ISO 12944-2:2017涉及钢结构暴露的主要环境的分类，以及这些环境的腐蚀性。ISO 12944-2:2017 -根据标准试样的质量损失（或厚度损失）定义大气腐蚀性类别，并描述钢结构暴露的典型自然大气环境，给出腐蚀性评估建议， -描述浸没在水中或埋在土壤中的结构的不同环境类别，以及 -提供一些特殊腐蚀应力的信息，这些应力可能会导致腐蚀速率显著增加或对保护漆系统的性能提出更高的要求。 与特定环境或腐蚀性类别相关的腐蚀应力代表了控制防护涂料系统选择的一个基本参数。

ISO 12944-2:2017 deals with the classification of the principal environments to which steel structures are exposed, and the corrosivity of these environments. ISO 12944-2:2017 - defines atmospheric-corrosivity categories, based on mass loss (or thickness loss) by standard specimens, and describes typical natural atmospheric environments to which steel structures are exposed, giving advice on the estimation of the corrosivity, - describes different categories of environment for structures immersed in water or buried in soil, and - gives information on some special corrosion stresses that can cause a significant increase in corrosion rate or place higher demands on the performance of the protective paint system. The corrosion stresses associated with a particular environment or corrosivity category represent one essential parameter governing the selection of protective paint systems.