CEMENTITE PRECIPITATION DURING TEMPERING OF MARTENSITE UNDER THE INFLUENCE OF AN EXTERNALLY APPLIED STRESS

J. W. Stewart, R. C. Thomson and H. K. D. H. Bhadeshia

Abstract

The precipitation of cementite under the influence of an externally applied stress, during the tempering of martensite in steels, is investigated using transmission electron microscopy. The stress appears to favour the development of particular crystallographic variants of cementite in any given plate of martensite. Hence, a Widmanstatten array of cementite particles in a normally tempered sample changes to an array consisting of just one variant in stress-tempered samples. The results are discussed in the context of the mechanism of carbide precipitation during the lower bainite reaction.

JOURNAL OF MATERIALS SCIENCE, 1994, Vol.29, No.23, pp.6079-6084

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