GROSSMANNの焼入性予測式の実験的検討

抄録

According to GROSSMANN'S equation, the effect of alloying element on the hardenability of a steel is expressed in terms of the multiplying factor. Its reliability, however, becomes doubtful since it was confirmed that B-factor is not a function of only B-content. Therefore, in order to confirm whether GROSSMANN'S equation is reliable or not, the relation between a multiplying factor of different alloy element and its content has been investigated. The results obtained are as follow:
1) The multiplying factor f_X is a function of D_S as well as content of alloying element X. D_S is the hardenability of the steel before addition of alloying element. X. With increasing D_S, f_X becomes smaller.
2) Boron factor, f_B, is a function of D_I° and shown as follows,
f_B=1+1.6/D_I°, where D_I° is the hardenability expressed by ideal critical diameter of B-free steel.
3) Accordingly, GROSSMANN'S equation is not always realized. When D_S is smaller than 2 inch and the hardenability of the steel after alloying element added is less than 33.5 inch, GROSSMANN'S equation is available. 4) There is more intimite relation between the critical cooling velocity and alloy content, X than between D_I and X. D_I is ideal critical diameter of a steel.