Cr BASED TWO-PHASE ALLOY AND PRODUCT THEREOF

Abstract

An object of the invention is to provide a two-phase alloy which contains inexpensive Cr as a main component, and which is superior in strength properties including corrosion resistance and toughness, and in abrasion resistance to conventional ones under a high corrosion circumstance such as in an oil well. The invention is a Cr based two-phase alloy including two phases of a ferrite phase and an austenite phase in a mixed state, in which a chemical composition of the Cr based two-phase alloy consists of a major component, an accessory component, impurities, a first optional accessory component, and a second optional accessory component, and the major component consists of 33% by mass or more and 65% by mass or less of Cr, 18% by mass or more and 40% by mass or less of Ni, and 10% by mass or more and 33% by mass or less of Fe.

1 . A Cr based two-phase alloy comprising two phases of a ferrite phase and an austenite phase in a mixed state, wherein
 a chemical composition of the Cr based two-phase alloy consists of a major component, an accessory component, impurities, a first optional accessory component, and a second optional accessory component,   the major component consists of 33% by mass or more and 65% by mass or less of Cr, 18% by mass or more and 40% by mass or less of Ni, and 10% by mass or more and 33% by mass or less of Fe,   the accessory component consists of 0.1% by mass or more and 2% by mass or less of Mn, 0.1% by mass or more and 1.0% by mass or less of Si, 0.005% by mass or more and 0.05% by mass or less of Al, and 0.1% by mass or more and 5.0% by mass or less of Cu, and   the impurities contain more than 0% by mass and 0.04% by mass or less of P, more than 0% by mass and 0.01% by mass or less of S, more than 0% by mass and 0.03% by mass or less of C, more than 0% by mass and 0.02% by mass or less of N, and more than 0% by mass and 0.03% by mass or less of O.   
     
     
         2 . The Cr based two-phase alloy according to  claim 1 , wherein
 the first optional accessory component is 0.1% by mass or more and 3.0% by mass or less of Mo.   
     
     
         3 . The Cr based two-phase alloy according to  claim 1 , wherein
 the second optional accessory component consists of at least one of V, Nb, Ta and Ti, and   a total atomic content ratio of the V, Nb, Ta and Ti is in a range of 0.8 times or more and 2 times or less of a total atomic content ratio of the C, N and O.   
     
     
         4 . The Cr based two-phase alloy according to  claim 1 , wherein
 an occupation ratio of the ferrite phase is 10% or more and 95% or less.   
     
     
         5 . The Cr based two-phase alloy according to  claim 1 , wherein
 the component of Ni is in a range of 23% by mass or more and 40% by mass or less.   
     
     
         6 . The Cr based two-phase alloy according to  claim 5 , wherein
 the first optional accessory component is 0.1% by mass or more and 3.0% by mass or less of Mo.   
     
     
         7 . The Cr based two-phase alloy according to  claim 5 , wherein
 the second optional accessory component consists of at least one of V, Nb, Ta and Ti, and   the total atomic content ratio of the V, Nb, Ta and Ti is in a range of 0.8 times or more and 2 times or less of the total atomic content ratio of the C, N and O.   
     
     
         8 . The Cr based two-phase alloy according to  claim 5 , wherein
 an occupation ratio of the ferrite phase is 10% or more and 95% or less.   
     
     
         9 . A two-phase alloy product which is a product using a two-phase alloy, wherein
 the two-phase alloy is the Cr based two-phase alloy according to  claim 1 .   
     
     
         10 . A two-phase alloy product which is a product using a two-phase alloy, wherein
 the two-phase alloy is the Cr based two-phase alloy according to  claim 5 .   
     
     
         11 . The two-phase alloy product according to  claim 9 , wherein
 the product is a molded body having a forged structure.   
     
     
         12 . The two-phase alloy product according to  claim 10 , wherein
 the product is a molded body having a cast structure.   
     
     
         13 . The two-phase alloy product according to  claim 10 , wherein
 the product is a powder.   
     
     
         14 . The Cr based two-phase alloy according to  claim 2 , wherein
 the second optional accessory component consists of at least one of V, Nb, Ta and T 1 , and   a total atomic content ratio of the V, Nb, Ta and Ti is in a range of 0.8 times or more and 2 times or less of a total atomic content ratio of the C, N and O.   
     
     
         15 . The Cr based two-phase alloy according to  claim 2 , wherein
 an occupation ratio of the ferrite phase is 10% or more and 95% or less.   
     
     
         16 . The Cr based two-phase alloy according to  claim 14 , wherein
 an occupation ratio of the ferrite phase is 10% or more and 95% or less.   
     
     
         17 . The Cr based two-phase alloy according to  claim 6 , wherein
 the second optional accessory component consists of at least one of V, Nb, Ta and Ti, and   the total atomic content ratio of the V, Nb, Ta and Ti is in a range of 0.8 times or more and 2 times or less of the total atomic content ratio of the C, N and O.   
     
     
         18 . The Cr based two-phase alloy according to  claim 6 , wherein
 an occupation ratio of the ferrite phase is 10% or more and 95% or less.   
     
     
         19 . The Cr based two-phase alloy according to  claim 7 , wherein
 an occupation ratio of the ferrite phase is 10% or more and 95% or less.   
     
     
         20 . The Cr based two-phase alloy according to  claim 17 , wherein
 an occupation ratio of the ferrite phase is 10% or more and 95% or less.