High corrosion-resistant, high-strength and non-magnetic stainless steel, high corrosion-resistant, high-strength and non-magnetic stainless steel product and method for producing the same

Abstract

The present invention provides a high corrosion-resistant, high-strength and non-magnetic stainless steel containing: C: 0.01% to 0.05% by mass, Si: 0.05% to 0.50% by mass, Mn: more than 16.0% by mass but 19.0% by mass or less, P: 0.040% by mass or less, S: 0.010% by mass or less, Cu: 0.50% to 0.80% by mass, Ni: 3.5% to 5.0% by mass, Cr: 17.0% to 21.0% by mass, Mo: 1.80% to 3.50% by mass, B: 0.0010% to 0.0050% by mass, O: 0.010% by mass or less, and N: 0.45% to 0.65% by mass, with the balance substantially composed of Fe and unavoidable impurities, the steel satisfying the following equations (1) to (4): [Cr]+3.3×[Mo]+16×[N]≧30   (1) [Cr]/[C]≧330   (2) [Cr]/[Mn]>1.0   (3) ([Ni]+3×[Cu])/([Cr]+[Mo])>0.25   (4) wherein [Cr], [Mo], [N], [C], [Mn], [Ni] and [Cu] represent the content of Cr, the content of Mo, the content of N, the content of C, the content of Mn, the content of Ni, and the content of Cu in the steel in terms of mass %, respectively.

1 . A high corrosion-resistant, high-strength and non-magnetic stainless steel comprising:
 C: 0.01% to 0.05% by mass,   Si: 0.05% to 0.50% by mass,   Mn: more than 16.0% by mass but 19.0% by mass or less,   P: 0.040% by mass or less,   S: 0.010% by mass or less,   Cu: 0.50% to 0.80% by mass,   Ni: 3.5% to 5.0% by mass,   Cr: 17.0% to 21.0% by mass,   Mo: 1.80% to 3.50% by mass,   B: 0.0010% to 0.0050% by mass,   O: 0.010% by mass or less, and   N: 0.45% to 0.65% by mass,   with the balance substantially composed of Fe and unavoidable impurities, the steel satisfying the following equations (1) to (4):
   [Cr]+3.3×[Mo]+16×[N]≧30   (1) 
   [Cr]/[C]≧330   (2) 
   [Cr]/[Mn]>1.0   (3) 
   ([Ni]+3×[Cu])/([Cr]+[Mo])>0.25   (4) 
   wherein [Cr], [Mo], [N], [C], [Mn], [Ni] and [Cu] represent the content of Cr, the content of Mo, the content of N, the content of C, the content of Mn, the content of Ni, and the content of Cu in the steel in terms of mass %, respectively.   
     
     
         2 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 1 , which further comprises at least one element selected from the group consisting of Ca, Mg and REM in a total content of 0.0001% to 0.0100% by mass. 
     
     
         3 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 1 , which further comprises at least one element selected from the group consisting of Nb, V, Ta and Hf in a total content of 0.1% to 2.0% by mass. 
     
     
         4 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 2 , which further comprises at least one element selected from the group consisting of Nb, V, Ta and Hf in a total content of 0.1% to 2.0% by mass. 
     
     
         5 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 1 , which further comprises Al in a content of 0.001% to 0.10% by mass. 
     
     
         6 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 2 , which further comprises Al in a content of 0.001% to 0.10% by mass. 
     
     
         7 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 3 , which further comprises Al in a content of 0.001% to 0.10% by mass. 
     
     
         8 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 4 , which further comprises Al in a content of 0.001% to 0.10% by mass. 
     
     
         9 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 1 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         10 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 2 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         11 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 3 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         12 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 4 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         13 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 5 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         14 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 6 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         15 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 7 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         16 . The high corrosion-resistant, high-strength and non-magnetic stainless steel according to  claim 8 , which further comprises at least one member selected from the group consisting of W and Co in a total content of 0.1% to 3.0% by mass. 
     
     
         17 . A method for producing a high corrosion-resistant, high-strength and non-magnetic stainless steel product, which comprises subjecting the steel according to  claim 1  to working under a temperature condition of 300° C. to 900° C. at a reduction of area of 15% to 40%. 
     
     
         18 . A high corrosion-resistant, high-strength and non-magnetic stainless steel product obtained by subjecting the steel according to  claim 1  to working under a temperature condition of 300° C. to 900° C. at a reduction of area of 15% to 40%.