塔筒钢在模拟海洋环境下的慢应变拉伸性能研究

模拟在海洋环境下,采用慢应变速率拉伸试验研究海上风电机组塔筒钢Q345钢在不同应变速率、不同浓度NaCl溶液和不同温度条件下的应力腐蚀行为。实验结果表明:随着拉伸速率的减小,Q345钢在NaCl溶液中的应力腐蚀敏感性基本呈单调增加的趋势,当拉伸速率为4×10-7s-1时,试样已发生应力腐蚀开裂;环境介质的存在使得该材料的抗拉强度、总应变和断裂能大大降低,且随NaCl溶液浓度的增加,Q345钢的应力腐蚀开裂敏感性增加。温度对材料的应力腐蚀行为的影响较大,随着温度的升高,塑性指标下降明显,敏感性指数增加明显,当温度为50℃时,具有明显的应力腐蚀倾向。

STUDY ON SLOW STRAIN RATE TENSILE PROPERTIES OF TOWER TUBE STEEL IN SIMULATED OCEAN ENVIRONMENT

The influence of stretch rate,the concentration of the NaCl solution and the temperature in the solution on the stress corrosion cracking of Q345 steel for offshore wind turbine tower was investigated by means of the slow strain rate tensile test. The experimental results show that the stress corrosion susceptibility of Q345 steel in NaCl solution tends to increase monotonically with the decrease of the tensile rate. When the tensile rate is 4×10-7s-1,the specimen has undergone stress corrosion cracking. The environmental medium greatly reduces the tensile strength,total strain and fracture energy of the Q345 steel. And the sensitivity of stress corrosion cracking of Q345 steel increases with the increase of NaCl concentration. The effect of temperature on the stress corrosion susceptibility of the material is large,and the sensitivity index increased significantly with the increase of temperature. When the temperature is 50 ℃,it has obvious stress corrosion tendency.