Inclusion formation in low-alloy steel welds

摘要

This paper summarizes four models for describing inclusion formation in steel welds. These methods include simple fixed oxidation sequence model, thermodynamic model, thermodynamic-kinetic model, and thermodynamic-kinetic- fluid flow model. Complexities of these models increase with a need to describe details of the inclusion formation. The applicability of the models was illustrated with two examples. In one of the examples, thermodynamic calculations of phase stability between liquid steel, AlN and Al(sub 2)O(sub 3) explained the inclusion formation in self-shielded flux cored arc weld. In the second example, thermodynamic-kinetic calculations illustrated the competing effects of weld metal composition and cooling rate effects on the inclusion formation in electron beam and laser beam welds. Limitations of the current inclusion models and recommendations for future work on the inclusion formation were highlighted.