Crack growth rates of structural steel in air and aqueous environments

Abstract The fatigue life of structural steel members depend largely on the fatigue crack growth rate. Crack growth rates were calculated in this study for mild and high strength Iow alloy (HSLA) steels, and quenched and tempered (QT) steels in three different environments—laboratory air, distilled water and a 3% saline solution. The data were gathered from published plots in literature. Linear regression lines from similar steel and environment were statistically compared, and similar sets were merged. Finally, four crack growth equations were obtained—HSLA and QT steels in air and aqueous environments. The crack growth rate in aqueous environments was about twice the rate in air. The air equations can be used for painted steel structures. The aqueous lines should be used for bare steel structures, such as those made from weathering steels.