So you have many certified reference standards for your spectometer that fall in this range of chemistry?
What kind of engine was this in?
How old? Made where?
You also have to be careful doing chemistries because many valves are plated or coated.
There have been dozens of proprietary alloys used over the years.
The problem with your chemistry is that the C is too high, and the Mn and/or Ni too low for the alloy to be austenitic.
At the same time the Mn is too high for a ferritic stainless.
8440: Medium to heavy duty steel alloy with a higher chromium content to enhance high temperature strength.
Sil 1: Heavy duty steel alloy with an 8.5% chromium content for excellent high temperature performance. Used for many factory high performance intake valves.
Sil XB: A ferritic stainless steel alloy, with 20% chromium content and 1.3% nickel. Used in heavy duty intake valves.
422: A stainless steel alloy specified for high performance intake valve usage. This specialty type of stainless is designed with the temperature ranges and characteristics of intake valves usage in mind, and is different from the more common exhaust valve stainless materials.
21-2N: Austenitic stainless steel with 21% chromium and 2% NICKEL. As the most popular exhaust valve material, it has excellent performance characteristics at elevated temperatures. With additional heat treating and manufacturing processes, this material can be upgraded to become the ultimate choice for exhaust usage. With different processes, it makes for a good quality, inexpensive intake valve as well.
21-4N: An Austenitic stainless steel similar to 21-2N, except for a greater nickel content (4%), used as an alternate to 21-2N.
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Plymouth Tube