| 摘要 |
<p>An analyzing method of discolored portions on edge surfaces of a BAF(Batch Annealing Furnace) annealed cold rolled coil is provided to manufacture a high quality cold rolled coil having beautiful and uniform surface qualities by deriving a sample pre-treatment process and an etching process that can optimally analyze the surface state of the cold rolled coil and controlling process control factors. In an analyzing method of discolored portions on edge surfaces of a BAF annealed cold rolled coil, comprising: deriving a sample pre-treatment process and an etching process that can optimally analyze the surface state of the cold rolled coil with respect to the discolored portions on the edge surfaces of the BAF annealed cold rolled coil; and controlling process control factors by standardizing an operating method of a scanning electron microscope, thereby judging principal causes of discoloration from property information of fine oxide particles or a surface layer part of an organic carbide on the surface of the cold rolled coil through the analysis of constituents through the point identification, the analyzing method is characterized in that the cold rolled coil contains iron(Fe) as a principal material, and 0.05 to 0.08 wt.% of carbon(C), 0.01 to 0.02 wt.% of silicon(Si), 0.30 to 0.50 wt.% of manganese(Mn), 0.001 to 0.05 wt.% of phosphorous(P), and 0.001 to 0.05 wt.% of sulfur(S).</p> |
