Low thermal expansion alloy

Abstract

[Problem] To obtain Alloy with low thermal expansion properties in the vicinity of room temperature to 800° C.[Solution] The low thermal expansion alloy of the present invention comprises, by mass %, Fe:20 to 60%, Ni:20 to 35%, Cr:0 to 30%, and the balance of Co and impurities.

1 . A low thermal expansion alloy comprising, by mass %,
 Fe:20 to 60%,   Ni:20 to 35%,   Cr:0 to 30%, and   the balance of Co and impurities.   
     
     
         2 . The low thermal expansion alloy according to  claim 1 , wherein the microstructure of the low thermal expansion alloy contains an austenite phase in an area ratio of 90% or more. 
     
     
         3 . The low thermal expansion alloy according to  claim 1 , wherein the low thermal expansion alloy contains Co of 20 mass % or more. 
     
     
         4 . The low thermal expansion alloy according to  claim 1 , wherein the low thermal expansion alloy contains Ni of 25 mass % or more. 
     
     
         5 . The low thermal expansion alloy according to  claim 3 , wherein the low thermal expansion alloy contains Ni of 25 mass % or more. 
     
     
         6 . The low thermal expansion alloy according to  claim 2 , wherein the low thermal expansion alloy contains Co of 20 mass % or more. 
     
     
         7 . The low thermal expansion alloy according to  claim 2 , wherein the low thermal expansion alloy contains Ni of 25 mass % or more.