The Investigation of Microhardness of Grey Cast Iron Dendritic Structure

摘要

The dependence of the dendritic crystals of primary austenite microhardness on indentation load within the range from 0,01 to 2 N is investigated. Tests are carried out on specimens with a volume fraction of a dendritic component of 15%, 30% and 60%. It is found that at any volume of dendritic fraction microhardness increases with an increase in load from 0,01 to 0,1 N and then, in the process of a further indentation load growth, decreases a little. Decrease in microhardness in the range of loadings from 0,1 N to 2 N can be accounted for by growth of an impression size and a spread of plastically deformed volume to a dendritic crystal surface.