Investigation on Oxidation Behavior of Super304H and HR3C Steel in High Temperature Steam from a 1000 MW Ultra-Supercritical Coal-Fired Boiler

Jingjing Li,Haidong Ma,Min Xue,Yungang Wang,Qinxin Zhao

doi:10.3390/en12030521

Jingjing Li, Haidong Ma + Show 3 more

Open Access

https://doi.org/10.3390/en12030521

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Abstract

Oxidation behavior of Super304H and HR3C steel in high temperature steam from an ultra-supercritical coal-fired boiler was investigated in this paper. The results showed that the steam oxidized surface of Super304H ware composed of Fe2O3, Cr2O3 and FeCr2O4, the oxide scale had a thickness of 50–70 μm. In addition, the steam oxidized surface of HR3C ware composed of Fe2O3, the oxide scale was about 20μm in thickness and contained few pitting. The oxidation product layer of the two samples could be divided into two layers, including outer layer enriched O element and Fe element, and inner layer enriched O element and Cr element. Furthermore, oxide scale spalling was observed on the surface of Super304H sample.

Highlights

Increasing steam parameters of utility boilers can effectively improve fossil energy utilization to reduce pollutant emissions [1,2]
It can be seen that the steam oxidised surface of the Super304H were mainly consist of Fe2 O3, Cr2 O3, and FeCr2 O4 In contrast, the steam oxidised surface of the HR3C sample was only Fe2 O3
The oxidation surface morphology of the sample and the elemental composition of marked region were shown in Figures 4 and 5, respectively

Summary

Introduction

Increasing steam parameters (pressure and temperature) of utility boilers can effectively improve fossil energy utilization to reduce pollutant emissions [1,2]. The application of ultra-supercritical technology puts higher requirements on the steam oxidation resistance of high temperature heating surface materials [3,4]. There are few materials used in boiler with good high temperature oxidation resistance, steam oxidation resistance and mechanical property in the temperature range of. As main steam temperature in the ultra-supercritical boiler develops continuously to high parameter rapidly, metal wall temperature of super-heater and re-heater gradually approach or exceed 680 ◦ C, which is in the second peak area of high temperature oxidation rate, the oxidation rate will increase greatly. Super304H has good endurance strength and high temperature steam oxidation resistance, HR3C has better heat intensity property. Super304H and HR3C have been widely used in the manufacture of superheater or reheater [10,11]

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Discussion

Conclusion