低合金高强度钢的耐模拟工业大气腐蚀行为研究

2021-08-12 15:15:08 作者：孙永伟来源：中国腐蚀与防护学报分享至：

摘要

选择Q345E和Cr-Ni-Cu两种典型的低合金高强度钢，在0.052% （质量分数） NaHSO3水溶液中进行极化实验和间浸挂片实验，比较了两种钢的腐蚀速率，评价了两种钢的耐蚀性。利用SEM和XRD分析两种钢的腐蚀形貌，锈层结构及其相组成。结果表明，Q345E和Cr-Ni-Cu钢的腐蚀电位分别为-730和-705 mV；两种钢的腐蚀锈层物相均含有γ-FeO（OH）和少量的α-Fe，随腐蚀时间延长，存在少量α-FeO（OH）和Fe3O4。Cr-Ni-Cu钢相比Q345E钢，其腐蚀速率较低，Cr，Ni和Cu等元素的存在提高了其耐蚀性能；Cr-Ni-Cu钢的表面锈层比Q345E钢更加致密，锈层微裂纹更少。

关键词：低合金高强度钢 ; 大气腐蚀 ; 锈层特征 ; 间浸腐蚀 ; 腐蚀速率

Abstract

The corrosion resistance of Q345E and Cr-Ni-Cu steels was comparatively assessed by means of potentiodynamic polarization and cyclic immersion corrosion tests in 0.052% （mass fraction） NaHSO3 solution, which aims to simulate the common SO2-containing atmosphere. The characteristic of corrosion rust was studied by means of scanning electron microscope （SEM） and X-ray diffraction （XRD）。 Results show that the open circuit corrosion potential of Q345E and Cr-Ni-Cu steel are -730 and -705 mV, respectively. The rust layers of two steels contain γ-FeO（OH） and α-Fe phase. Some α-FeO（OH） and Fe3O4 products generate with increasing of the corrosion time. Compared with Q345E steel, the Cr-Ni-Cu steel has lower corrosion rate due to the formation of a much more compact rust layer containing elements such as Cr, Ni and Cu, which are beneficial to corrosion resistance.

Keywords： low-alloy high strength steel ; atmospheric corrosion ; rust characteristic ; cyclic immersion corrosion ; corrosion rate