腐蚀损伤对Q345钢材力学性能的影响

Effects of Corrosion Damage on the Mechanical Properties of Q345 Steel

根据重庆地区年降雨时间及其分布特点,结合经典概率理论及统计知识建立降雨概率分布模型,基于此模型,结合钢材腐蚀特征建立环境腐蚀损伤试验模型;然后,根据重庆酸雨成分及其含量配置高浓度模拟酸雨溶液,对5组共计19个Q345钢材材性试件进行不同时间的"间浸"式腐蚀损伤试验,观察分析试件在腐蚀环境中的破坏形态;最后,对各组腐蚀试件开展拉拔试验,由腐蚀试件屈服强度、极限抗拉强度、弹性模量以及伸长率等材料力学性能参数的变化情况,分析Q345钢材力学性能参数随腐蚀损伤的退化规律。结果表明:Q345钢材屈服强度和极限抗拉强度等承载力参数随腐蚀损伤增加而退化,加速腐蚀84 h后分别退化了10.67%和8.83%,部分试件甚至出现屈服平台消失;与承载力参数相比,弹性模量、截面收缩率、伸长率等衡量构件变形能力的参数退化最为显著,退化率约20%。

A corrosion mode of acid rain was proposed by combining the probability distribution model with metal corrosion characteristics. And then,in the high concentration simulation acid rain solution,the corrosion pattern and failure modes of 19 specimens of Q345 steel with different corrosion damage was observed by the proposed corrosion mode. At last,through the materials quality testing,the bearing capacity and deformability of Q345 specimens with different corrosion damage was studied. Results：（ 1） According to the parameter of undamaged specimens,these parameters to measure the bearing capacity of Q345 specimens with different corrosion damage,such as yield strength and ultimate tensile strength,were obviously degenerated,and even the yield platform of some specimens disappeared in the constitutive curve.（ 2） Compared with the parameters of the bearing capacity,the parameters which reflect Q345 specimens＇ deformability,such as elastic modulus,elongation,sectional shrinkage and so on,were more seriously degenerated. And the degeneration rate of some parameters reached 20%.