Design, development, structure and properties of some new stainless steels for high-temperature use

The early-historical development of the 18/8 and other high-Ni-Cr stainless steels by Brearley and others is well known. However, it is now well established that the use of niobium additions to promote solid solution strengthening in Fe-, Ni-, and Co-base alloys was based on the early work of Fleming and others of this field. The work of Betteridge on the Nimonic alloys indicated that alloying elements entering into solid solution with nickel should have much higher melting points than nickel (i.e. Ni = 14550C, Nb = 24680C, and W = 34000C) as in the case of the refractory metals Ta, W, Mo, and Nb, all of which have melting points above 20000C. In the present work a series of new stainless steels has been designed based on the previous theoretical work using high-purity fine powders to which were added appropriate amounts of niobium. (author)