Morphology and Stability of the Widmanstaetten Structure.

The paper deals with the space arrangement of the W-ferritic plates, their structure, and the influence of heat treatment on the morphology in hypoeutoctoid steel with 0. 33% C. Experimental results show that in space arrangement, W-ferritic plates create several colonies each austenitic grain. These plates have a semidisk shape and contain elongated grains and subgrains. By increasing the austenizing temperature at a relatively constant cooling rate, the width of ferritic plates and the distance between them increases. Tempering of the W-ferritic-pearlitic structure at 680 degree C for 4 hrs leads to spheroidization of pseudopearlite, but the plate-shaped morphology and elongation of the ferritic grains and subgrains remain preserved. The W-structure manifests in case of repeated austenization and a slow cooling rate a considerable stability.