Ni-Cr-Mo ALLOY FOR WELDED TUBE HAVING SUPERIOR WORKABILITY AND CORROSION RESISTANCE

Abstract

A Ni—Cr—Mo alloy having superior workability and corrosion resistance of a welded part, the alloy consists of in mass %, C: 0.002 to 0.020%, Si: 0.02 to 1.00%, Mn: 0.02 to 1.00%, P: not more than 0.030%, S: not more than 0.005%, Cr: 18.0 to 24.0%, Mo: 7.5 to 9.0%, Cu: 0.01 to 0.20%, Al: 0.005 to 0.400%, Ti: 0.1 to 1.0%, Fe: 3.0 to 6.0%, Nb: 2.5 to 4.0%, Co: 0.01 to 0.50%, V: 0.05 to 0.50%, N: 0.002 to 0.020%, Sn: 0.003 to 0.030%, W: 0.05 to 0.50%, Nb+Ti+V: 2.5 to 4.5%, Cu+10Sn: not more than 0.40, and Ni and inevitable impurities as a remainder.

1 . A Ni—Cr—Mo alloy consisting of:
 in mass %, C: 0.002 to 0.020%, Si: 0.02 to 1.00%, Mn: 0.02 to 1.00%, P: not more than 0.030%, S: not more than 0.005%, Cr: 18.0 to 24.0%, Mo: 7.5 to 9.0%, Cu: 0.01 to 0.20%, Al: 0.005 to 0.400%, Ti: 0.1 to 1.0%, Fe: 3.0 to 6.0%, Nb: 2.5 to 4.0%, Co: 0.01 to 0.50%, V: 0.05 to 0.50%, N: 0.002 to 0.020%, Sn: 0.003 to 0.030%, W: 0.05 to 0.50%, Nb+Ti+V: 2.5 to 4.5%, Cu+10Sn: not more than 0.40, and Ni and inevitable impurities as a remainder. 
 
     
     
         2 . The Ni—Cr—Mo-alloy according to  claim 1 , wherein O: not more than 0.005%, Mg: 0.001 to 0.010%, and Ca: 0.0001 to 0.0100%.