Mn-Depleted Zone Formation in Rapidly Cooled High-Strength Low-Alloy Steel Welds

Abstract

The mechanism of formation of an Mn-depleted zone (MDZ) near the inclusion in a steel weld was elucidated based on quantification of MDZ depth and thermodynamic calculations. The effective inclusion phase for intragranular nucleation, which increased as a function of increasing chemical driving force, satisfied the requirements for presence of a considerable quantity of Mn in the phase, and a lower precipitation temperature compared with the solidus temperature of the matrix.