2001 年 41 巻 12 号 p. 1502-1509
In this research, the carbides of as-cast AISI M7 high-speed steel, in which different amounts of V and W were replaced by equivalent Ti and Nb, were investigated using light and electron microscope. EDX and WDX analysers were used in order to recognize the type and formulae of carbides. The volume fractions of each type of carbides are determined using especial etchant, so that the effects of Nb and Ti on the carbides types, shapes and volume percentages could be understand.
The results show that Nb and Ti increase the volume fraction of MC instead of M2C or M6C and decrease the volume fractions of total carbides. It is also found that, the volume fractions of M2C decrease and M6C increase with increasing Nb percentage.