THE APPLICATION OF METALLOGRAPHIC TECHNIQUES TO THE STUDY OF THE TEMPERING OF HSLA-100 STEEL

A study of a quenched, and a quenched and tempered low-carbon, copper- containing steel (HSLA 100) was conducted. The primary investigative t echnique employed was transmission electron microscopy. Quenching the steel from the austenitizing temperature yielded a microstructure that was predominantly lath martensite. However, a significant amount of r etained austenite was also present. Niobium carbide particles were als o documented in the as-quenched structures. Tempering at 605-degrees-C for 1-3 h yielded a heterogeneous distribution of epsilon-Cu, much of which was associated with the lath boundaries. The austenite was high ly resistant to decomposition during tempering at 605-degrees-C and, a s a consequence, little evidence of cementite precipitation was found.