宁波地区自然环境对铁塔材料力学性能的影响

在加速腐蚀的基础上,通过对Q345铁塔材料的静强度和疲劳试验,研究了宁波地区大气腐蚀环境对Q345铁塔材料力学性能的影响。试验表明,5 a内的加速腐蚀对Q345镀锌材料静强度的影响可以忽略;Q345镀锌材料在当量腐蚀前4 a,腐蚀的形式为均匀腐蚀与点蚀共存;当量加速腐蚀1 a后的疲劳强度无显著降低;加速腐蚀3 a后疲劳强度降低6.2%;4 a后疲劳强度降低12.7%,对应在95%置信度和95%可靠度下的寿命则分别降低25%和46.5%;加速腐蚀第5年,由于均匀腐蚀的发生,削减了腐蚀坑深度,使得其对＂腐蚀坑深度＂敏感的疲劳强度与第4年相同。

Effect of Natural Environment of Ningbo Area on Mechanical Performance of Iron Tower

Based on accelerated corrosion test,the effect of environment of Ningbo area on mechanical performance of galvanized Q345 was studied.The test results showed that the effect of five years corrosion on fracture strength could be neglected;after accelerated corrosion for four years,uniformity and pit corrosion exist;the fatigue strength after accelerated corrosion for one year and the fatigue strength without corrosion are statistically the same;after accelerated corrosion for three years and four years,the fatigue strength is 6.2% and 12.7% less than the fatigue strength without corrosion,and the fatigue life is 25% and 46.5% less than the fatigue life without corrosion.The fatigue strength after accelerated corrosion for five years and the fatigue strength after accelerated corrosion for four years are statistically the same because uniform corrosion cuts the depth of corrosion pit that evidently effects fatigue strength.