Gas turbine disk material and heat treatment method therefor

Abstract

A gas turbine disk material according to the present invention contains: C: from 0.05 to 0.15%; Ni: from 0.25 to 1.50%; Cr: from 9.0 to 12.0%; Mo: from 0.50 to 0.90%; W: from 1.0 to 2.0%; V: from 0.10 to 0.30%; Nb: from 0.01 to 0.10%; Co: from 0.01 to 4.0%; B: from 0.0005 to 0.010%; N: from 0.01 to 0.05%; Mn: 0.40% or less; Si: 0.10% or less; and Al: 0.020% or less. A balance is of Fe and unavoidable impurities. Additionally, as a heat treatment method, a quenching temperature of a forged material having the component composition is set within a range from 1050 to 1150° C.

1 . A gas turbine disk material comprising, by mass %:
 C: from 0.05 to 0.15%;   Ni: from 0.25 to 1.50%;   Cr: from 9.0 to 12.0%;   Mo: from 0.50 to 0.90%;   W: from 1.0 to 2.0%;   V: from 0.10 to 0.30%;   Nb: from 0.01 to 0.10%;   Co: from 0.01 to 4.0%;   B: from 0.0005 to 0.010%;   N: from 0.01 to 0.05%;   Mn: 0.40% or less;   Si: 0.10% or less; and   Al: 0.020% or less, wherein   a balance is of Fe and unavoidable impurities.   
     
     
         2 . The gas turbine disk material according to  claim 1 , wherein
 a ratio of N content [N %] to Al content [Al %], [N %]/[Al %], is 2.4 or greater.   
     
     
         3 . The gas turbine disk material according to  claim 1 , wherein
 a B equivalent ([B %]+0.5 [N %]) expressed as a sum of content B [B %] and 0.5 times of content N [N %] is from 0.0055 to 0.030%.   
     
     
         4 . The gas turbine disk material according to  claim 1 , wherein
 an absorption energy in a room temperature Charpy impact test is 40 J or greater.   
     
     
         5 . The gas turbine disk material according to  claim 1 , wherein
 a creep rupture time at 596° C.×310 MPa is 750 hours or more.   
     
     
         6 . A heat treatment method for a gas turbine disk material, wherein
 when a heat treatment of heating and quenching a forged material having the component composition according to  claim 1  and then tempering the forged material is implemented, a quenching heating temperature is set within a range from 1050 to 1150° C.   
     
     
         7 . The gas turbine disk material according to  claim 1 , wherein
 a Ni content is 0.79 to 1.50% by mass.   
     
     
         8 . The gas turbine disk material according to  claim 1 , wherein
 a Cr content is 10.17 to 12.0% by mass.   
     
     
         9 . The gas turbine disk material according to  claim 1 , wherein
 a content of the unavoidable impurities is 0.015% or less by mass.