为探讨磷复肥工业生产余热利用环境对汽轮机转子的腐蚀行为影响,通过失重法、激光共聚焦显微镜(CLSM)、扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、X射线光电子能谱(XPS)、电化学测试等表征手段,研究了汽轮机转子材料2Cr-1Ni-1.2Mo-0.2V钢在外界温度为25 ℃的120 mmol/L NH4H2PO4溶液中的腐蚀行为与规律。结果表明:2Cr-1Ni-1.2Mo-0.2V钢发生均匀腐蚀,且其腐蚀速率先快速减小后缓慢减小,并逐渐趋于0.2 mm/a 稳定。2Cr-1Ni-1.2Mo-0.2V钢在NH4H2PO4浓度为120 mmol/L,温度为25 ℃环境下的服役寿命为7.5 a。2Cr-1Ni-1.2Mo-0.2V钢在NH4H2PO4溶液中生成的腐蚀产物膜主要由Fe3(PO4)2、FePO4、Fe(OH)3、FeOOH、Fe3O4构成,随着浸泡时间的延长,腐蚀产物膜的覆盖度、致密度和厚度等增大,腐蚀产物膜中Cr出现富集,一定程度提高了材料的耐蚀性。
王通, 李全德, 李智, 陈瑞芳, 龚显龙, 戴君, 倪荣, 巩秀芳, 隆彬, 孟惠民
. 2Cr-1Ni-1.2Mo-0.2V钢在120 mmol/L NH4H2PO4溶液中的腐蚀行为[J]. 材料保护, 2023
, 56(12)
: 179
-187
.
DOI: 10.16577/j.issn.1001-1560.2023.0303
In order to analyze the impact of the waste heat utilization environment in phosphate compound fertilizer industrial production on the corrosion behavior of steam turbine rotors, various methods such as the mass loss method, laser scanning confocal microscopy (CLSM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical tests were employed. The corrosion behavior and patterns of the steam turbine rotor material, 2Cr-1Ni-1.2Mo-0.2V steel in 120 mmol/L NH4H2PO4 solution at an external temperature of 25 ℃ were investigated. Results showed that 2Cr-1Ni-1.2Mo-0.2V steel underwent uniform corrosion. The corrosion rate first rapidly decreased and then slowly decreased, gradually stabilizing towards 0.2 mm/a. When the NH4H2PO4 concentration was 120 mmol/L and the temperature was 25 ℃, the service life of 2Cr-1Ni-1.2Mo-0.2V steel was determined to be 7.5 a. The corrosion product film of 2Cr-1Ni-1.2Mo-0.2V steel in NH4H2PO4 solution was composed of Fe3(PO4)2, FePO4, Fe(OH)3, FeOOH, and Fe3O4. As the immersion time prolonged, the coverage, compactness and thickness of the corrosion product film were observed to increase, and Cr was found to be enriched in the corrosion product film, thereby enhancing the corrosion resistance of 2Cr-1Ni-1.2Mo-0.2V steel.
