Austenitic heat-resistant nickel-base alloy

Abstract

Austentic heat-resistant nickel-base alloy comprising (in % by mass) 0.03-0.1% of C, 28-32% of Cr, 0.01-<0.5% of Mn, 0.01-<0.3% of Si, 0.01-<1.0% of Mo, 2.5-3.2% of Ti, 0.01-<0.5% of Nb, 0.01-<0.5% of Cu, 0.05-<2.0% of Fe, 0.7-1.0% of Al, 0.001-<0.03% of Mg, 0.01-<1.0% of Co, 0.01-0.10% of Hf, 0.01-0.10% of Zr, 0.002-0.02% of B, 0.001-0.01% of N, max. 0.01% of 5, max. 0.005% of Pb, max. 0.0005% of Bi, max. 0.01% of Ag, balance Ni and minor components due to the production method, where the sum of Ti +Al is from 3.3 to 4.3%, the sum of C+(10×B) is from 0.05 to 0.2%, the sum of Hf+Zr is from 0.05 to 0.15%, the Ti/Al ratio is >3 and Zr/Hf is 0.1 to 0.5.

1 . Austenitic heat-resistant nickel-based alloy having (in mass %):
 0.03-0.1% C   28-32% Cr   0.01-≦0.5% Mn   0.01-≦0.3% Si   0.01-≦1.0% Mo   2.5-3.2% Ti   0.01-≦0.5% Nb   0.01-≦0.5% Cu   0.05-≦2.0% Fe   0.7-1.0% Al   0.001-≦0.03% Mg   0.01-≦1.0% Co   0.01-0.10% Hf   0.01-0.10% Zr   0.002-0.02% B   0.01-0.01% N   max. 0.01% S   max. 0.005% Pb   max. 0.0005% Bi   max. 0.01% Ag   remainder Ni and process-related impurities,   the sum of Ti+Al being between 3.3 and 4.3%,   the sum of C+(10×B) being between 0.05 and 0.2%,   the sum of Hf+Zr being between 0.05 and 0.15%,   and Ti/Al being >3.   
     
     
         2 . Alloy in accordance with  claim 1  that includes (in mass %) 28-31% Cr. 
     
     
         3 . Alloy in accordance with  claim 1  or  2  that includes (in mass %) 29-31% Cr. 
     
     
         4 . Alloy in accordance with  claims 1  through  3 , that includes (in mass %) 2.8 3.2% Ti. 
     
     
         5 . Alloy in accordance with  claims 1  through  4  that includes (in mass %) 2.8-3.0% Ti. 
     
     
         6 . Alloy in accordance with  claims 1  through  5  that includes boron as an additive (in mass %) 0.002-0.01%, in particular 0.002-0.005%. 
     
     
         7 . Alloy in accordance with  claims 1  through  6  in which the sum of C+(10×B) is 0.05 to 0.1%, and in particular is between 0.05-0.08%. 
     
     
         8 . Alloy in accordance with  claims 1  through  7  in which the Zr content is set between 0.01 to 0.05%. 
     
     
         9 . Alloy in accordance with  claims 1  through  8  in which the Hf content is set between 0.01 to 0.08%. 
     
     
         10 . Alloy in accordance with any of  claims 1  through  9  in which the following relationship is true:
   Zr/Hf=0.1-0.5%   
     
     
         11 . Alloy in accordance with any of  claims 1  through  10 , characterized in that Ti/Al is between 3.3 and 4.2. 
     
     
         12 . Use of the alloy in accordance with any of  claims 1  through  11  as a valve material, in particular for valves that can be used in diesel engines. 
     
     
         13 . Use of the alloy in accordance with any of  claims 1  through  11  as a valve material for valves that can be used in diesel engines on ships in the temperature range up to 850° C. 
     
     
         14 . Valve, in particular for a large diesel engine, that at least partially comprises an alloy in accordance with any of  claims 1  through  11 .