METHOD OF QUANTITATIVE-ANALYSIS FOR FAILURE SURFACES IN THE TRANSMISSION ELECTRON-MICROSCOPE

An effective and reliable method is proposed for the quantitative analysis of failure surfaces in metals. The method is based on the estimation of shearing on sulfide inclusions in fractures of impact test specimens by transmission electron microscopy. The authors examined fractures in failed specimens from the axial zone of a casting of low-carbon steel before and after boron microalloying. The quantitative analysis of the surface indicated that the increases in strength and plasticity on boron microalloying are associated with a reduction in the proportion of failure due to shearing and also in the number of microdiscontinuities and quaternary inclusions of film morphology.