Other

Armco Inc.

Alan R McKague

Eizo Yoshitake

A ferritic non-ridging stainless steel and process therefor. A chromium alloyed steel melt containing sufficient titanium and nitrogen but a controlled amount of aluminum is cast into an ingot or continuously cast into a strip or a slab having an as-cast fine equiaxed grain structure substantially free of columnar grains. The as-cast steel contains 0.08% C, at least about 8% Cr, up to 1.50% Mn, &#x3c;0.020% Al, &#x2266;0.05% N, &#x2266;1.5% Si, &#x3c;2.0% Ni, Ti&#x2267;0.10%, the ratio of (Ti&#xd7;N)/Al&#x2267;0.14, all percentages by weight, the balance Fe and residual elements. Preferably, the titanium is controlled so that (Ti/48)/[(C/12)+(N/14)]&#x3e;1.5. A hot processed sheet may be formed from a continuously cast slab without grinding the surfaces of the slab. The hot processed sheet may be descaled, cold reduced to a final thickness and recrystallization annealed. Annealing the hot processed sheet prior to cold reduction is not required to obtain an annealed sheet essentially free of ridging and having high formability.

Non-ridging ferritic chromium alloyed steel

A ferritic non-ridging stainless steel and process therefor. A chromium alloyed steel melt is deoxidized with a sub-equilibrium amount of titanium and nitrogen and continuously cast into a strip or a slab or cast into an ingot having an as-cast fine equiaxed microstructure substantially free of columnar grains. The as-cast steel contains .ltoreq.0.010% Al, up to 0.08% C, 0.10-1.50% Mn, .ltoreq.0.05% N, .ltoreq.1.5% Si, 8-25% Cr, &lt;2.0% Ni and is deoxidized with titanium, all percentages by weight, the balance Fe and residual elements. Preferably, the titanium is controlled so that (Ti/48)/�(C/12)+(N/14)!&gt;1.5. A hot processed continuous sheet may be formed from a continuously cast slab without surface grinding, may be descaled, cold reduced to a final thickness and recrystallization annealed. An anneal prior to cold reduction is not required to obtain an annealed sheet essentially free of ridging.

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Monroe, OH, United States of America

Alan R McKague