DUPLEX STAINLESS STEEL WIRE MATERIAL, STEEL WIRE, BOLT, AND METHOD FOR PRODUCTION OF THE BOLT

摘要

Disclosed is an austenite-ferrite duplex steel wire material for a high-strength, high-corrosion-resistant bolt, which has excellent cold forgeability. The steel wire material comprises the following components (by mass): C: 0.005-0.05%, Si: 0.1-1.0%, Mn: 0.1-10.0%, Ni: 1.0-6.0%, Cr: 19.0-30.0%, Cu: 0.05-3.0% and N: 0.005-0.20%, with the remainder being Fe and substantially unavoidable impurities, wherein the total content of C and N is 0.20% or less, the M value represented by the formula (a) below is 60 or less, the F value represented by the formula (b) is 45 to 85, and the tensile strength is 550 to 750 N/mm2. M = 551-462(C+N)-9.2Si-8.1Mn-29(Ni+Cu)-13.7Cr-18.5Mo (a) F = 5.6Cr-7.1Ni+2.4Mo+15Si-3.1Mn-300C-134N-26.6 (b)