| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably produce the blank for Fe-Ni base alloy cold-rolled sheet which can be used for shadow mask in high visibility and high brightness TV excellent in etching perforation. SOLUTION: It is a producing method where molten steel obtd. by refining in a converter 3 and molten Ni-containing crude metal obtd. by melting in a melting furnace 4 are combined to obtain the molten alloy containing 30-45 wt.% Ni. After heating the molten alloy, decarburization is executed under reduced pressure in an RH vacuum degassing apparatus 6, and after decarburizing, deoxidation is executed with Al, and successively casting is executed, and Al adding quantity in the Al deoxidation after decarburizing is regulated to <=3.0 kg/ton of molten alloy. Also, at least after Al deoxidation, CaO-Al2O3-MgO base slag containing >=57 wt.% CaO+Al2O3, <=25 wt.% MgO, <=15 wt.% SiO2 and <=3 wt.% the total oxide quantity of metals having the affinity with oxygen at the level weaker than that of Si and >=0.45 that is a ratio of CaO/(CaO+Al2 O3) is brought into contact with the molten alloy in the ladle.</p> |
