate about some of these topics.
Damascus (and now I risk drawing fire, but I am building the case for just calling any of it “damascus steel” since many of the reasons not to are based on dubious information), is not really better or worse than singular high carbon or tool steel, it is just “different”.
Thank you for pointing out the carbon thing, as it is very much true that the carbon will diffuse and equalize very quickly under normal circumstances of folding and welding. The alloying characteristics of the individual steel layers will however remain. Carbon atoms are very small compared to iron and thus can skitter between them very quickly while say chromium or nickel atoms are very much larger and cannot move between the iron atoms like carbon. Because fo this one can build up alternating layers of different abrasion resistance, not necessarily hardness based upon carbon content. Thus while for the most part pattern welding is really for looks, one must also admit that it is “different” from mono-steel. I like to say that damascus doesn’t stay sharper longer than normal steel, but it does go dull in a different way. Due to differences in abrasion resistance damascus tends to get ragged or toothier, like a saw, as it wears at the edge, thus it will continue to tear through soft fibrous targets aggressively while a steel that wore more smoothly will not, therefore it has the appearance of holding a better edge but is just wearing differently for specific targets. This ragged toothy effect is not so great in push cuts and would be rather distressing on a razor if not kept polished.
Ancient crucible steels behaved in much the same way but relied upon heavy carbide networks, not necessarily alloy banding, but carbide banding surrounded by a soft iron matrix. This allowed blades made from it to cut soft targets really well and stay keen due to the really hard carbides while still being ductile to some degree due to the bulk of soft iron. Ric Furrer likes to say “imagine diamonds in pudding” but I like to give the soft parts a little more strength and call it “diamonds on Play-do”. This is not to say that alloying didn’t play a role in the carbide segregation, and the principles of how the networks got there in the ingot cooling phase are the same but if one doesn’t take time to identify the differences between wootz and modern steel with nasty banding, well issues can arise
I also do not think that either material would stand much a chance in strength tests against modern tool steels, but in other tests involving cutting or some ductile behavior while perhaps not better once again both may be “different”.
Tuesday, your question on the “best” combination will get you just this side of 1,000 different answers with none being correct while at the same time none being wrong either. However you did give us a key to zeroing in on some better answers with your use of the word “strongest”. In terms of strength the best combination would involve two steels of higher carbon content with heat treating requirements that are almost identical, this would allow you to get a more homogenous hardness range resulting in a steel that would have the most resistance to deformation in strength tests such as tensile for example.
