正火消除带状组织对20G耐蚀性影响研究

Effects of Banded Structures Relaxation via normalization on Corrosion Resistance of 20G steel

旨在解决特定腐蚀环境中,带状组织导致20G无缝钢管腐蚀加剧问题,作者采用均匀设计法对其热处理,结合SPSS软件回归分析和实验验证获得能够控制或消除其带状组织的最优热处理工艺(正火:10℃/min加热至920℃下保温40min风冷);并辅以动电位极化曲线和SECM研究了带状组织对20G在模拟地层水环境中的电化学腐蚀行为影响,同时结合SEM和XRD表征腐蚀产物,发现20G带状组织级别越低,其自腐蚀电位越正、阳极电流密度越低且腐蚀产物形貌对耐蚀性越有利。从而证明适当的正火热处理消除带状组织对提高20G耐蚀性效果显著。

Aimed at the problem of corrosion increased by banded structure in specific corrosive environment about 20G seamless tubes, a combination of uniform design for heat treatment, the software SPSS for data regression analysis and experimental verification is utilized to achieve eliminating banded structure by optimal heating processing（normalization： heating at 10℃/min, keeping920℃ for 40min, compulsive air cooling）; the corrosion behavior in a simulation formation water was obtained using potentiodynamic polarization curve andSECM, while microstructural study was conducted for the corrosion products by scanning electron microscopy（SEM）and X-ray diffraction（XRD）. The results indicate that corrosion potential turns positive, anodic current densitydecreases and morphology transformation ofcorrosion productsbenefits corrosion resistance with less banded structure. So with an appropriate normalization heat treatment, due to the removal of banded structure, corrosion resistance can be significantly improved.