AbstractsChemistry

"The vast amount of attention that has been given to the development of high-temperature service alloys since about 1940 has resulted in the production of numerous compositions for many elevated temperature applications. Particularly in the aircraft industry, with the jet engine, and the power industry, with the gas turbine, have these applications been most demanding. War research has developed a large number of high-temperature service alloys, many of which are in use today, and the alloy ingredients vary widely...it may be readily be seen that there is no one alloy, or one system of alloys which has been developed that has satisfied any extensive portion of the user's needs. However, all of these compositions have Co, Cr, and Ni in some proportions, plus various other alloy additions. An investigation by Dr. R. S. Dean, who considered various alloy compositions for high temperature service, has shown that the more basic requirements of such high-temperature alloys are met in the Co-Cr system of about 60% Co-40% Cr. This system having the distinct inherent disadvantage of poor cold-working properties, Dr. Dean found it advantageous to add 25% manganese, thereby producing a ductile alloy. There being no investigations supplementing the work by Dr. Dean, the following investigation was undertaken to further determine the properties of the Co-Cr-Mn alloy by observing: The changes in hardness with heat-treatment; the microstructures of the cast, worked, and heat-treated alloy; the thermal expansion from room temperature to maximum service temperature; the oxidation resistance at service temperatures; and the cold ductility by swaging" – Introduction, p. 1, 3.