Super304H钢在含1.5％SO2模拟烟气中的腐蚀行为研究

目的研究Super304H钢在650℃和700℃模拟烟气中的腐蚀行为和机理。方法将Super304H钢试样置于含SO2(体积分数1.5%)的模拟烟气中,间隔一定时间取出样品称量,获得腐蚀动力学曲线。采用XRD、SEM和EDS分析不同腐蚀阶段的腐蚀产物形貌、成分和物相组成。结果腐蚀初期,Super304H钢在700℃下的腐蚀速率明显比650℃下的快,腐蚀过程中,腐蚀产物不断生成和剥落。650℃时,样品初期的主要成分为Cr_2O_3和Fe2O3,随腐蚀时间的延长,生成了Fe_3O_4;700℃时的腐蚀产物剥落更明显。腐蚀产物具有双层结构,主要由Fe2O3、Cr_2O_3、Fe_3O_4和少量(Ni,Cr)Fe_2O4、Cu Fe_2O4尖晶石类化合物组成,在腐蚀产物内层生成了硫化物。结论 Super304H钢在650℃和700℃含SO2(1.5%)的模拟烟气中,腐蚀产物不断生成和剥落,导致腐蚀加速。

Corrosion Behavior of Super304H Steel in 1.5% SO2 Simulated Fuel Gas

The work aims to study corrosion behavior and mechanism of Super304H steel in simulated fuel gas at 650 ℃and 700 ℃, respectively. The Super304H steel was placed in simulated fuel gas containing SO2 (volume fraction 1.5%), corrosion kinetics curves were obtained by weighting the sample at intervals. Morphology, composition and phase composition of the corrosion product at different corrosion stages were analyzed with XRD, SEM and EDS. At the initial corrosion stage, corrosionrate of Super304H steel at 700 ℃ was faster than that at 650 ℃. Continuous formation and peeling of corrosion product wereobserved during the corrosion process. Main constituents of the sample at the initial stage were identified as Cr2O3 and Fe2O3 at650 ℃, then Fe3O4 was generated as the corrosion time prolonged. When the sample was corroded at 700 ℃, corrosion productpeeled off more evidently. The corrosion product had a bilayer structure and it was mainly composed of Fe2O3, Cr2O3, Fe3O4 and a small amount of spinel compounds including (Ni,Cr)Fe2O4and CuFe2O4. Sulfide formed in internal layer of the corrosion product. When Super304H steel is placed in the simulated fuel gas containing SO2(1.5 vol%) at 650℃ and 700 ℃, corrosion rate accelerates as the corrosion products form and peel off continuously.