Lean duplex stainless steel excellent in corrosion resistance and hot workability

摘要

The present invention desalination plants, pulp and paper industry equipment, chemical equipment, construction equipment A low-alloy duplex stainless steel used in industrial plants, including, in weight%, C: 0 or less than 0.06%, Si: 0 or less than 1.5%, Mn: 0 or less than 1.8%, Cr: 19 ~ 23%, Ni: 1.8 ~ 3.5%, Mo 0.5 ~ 1.0%, Cu: 0.3 ~ 1.0%, N: 0.16 ~ 0.30%, Al: 0.003 ~ 0.05%, B: 0.001 ~ 0.005%, Ca: from 0.001 to 0.01% comprising the , the content of the stainless steel, carbon steel O is limited to not more than 0.01%, and the remainder including Fe and inevitable impurities, the sum of B and Ca is 0.0035 to 0.006% in weight percent, the composition of the stainless steel (1 ), and Creq value obtained from the formula is 22.5 to 23.5, to (2) the value of Nieq by formula is 9.5 to 11, and the hot workability index is calculated by the following equation (3) more than 75, the hot workability index The minimum temperature in stainless steel with excellent corrosion resistance and hot workability of the cross-sectional area reduction rate of the low-alloyed duplex stainless steel is provided. [Cr] + [Mo] + 1.5 [Si] --- (1) [Ni] + 30 ([C] + [N]) + 0.5 ([Mn] + [Cu]) --- (2) -195 + 10.2 Creq + 1.19 Nieq + 822 [Al] + 1297 (B + Ca) --- (3) ;