Taking TP347 Hand Super304H(shot peening)used in four 600 MW ultra-supercritical units in a plant as the example

H2 productions in the steam under conditions with different unit loads and oxygen addition amounts was analyzed.The feedwater oxygenated treatment has no direct effect on growth of the oxide scale based on the analysis of the correlation between H2 production amount and growth rate of oxide scale.The thickness of oxide scale

metallography and elemental composition were also investigated for the superheater tubes.The results indicate that

adding oxygen in the feed water has no direct effect on growth of oxide scale.At the design wall temperature

the unit load has little effect on the growth of oxide scale

while the material type has greater influence.The oxidation resistance of TP347 His inferior to that of Super304H(shot peening).