EFFECT OF LOW-TEMPERATURE ON THE FATIGUE PROPERTIES OF TWO HSLA (HIGH STRENGTH LOW ALLOY) PIPELINE STEELS

In order to understand the fatigue behaviour of HSLA pipeline steels under low- temperature Arctic environments, a study has been undertaken to evaluate the influence of low-temperature on the high cycle fatigue behaviour of two candidate steels, namely (i) Cb Mo Acicular Ferrite steel developed by Climax-Ipsco and (ii) high-Cb HSLA steel developed by the Molybdenum Corporation of America. Results indicate that both the steels have reasonably good fatigue properties and that their fracture morphology and fatigue- induced dislocation substructures are quite complex. Design data based on room temperature htigue properties would be adequate for the low-temperature application of these steels.