氧化铁皮微观组织对热轧带钢耐侯性能的影响

Effect of oxide scale microstructure on weathering resistance property of hot-rolled strip

通过加速腐蚀实验研究4种氧化铁皮组织对热轧带钢腐蚀性能的影响。实验结果表明,经过80周期的加速腐蚀后,组织由Fe_3O_4和FeO构成的氧化铁皮最耐腐蚀。组织由Fe_3O_4、共析产物(Fe_3O_4+Fe)构成的氧化铁皮耐腐蚀性能最差。在腐蚀初期,腐蚀产物在氧化铁皮表面的缺陷处优先形核,随后外锈层形成。随着外锈层逐渐长大,在氧化铁皮缺陷处形成的腐蚀产物的体积变大。氧化铁皮缺陷处会形成裂纹并扩展到基体,形成内锈层的腐蚀核。在腐蚀后期,外锈层厚度继续长大,结合面处的腐蚀核长大形成内锈层,这时氧化铁皮失去保护作用。

The corrosion behavior of a hot-rolled steel with four types of oxide scale was investigated by the dry and wet cyclic accelerated corrosion test.The test results for 80 cycles indicated that scale comprised wustite and magnetite had the strongest corrosion-resistance.The corrosion resistance of scale comprised magnetite/iron mixture and magnetite was weakest.It has been found that the comosion products are prior to nucleate on the defects of oxide scale,and grow into outer rust layer during the early stage.As the outer rust layer growing,the volume of corrision products become bigger.The cracks would form on the defects of oxide scale and grow to the matrix,which could be the corrosion core of inner rust layer.During the late stage the inner rust formed with the outer rust layer growing,by the growth of comosion core on the faying face.At the same time,oxide scale was lost protection function.