No it's not. Where did you come up with this statement?
There may be sulfur in the chemical composition true, but it's called High Speed for a good reason. And why it became so expensive to produce knife blades from, and why Benchmade stopped using it. The material makes for an awesome cutting tool but is difficult to sharpen due to it's hardness.
From the internet after 2 minutes of searching:
"Tool steels such as high speed steel are alloys containing many elements other than iron, each of which influences its chemical properties. These elements are carbon (0.65 to 0.80 percent), chromium (3.75 to 4.00 percent), tungsten (17.25 to 18.75 percent), vanadium (0.90 to 1.30 percent), and in very small proportions cobalt, molybdenum and aluminum. Other elements that may be present in small quantities are manganese (0.10 to 0.40 percent), silicon (0.20 to 0.40 percent), nickel (about 0.30 percent), copper (0.25percent), phosphorus (about 0.30percent) and sulfur (about 0.30percent).
Broadly, high speed steels are classified into two categories according to its chemical composition: T type (tungsten based) and M type (molybdenum based.)"
M2 is what Benchmade chose.