拉伸变形量对热镀锌合金化钢板耐蚀性能的影响  

Effect of drawing deformation on corrosion resistance of galvannealed steel sheets

作　　者：郭大伟[1] 袁训华[1] 顾宝珊[1] 张庭君 杜成 江社明[1] 张启富[1] 

机构地区：[1]钢铁研究总院先进金属材料涂镀国家工程实验室,北京100081 [2]新冶高科技集团有限公司,北京100081

出　　处：《材料热处理学报》2013年第8期153-157,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51071052);国家"十二五"科技支撑项目(2012BAJ13B03);北京市科技计划项目(D07010300700702)

摘　　要：通过在热镀锌合金化(GA)钢板上施加10%、20%、30%的单向拉伸应变量,得到了变形量不同的合金化镀层。用动电位极化法和电化学阻抗图谱法测得了不同变形量的合金化镀层在3.5%NaCl溶液中的腐蚀行为,用SEM观察了变形量不同的合金化镀层腐蚀前后的表面形貌。结果表明,合金化镀层的电化学阻抗随拉伸变形量的增大而变小,在拉伸的初始阶段阻抗值下降尤为明显,腐蚀电流是先减小后增大,说明GA镀层的变形量为10%时,镀层电容具有较高的保持电荷的能力。变形后的试样优先在裂纹内部发生点蚀,腐蚀深度和面积随形变量的增加而增大。当变形量达到30%时,镀层表面的裂纹已经增大到不具备优先发生腐蚀的尺寸。Deformed galvannealed steel sheets （GA） was prepared by 10% ,20% and 30% uniaxial tensile strain. Corrosion behavior of the deformed GA steel sheets in 3.5% NaC1 solution was examined by means of potentiodynamie polarization and electrochemical impedance spectroscopy, and the morphology of the coatings surface before and after corrosion was characterized by scanning electron microscopy. The results show that with the degree of deformation increase, the ahernating-eurrent impedance decreases, and the impedance value decreases remarkably in the initial stage of deformation, corrosion current of the GA coatings first decrease and then increase, which indicates that GA coating has high keeping charge ability when the deformation is 10%. Pitting corrosion occurs within the cracks of deformed GA coatings preferentially, corrosion depth and area was increase with deformation increasing. The width of the cracks on surface of GA coatings is not performed as the corrosion attack origin when the deformation is 30%.

关 键 词：单向拉伸 极化曲线 阻抗谱 表面形貌 GA镀层 

分 类 号：TG174.44[金属学及工艺—金属表面处理]