Morphology and Crystallography of Sub-Blocks in Ultra-Low Carbon Lath Martensite Steel

The morphology and crystallography of sub-blocks in lath martensite were studied in all interstitial free steel. In each block the sub-blocks are classified into dominant and minor sub-blocks in terms of the volume fraction. The orientation relationship between the dominant and minor sub-blocks is [011]alpha'/10.5 degrees. Minor sub-blocks have a plate-like morphology and are connected to each other with the habit plane close to {111}gamma, and their growth directions close to < 10 (1) over bar >gamma. [doi: 10.2320/matertrans.MRA2008409]