| 摘要 |
<p>The prod. is made starting from molten steel contg. 0.2-1% C, 0.5% Si, >10% Cr, other alloying elements, and treated by the steps:- (a) inert gas at 1-15, esp. 5-15 N1/minute/tonne, is blown into the melt in a ladle, while a gentle stream of O2, esp. 1-11.5 Nm3/hour/tonne, is blown onto the surface of the melt, esp. from a lance 1/2 - 1 1/2 m above the bath surface, until the bath contains 0.025-0.05% carbon, (b) the injection of inert gas is continued under a vacuum harder than 10 torr so a reaction-active surface ratio (RASR) over 7% is obtd. in order to reduct the carbon to below 0.003%. The RASR is the % of fresh bath surface obtd. by injection of inert gas as compared with the total bath surface. Used to mfr. ferritic stainless steels with exceptionally high resistance to corrosion, and extremely high toughness.</p> |
