Q345R钢在模拟地热水环境中的腐蚀与结垢

针对地热资源利用过程中钢管材料出现的腐蚀结垢问题,模拟某处地热水的环境条件,探讨了Q345R钢在30、60、90℃下的腐蚀和结垢规律。实验结果表明,随着温度上升,材料的腐蚀电位逐渐下降,极化曲线的斜率变大,腐蚀电化学速率增加,耐腐蚀性随温度升高而下降;在60℃的模拟地热水溶液中,试样表面生成了致密的Fe3O4保护膜,阻碍了金属腐蚀;而在90℃的模拟地热水溶液中,试样表面生成的Fe2O3膜结垢稀疏,对试样保护作用较弱;在30℃的模拟地热水溶液中,试样表面产生大量的CaCO3垢层;而在60℃的模拟地热水溶液中,试样表面产生的CaCO3垢层最少;腐蚀后的试样的力学性能比原始试样略有下降,但程度不大,并且温度越高,试样力学性能越差。

Corrosion and Scaling of the Q345R Steel in Simulated Geothermal Water

Corrosion and scaling are common troubles in the geothermal application . The geothermal water of a region is simulated to examine the corrosion and scaling behavior of Q345R steel at 30 ℃ ,60 ℃ and 90 ℃ .The results show that the corrosion potential of steels reduces gradually and the electrochemical corrosion rate speeds up along with the increase of temperature .The slope of polarization curves increases when temperature increases . In the immersion test of 60 ℃ ,there is the seal Fe3O4 scaling layer on the surface of steels ,which has good protective effect on steels in the middle of immersion .In the immersion test of 90 ℃ ,the Fe2 O3 scaling layer on the surface of steels cannot protect materials well .In the immersion test of 30 ℃ , there is a large amount of CaCO3 scaling layer on the surface of steels , w hile in the immersion test of 60 ℃ ,there is only minimum CaCO3 scaling layer on the surface of steels .The mechanical property of the samples after corrosion is a little reduced ,which is not obvious and becomes worse when the temperature increases .