The effects of H_(2)SO_(4)concentration and current in electrochemical corrosion on surface layer softening or plasticizing of Q235 steel bar and their effects on subsequent electrochemical cold drawing(ECD)were inves...The effects of H_(2)SO_(4)concentration and current in electrochemical corrosion on surface layer softening or plasticizing of Q235 steel bar and their effects on subsequent electrochemical cold drawing(ECD)were investigated.The results indicate that the electrochemical corrosion can soften or plasticize the surface layer of Q235 steel bar and then make the subsequent ECD be conducted more easily.The softening degree and thickness of the surface layer are continuously enhanced with increasing corrosion rate,i.e.,increasing H_(2)SO_(4)concentration or current,due to the generation of more vacancy clusters in deeper regions of surface layer.These vacancy clusters then relax dislocations through being absorbed during ECD,and the formation and movement of additional dislocation flux are thereby enhanced,resulting in the further obvious decrease in the drawing force.It is also due to the enhanced formation and movement of additional dislocation flux that the dislocation density and thus the hardness of the surface layer are decreased,as well as that the texture structure is weakened.These behaviors are enhanced as the corrosion rate increases.展开更多
基金thanks for the National Natural Science Foundation of China(Grant No.51971105)for financial support,and P.Zhang and X.Z.Cao(the Positron Research Platform,Institute of High Energy Physics,CAS,Beijing 100049,China)for conducting the analysis of positron annihilation life spectroscopy.
文摘The effects of H_(2)SO_(4)concentration and current in electrochemical corrosion on surface layer softening or plasticizing of Q235 steel bar and their effects on subsequent electrochemical cold drawing(ECD)were investigated.The results indicate that the electrochemical corrosion can soften or plasticize the surface layer of Q235 steel bar and then make the subsequent ECD be conducted more easily.The softening degree and thickness of the surface layer are continuously enhanced with increasing corrosion rate,i.e.,increasing H_(2)SO_(4)concentration or current,due to the generation of more vacancy clusters in deeper regions of surface layer.These vacancy clusters then relax dislocations through being absorbed during ECD,and the formation and movement of additional dislocation flux are thereby enhanced,resulting in the further obvious decrease in the drawing force.It is also due to the enhanced formation and movement of additional dislocation flux that the dislocation density and thus the hardness of the surface layer are decreased,as well as that the texture structure is weakened.These behaviors are enhanced as the corrosion rate increases.
