Fe-Cr-Ni-Mo ALLOY AND METHOD FOR PRODUCING THE SAME

摘要

Fe—Cr—Ni—Mo alloy having superior surface properties and a method for producing the same using a commonly used apparatus at low cost. The Fe—Cr—Ni—Mo alloy has (% indicates mass %): C: ≦0.03%, Si: 0.15 to 0.5%, Mn: 0.1 to 1%, P: ≦0.03%, S: ≦0.002%, Ni: 20 to 32%, Cr: 20 to 26%, Mo: 0.5 to 2.5%, Al: 0.1 to 0.5%, Ti: 0.1 to 0.5%, Mg: 0.0002 to 0.01%, Ca: 0.0002 to 0.01%, N: ≦0.02%, O: 0.0001 to 0.01%, freely contained components of Co: 0.05 to 2% and Cu: 0.01 to 0.5%, Fe as a remainder, and inevitable impurities, wherein MgO, MgO.Al2O3 spinel type, and CaO—Al2O3—MgO type are contained as oxide type non-metallic inclusions, ratio of number of MgO.Al2O3 spinel type to all oxide type non-metallic inclusions is ≦50%, and CaO—Al2O3—MgO type contains CaO: 30 to 70%, Al2O3: 5 to 60%, MgO: 1 to 30%, SiO2: ≦8%, and TiO2: ≦10%.

主权项

1. An Fe—Cr—Ni—Mo alloy comprising, % indicating mass %:
C: 0.03% or less, Si: 0.15 to 0.5%, Mn: 0.1 to 1%, P: 0.03% or less, S: 0.002% or less, Ni: 20 to 32%, Cr: 20 to 26%, Mo: 0.5 to 2.5%, Al: 0.1 to 0.5%, Ti: 0.1 to 0.5%, Mg: 0.0002 to 0.01%, Ca: 0.0002 to 0.01%, N: 0.02% or less, O: 0.0001 to 0.01%, Co: 0.05 to 2% and Cu: 0.01 to 0.5% as freely contained components, Fe as a remainder, and inevitable impurities, wherein MgO, MgO.Al2O3 spinel type, and CaO—Al2O3—MgO type are contained as oxide type non-metallic inclusions, ratio of number of the MgO.Al2O3 spinel type to all oxide type non-metallic inclusions is 50% or less, and the CaO—Al2O3—MgO type comprises CaO: 30 to 70%, Al2O3: 5 to 60%, MgO: 1 to 30%, SiO2: 8% or less, and TiO2: 10% or less.