Source : Webster's Revised Unabridged Dictionary (1913)

Manganese steel \Man`ga*nese" steel\
   Cast steel containing a considerable percentage of manganese,
   which makes it very hard and tough. See {Alloy steel}, above.

Source : WordNet®

manganese steel
     n : a steel with a relatively large component (10-14%) of
         manganese; highly resistant to wear and shock [syn: {austenitic
         manganese steel}]