00000nam 2200000za 4500 9.840489 CaOODSP 20221107151845 cr ||||||||||| 170727s1968 oncad ob f000 0 eng d CaOODSP eng eng fre ger n-cn--- M38-8/61E-PDF M38-8/61 Smith, E. An investigation of secondary hardening of a 1% vanadium - 0.2% carbon steel [electronic resource] / E. Smith, Physical Metallurgy Division. Ottawa : Queen's Printer, 1968. p. 583-593 : charts, ill. Reprint series ; RS 61 Cover title. "Reprinted from the Acta Metallurgica, Vol. 14, 1966." Historical publication digitized from print 2017 [by Natural Resources Canada]. Includes bibliographical references. "Steel samples were quenched into oil, tempered and examined by transmission electron microscopy. The structure of the quenched steel was very similar to that of plain carbon steels of similar carbon content. Most of the ferrite grains were needles or large untwinned plates. Within the grains was a very high density of dislocations and also a Widmanstätten precipitate of iron carbide, formed during the quench. This structure was resistant to tempering up to about 20 hr at 500°C when the secondary hardening reaction appeared to begin. Peak hardness coincided with the formation of coherent platelets of vanadium carbide only a few unit cells in thickness and about 100 A in diameter. The dislocation network was stable under these conditions and appeared to be hold by the precipitates. The fall from peak hardness was accompanied by increase in size and reduction in number of the vanadium carbide particles. At the same time the dislocation network cleared from the grains accompanied by polygonization and recrystallization of the ferrite. Attempts were made to correlate measurements of strength and particle density with various theories for precipitation hardening. Moderato agreement was found with theories dependent on particle strength and spacing, but not for hardening based on coherency strains"--p. 583. Includes abstracts in French and in German. gccst Metals gccst Physics Canada. Natural Resources Canada. Canada. Department of Energy, Mines and Resources. Canada. Mines Branch. Reprint series - Dept. of Energy, Mines and Resources, Mines Branch ; RS 61 (CaOODSP)9.834843 PDF 13.64 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M38-8/M38-8-61-eng.pdf 300140