Abstract
THE maximum cutting hardness of pure carbon tool steel is achieved by water-quenching. With the introduction of Mushet's special steel, engineers obtained a material which was called “self-hardening,” because it did not require to be water-quenched in order to bring out its maximum cutting hardness. It was sufficient for the tool to be cooled from above a certain critical temperature in air. The modern highs-peed tool steel falls into the same class of materials, the chief difference from Mushet's special steel being that the “lip” or “nose” of the tool requires to be actually melted and then cooled in an air blast if the maximum cutting hardness is to be obtained. Stated in general terms, therefore, the rapid-cutting tool of to-day is gas-quenched as contrasted with the carbon tool, which is water-quenched.
Article PDF
Rights and permissions
About this article
Cite this article
CARPENTER, H. Hardness and Critical Cooling Velocities of Steels . Nature 97, 452 (1916). https://doi.org/10.1038/097452b0
Issue Date:
DOI: https://doi.org/10.1038/097452b0