BAINITE NUCLEATION FROM MINERAL SURFACES

Experiments have been conducted to study the nucleation of bainite at interfaces between ceramic compounds and low-alloy steels. To facilita te this, chemically pure mineral powders were pressure bonded to steel samples. The resulting composite samples were then heat treated to in duce transformation, and hence compare the transformation behaviour in the vicinity of the ceramic/steel interface to that within the bulk o f the steel. It is found that the minerals may be categorised into thr ee groups, according to their observed efficacy in inducing the nuclea tion of bainite.The dominant reason for the stimulation of bainite nuc leation seems to be a chemical interaction between the mineral and the steel. One noteable exception is TiO, which, within the limits of res olution, appears to remain inert, and yet enhances bainite formation.