Theoretical considerations for substitutions in alloy steels

Abstract

THE development of materials possessing certain specific properties was followed on empirical basis in the past. This was specially true in alloy steels, where there are plenty of complications and variables, each effecting the properties sought in its own way. As the theoretical background of this behaviour was least understood, development of materials in the nine-teenth and early twentieth century was based on very laborious approach which was time consuming on the first hand and costly on the other hand. Quite lately attempts have been made to rationalise the metal science on more scientific basis, and although the dream of the designing alloys by slide rule, posse-ssing the required properties, is still far from being achieved, the production costs and wastage in time can be avoided to a considerable extent by it proper application of the factors which have been understood lately. It is the object of this paper to describe these factors in detail so that the attempts in future will he based on more realistic and scientific lines than hitherto followed.