Ferritic stainless steel sheet excellent in surface gloss and corrosion resistance and method for producing same

Abstract

The stainless steel sheet according to the present invention is a ferritic stainless steel which is comprised of, by mass %, C: 0.001 to 0.03%, Si: 0.01 to 1.0%, Mn: 0.01 to 1.5%, P: 0.005 to 0.05%, S: 0.0001 to 0.01%, Cr: 12 to 16%, N: 0.001 to 0.03%, Nb: 0.05 to 0.3%, Ti: 0.03 to 0.15%, Al: 0.005 to 0.5%, Sn: 0.01 to 1.0%, and has the remainder of Fe and unavoidable impurities and satisfies the relationship of 1≦Nb/Ti≦3.5. The method comprises heating a slab of stainless steel which contains the above steel ingredients, setting the extraction temperature 1080 to 1190° C., and setting the coiling temperature after the end of hot rolling 500 to 700° C. After hot rolling, the method comprises annealing the hot rolled sheet, which can be omitted, cold rolling once or cold rolling twice or more which includes processing annealing, and finish annealing the steel sheet at 850 to 980° C.

1 . A ferritic stainless steel sheet which is excellent in surface gloss and corrosion resistance, comprising: by mass %,
 C: 0.001 to 0.03%,   Si: 0.01 to 1.0%,   Mn: 0.01 to 1.5%,   P: 0.005 to 0.05%,   S: 0.0001 to 0.01%,   Cr: 12 to 16%,   N: 0.001 to 0.03%,   Nb: 0.05 to 0.3%,   Ti: 0.03 to 0.15%,   Al: 0.005 to 0.5%, and   Sn: 0.01 to 1.0%;   the steel sheet having the remainder being Fe and unavoidable impurities, and satisfying the relationship of 1≦Nb/Ti≦3.5.   
     
     
         2 . The ferritic stainless steel sheet which is excellent in surface gloss and corrosion resistance as set forth in  claim 1 , wherein said stainless steel sheet further contains, by mass %, one element or more of
 Ni: 0.01 to 0.5%,   Cu: 0.01 to 0.5%,   Mo: 0.01 to 0.5%,   V: 0.01 to 0.5%,   Zr: 0.01 to 0.5%,   Co: 0.01 to 0.5%,   Mg: 0.0001 to 0.005%,   B: 0.0003 to 0.005%, and   Ca: 0.0003 to 0.005%.   
     
     
         3 . A method of production of a ferritic stainless steel sheet which is excellent in surface gloss and corrosion resistance, comprising of: heating a slab of stainless steel which contains the steel ingredients described in  claim 1 , taking out the slab from the heating furnace at an extraction temperature of 1080 to 1190° C., and hot rolling and coiling the steel sheet at a temperature of 500 to 700° C. 
     
     
         4 . The method of production of the ferritic stainless steel sheet which is excellent in surface gloss and corrosion resistance as set forth in  claim 3 , comprising of:
 coiling the steel sheet in hot rolling, cold rolling, and finish annealing the steel sheet at 850 to 980° C.   
     
     
         5 . The method of production of the ferritic stainless steel sheet which is excellent in surface gloss and corrosion resistance as set forth in  claim 3 , comprising of:
 coiling the steel sheet in hot rolling, cold rolling twice or more which includes processing annealing, and finish annealing the steel sheet at 850 to 980° C.   
     
     
         6 . The method of production of the ferritic stainless steel sheet which is excellent in surface gloss and corrosion resistance as set forth in  claim 4 , comprising of: coiling the steel sheet in hot rolling, and annealing the hot rolled sheet at an annealing temperature of in the range of the recrystallization temperature to 1050° C. before cold rolling.