摘要
为研究超超临界锅炉用新型奥氏体耐热钢Sanicro25在700℃模拟烟气中与煤灰协同作用下的腐蚀行为,探究了SO_2体积分数对材料高温腐蚀的影响。结果表明:在无SO_2的烟气中,Sanicro25钢由于表面形成了保护性氧化膜而具有良好的耐蚀性;在含SO_2的烟气中,Sanicro25钢出现热腐蚀,母材基体中发生了内氧化和内硫化,并且当烟气中SO_2体积分数达到0.50%时,表面腐蚀产物中发现明显的微裂纹,腐蚀产物剥落较多。
To study the corrosion behavior of new austenitic heat-resistant steel Sanicro25 for ultra-supercritical boilers under the combined action of simulated flue gas and coal ash with different SO_2 concentrations at 700 ℃, an analysis was conducted on the effects of SO_2 concentration in flue gas on the corrosion behavior of the material. Results show that Sanicro25 shows good corrosion resistance in simulated flue gas without SO_2, due to the protective oxide layer formed on the surface of the material. However, in the flue gas with SO_2, hot corrosion appears in the steel, with internal oxidation and sulfidation in the base metal; micro-cracks form in the corrosion layer and corrosion products peel off from the surface when the SO_2 volume fraction reaching 0.5%.
引文
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