1.1本指南介绍了估算低合金耐候钢耐大气腐蚀性的两种方法，如规范A242/A242M、A588/A588M、A606类型4、A709/A709M 50W、HPS 70W和100W、A852/A852M和A871/A871M中所述。一种方法是根据短期试验结果，估计特定地点钢材的长期厚度损失。另一种是根据化学成分估算相对耐腐蚀性。

1.1 This guide presents two methods for estimating the atmospheric corrosion resistance of low-alloy weathering steels, such as those described in Specifications A242/A242M, A588/A588M, A606 Type 4, A709/A709M grades 50W, HPS 70W, and 100W, A852/A852M, and A871/A871M. One method gives an estimate of the long-term thickness loss of a steel at a specific site based on results of short-term tests. The other gives an estimate of relative corrosion resistance based on chemical composition.