抄録
Boriding of iron with B4C was investigated for getting an extremely hard surface(Hv≅2, 000). Carbonates of alkali metals were used for accelerators for bonding. The results obtained were summarized as follows: (1) The most suitable composition of the bonding agent was 80wt% B4C-20wt% Na2CO3. (2) The bonded layer was composed of Fe2B, the hardness of which was 1, 400-1, 900kg/mm2. (3) The bonding rate did not depend on the crystal grain size of iron. (4) The relation between the specific rate of bonding and the activation energy was derived, by which the value of activation energy was determined to be 25kcal/mol. (5) The mechanism of bonding of iron by treating with B4C-Na2CO3 system was analyzed, and successive reactions including B2O3 and Na2B4O7 were discussed.
