Hot and corrosion-resistant steel

Abstract

The invention relates to metallurgy, more specifically to chromium- and nickel alloyed steels which are used in reactors (retorts) for magnesium-thermic production of spongy titanium. The inventive hot- and corrosion-resistant steel comprises iron (Fe) in the form of a base, carbon (C), nitrogen (N), manganese (Mn), silicium (Si), chromium (Cr), nickel (Ni), vanadium (V), at least one type of rare-earth metal (P3M) from a group of cerium (Ce), lanthanum (La), praseodymium (Pr), neodymium (Nd), said steel also contains titanium (Ti) and at least one element from a group of niobium (Nb), tantalum (Ta), zirconium (Zr) and hafnium (Hf) which are used in the form of carbide- and nitride solvents at the following component ratio, in mass %: C 0.04-0.15; N 0.01-0.25; Si 0.1-1.0; Mn 3.0-12.5; Cr 1.0-15.0; Ni 1.0-7.0; V 0.05-0.5; one or several elements of a group of Ce, La, Pr, Nd 0.0001-0.01; and Ti 0.1-2.0; and one or several elements of a group of Nb, Ta, Zr, Hf 0.05-0.2. Said invention makes it possible to increase the hot and corrosion-resistance in aggressive media used for the magnesium-theremic production of spongy titanium and to reduce the contamination thereof with detrimental impurities.

1 . Heat and corrosion resistant steel which besides iron (Fe) forming the basis, contains carbon (C), nitrogen (N), manganese (Mn), silicon (Si), chromium (Cr), nickel (Ni), vanadium (V), and at least one of the rare-earth metals of the cerium (Ce), lanthanum (La), praseodymium (Pr), neodymium (Nd) group, characterized in that it additionally contains titanium (Ti) and at least one element of the niobium (Nb), tantalum (Ta), zirconium (Zr), hafnium (Hf) group as carbide and nitride formers with the following relationship of the elements (in mass percent): 
     
       
         
               
               
             
                   
               
                 C 
                 0.04-0.15; 
               
                 N 
                 0.01-0.25; 
               
                 Si 
                 0.1-1.0; 
               
                 Mn 
                 3.0-12.5; 
               
                 Cr 
                 11.7-15.0; 
               
                 Ni 
                 1.0-3.8; 
               
                 V 
                 0.05-0.5; 
               
                 One or more rare-earth metals of the Ce, La, Pr, Nd 
                 0.0001-0.01; 
               
                 group 
               
                 Ti 
                 0.1-2.0; 
               
                 One or more elements of the Nb, Ta, Zr, Hf 
                 0.05-0.2; 
               
                 group 
               
                 Fe 
                 the rest