- 鐵と鋼 : 日本鐡鋼協會々誌 (ISSN:00211575)
- vol.56, no.2, pp.266-276, 1970-02-01
It is reported in this paper that the combined addition of 0.03% Nb and 0.55% Mo in quenched and tempered steel has shown such a high strength increase that can not be deduced from the present knowledges. It is also investigated whether there is any other combination effects between elements of VIa or Va family and elements of VIa family in the periodic table, as in the case of Nb and Mo. 1. It is found that Nb-Mo added steels have the largest combination effect, Ti-Mo, Zr-Mo and Nb-Cr steels have a slight effects, and Ti-Cr, Zr-Cr, Nb-W steels have none of the combination effect. 2. The reason why such combination effect occurs has been investigated. It is found that, in the case of combination having such effective combination effect, a large number of, and a great amount of cubic duplex carbide particles of IVa or Va element containing VIa element in it precipitate in the course of tempering, and it is infered that such duplex carbides result in the great combination effect of the steel. 3. The extraction method of Nb or V precipitates from steels is investigated, and it is found that the best is the (1+1) HCl aq. extraction method.