Accession Number : AD0710107

Title :   TEMPERED MARTENSITE BRITTLENESS IN EXTRA-LOW-CARBON STEELS,

Corporate Author : LAVAL UNIV QUEBEC

Personal Author(s) : Delisle,G. ; Galibois,A.

Report Date : 24 JUN 1968

Pagination or Media Count : 10

Abstract : A certain number of observations in extra-low-carbon steels were made and summarized. (1) It was shown that low-carbon martensitic steels offer a unique combination of enhanced strength and ductility. (2) It was established that extra-low-carbon steels appear to have a better combination of strength and ductility in the as-quenched condition than after tempering at low temperatures. (3) It was ascertained that a loss in ductility occurs in the vicinity of 300-400C. This indicates that tempered martensite brittleness also exists in extra-low-carbon steels. (4) The tempered martensite brittleness is thought to be linked with the alignment of the platelets cementite along boundaries and subboundaries causing a marked reduction in the mobility of the remaining dislocations. The embrittlement disappears with the loss of the alignment of the platelets which seem to change to spheroidal particles. (5) It was shown that an addition of 0.055% Al does not prevent the occurrence of tempered martensite brittleness, whereas an addition of 5% Ni decreases it slightly. (Author)

Descriptors :   (*STEEL, BRITTLENESS), MARTENSITE, TEMPERING, CANADA

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE