Structural state of armco iron in the zone of pulsed laser irradiation

Optical microscopy, transmission electron microscopy, X-ray diffraction, and microhardness measurements were used to study the structure formation in armco iron in the zone of pulsed laser irradiation. In this zone, there arises either an increased density of dislocations that form a fragmented structure in the initial grains (at a density of laser irradiation energy below 3 J/mm2) or a set of different microstructures (at an energy density of 12-14 J/mm2). The variety of microstructures is determined by the specific features of the Fe-C phase diagram and structure formation at high heating rates and high rates of cooling from different temperatures. A correlation between strain hardening and dislocation density in the zone of laser action was established.