稀土镧对700MPa级汽车板材高强钢耐海洋大气腐蚀性能的影响研究

Effect of rare element La on the corrosion resistance of high strength steel in 700 MPa grade automobile plate

通过周期浸泡加速腐蚀实验研究700 MPa级稀土钢和非稀土钢在模拟海洋大气环境的耐腐蚀性能.利用SEM和EDS研究了两者腐蚀形貌和锈层特征,利用失重法和电化学方法对两者的腐蚀速率进行比较.结果表明:稀土钢的腐蚀速率小于非稀土钢的腐蚀速率,且腐蚀形貌也不相同.随着稀土含量的增加,稀土钢的自腐蚀电流密度降低,有利于钢基体表面的电化学反应速率放缓,腐蚀倾向降低,从而提高稀土钢的耐腐蚀性能.

The corrosion resistance of the rare earth steel and non rare earth steel of 700 MPa grade in the simulated marine atmospheric environment was studied by the accelerated corrosion experiment. The corrosion morphology and rust layer characteristics of both steel were studied by using SEM and EDS, and their corrosion rates were compared. The results show that the corrosion rate of the rare earth steel is less than that of the non-rare earth steel, and their corrosion morphology is different. With the increase of the rare earth content, the self corrosion current density of the rare earth steel decreased, which is beneficial to the electrochemical reaction rate of the steel substrate and the corrosion tendency, so the corrosion resistance of the rare earth steel is improved.