Let me see if I can get this started with what I know, and let someone else fill in the gaps and correct any of my mistakes:

HiTen aka Hi-Tensle, aka Carbon Steel, also known as 1020 or the slightly better 2040, are your heavy tubes found on lower end bikes of the boom. My Schwinn Traveler (80 model built by Panasonic) was built of this. 32lbs from factory.

Next up is your general Cro-Mo steels, often only marked as 4130. Depending on the thickness of the steel and the what it was formed they got different names from different companies.

From there you get into the high end steels that you often hear about, 531's, Columbus SL, SLX, etc.

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Most older Reynolds you'll find is either 531 (some variation on it, or partially built with it), and 501. Later they got lighter steels such as 753 and a few others.

For Columbus you have from top to bottom: SLX, SL, SP for their higher end tubing. Columbus Tenax is a heavier straight gauge set which is often found on mid 80's Schwinns such as my Passage.

Tange had Champion, #1, #2, (or some mixture there of, someone else can clearify that) and also I know of Tange Infinity which was a lower end Cro-Mo set.

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Tubes can either be straight gauge (same wall thickness from end to end), or butted in some combination. Butting simply means that some areas are thicker than others. Typically the middle of the tubes thinner than the ends where they meet the lugs and or welds, brazing, etc. 531 steel came in both straight gauge and a variation of buttings. My Gazelle Champion is built with 531c which is a double butted 531 set.