Experimental study on low temperature fatigue performance of polar icebreaking ship steel

The low-temperature mechanical properties and low-temperature fatigue properties of polar icebreakers steel are the key to ensure the safe operation of polar icebreakers under low temperature conditions. The main material of the polar icebreaker “Snow DragonⅠ” is EH36 steel due to its good impact toughness and low temperature resistance. In this paper, the tensile experiments and fatigue behavior of EH36 steel used in “Snow Dragon” under different temperatures are studied. The mechanical properties and low-temperature fatigue crack growth characteristics of the material were obtained. The experimental results show that the yield strength, tensile limit, elongation, and cross-sectional shrinkage will increase to varying degrees with decreasing temperature. As the temperature decreases, the plasticity of EH36 steel decreases and the brittleness increases. The fatigue crack growth rate of EH36 steel is lower at low temperature than normal room temperature. The fatigue crack growth threshold at low temperatures is higher than the room temperature threshold. Good resistance to crack initiation and crack growth of EH36 steel at low temperature are verified by the experiments. •From the experiments, EH36 steel has better low-temperature mechanical properties.•The fatigue life of E36 is affected by the ratio under different experimental temperature.•The effect of temperature on fatigue crack growth threshold is more significant.•The fatigue crack growth rate of EH36 steel increases with the decrease of the temperature.