Excerpt from American Society for Testing Materials, Affiliated With the International Association for Testing Materials, Vol. 17: Proceeding of the Twentieth Annual Meeting, Held at Atlantic City, New Jersey, June 26-29, 1917 Most Of the alloying elements, and notably carbon, man ganese, and nickel, retard this transformation greatly. Thus 2 per cent of manganese plus 2 per cent of carbon retard it so that in the water quenching Of thin pieces the austenite state is preserved. With 5 to 7 per cent of manganese it is SO slow that even in air cooling it goes only as far as the intermediate martensitic state. Hence the brittleness of these steels of intermediate manganese content. With say 12 per cent of manganese the transformation is so sluggish that the austenitic state is preserved even through a common slow cooling. The water-quenching of manganese steel in current manufacture is not to prevent the loss of the austenitic state, but to suppress the precipitation Of the iron-manganese carbide, cementite, which would occur during slow cooling. The broad plates of this cementite would embrittle the mass by forming partings of low cohesion. It is derived from the large carbon content of the ferro-manganese used, the cheapest source Of manganese. Carbon-free manganese steel should not need quenching. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.