Critical Failure Strain of Oxide Scale in Boiler Austenitic Tubes
Keywords:austenitic alloy, oxide scale growth, critical failure strain, heat transfer, boiler tubes
Exfoliation of oxide scales is known to be associated with the stress and strain developed during the oxide growth. This paper presents a simple procedure to estimate the oxide scale growths and critical failure strains in boiler austenitic tubes over a period of time. In this work, a classical heat flow formula and the relationship between the Larson Miller Parameter (LMP) and the scale thickness were utilized. An approach called Advance Oxide Scale Failure Diagram (A-OSFD) was adopted. The oxide scale failure diagram would provide a general guidance to the power plant engineers to estimate the critical strains.The technique may be used as a supplementary condition monitoring tool for oxide scale growths and to evaluate the critical failure strains.