Two-way shape-recovery alloy

Abstract

The present invention provides a two-way shape-recovery alloy, which contains less than 0.20 mass % of C, 13.00 to 30.00 mass % of Mn, 0.10 to 6.00 mass % of Si, 0.05 to 12.00 mass % of Cr, 0.01 to 3.00 mass % of Ni, and less than 0.100 mass % of N, with the remainder being Fe and unavoidable impurities, in which the contents of Mn, Si, Cr and Ni satisfy the following expression (1): 600≦33Mn+11Si+28Cr+17Ni≦1050  (1).

1 . A two-way shape-recovery alloy, which comprises:
 less than 0.20 mass % of C,   13.00 to 30.00 mass % of Mn,   0.10 to 6.00 mass % of Si,   0.05 to 12.00 mass % of Cr,   0.01 to 3.00 mass % of Ni, and   less than 0.100 mass % of N,   with the remainder being Fe and unavoidable impurities,   wherein the contents of Mn, Si, Cr and Ni satisfy the following expression (1):
   600≦33Mn+11Si+28Cr+17Ni≦1050  (1). 
   
     
     
         2 . The two-way shape-recovery alloy according to  claim 1 ,
 wherein the difference (A f −M s ) between a transformation finish temperature in heating (A f  point) and a transformation start temperature in cooling (M s  point) is 150° C. or smaller, and   wherein the alloy has a transformation start temperature in heating (A s  point) of 100° C. or higher.   
     
     
         3 . The two-way shape-recovery alloy according to  claim 1 , which further comprises at least one of
 0.10 to 2.00 mass % of Mo,   0.10 to 2.00 mass % of W,   0.05 to 1.00 mass % of V, and   0.10 to 5.00 mass % of Co.   
     
     
         4 . The two-way shape-recovery alloy according to  claim 2 , which further comprises at least one of:
 0.10 to 2.00 mass % of Mo,   0.10 to 2.00 mass % of W,   0.05 to 1.00 mass % of V, and   0.10 to 5.00 mass % of Co.   
     
     
         5 . The two-way shape-recovery alloy according to  claim 1 , which further comprises
 0.10 to 1.00 mass % of Cu+Al,   wherein the content of Ni and the total content of Cu+Al satisfies the following relationship:
   Ni≧(Cu+Al). 
   
     
     
         6 . The two-way shape-recovery alloy according to  claim 2 , which further comprises
 0.10 to 1.00 mass % of Cu+Al,   wherein the content of Ni and the total content of Cu+Al satisfies the following relationship:
   Ni≧(Cu+Al). 
   
     
     
         7 . The two-way shape-recovery alloy according to  claim 3 , which further comprises
 0.10 to 1.00 mass % of Cu+Al,   wherein the content of Ni and the total content of Cu+Al satisfies the following relationship:
   Ni≧(Cu+Al). 
   
     
     
         8 . The two-way shape-recovery alloy according to  claim 4 , which further comprises
 0.10 to 1.00 mass % of Cu+Al,   wherein the content of Ni and the total content of Cu+Al satisfies the following relationship:
   Ni≧(Cu+Al).