| 摘要 |
PURPOSE:To obtain a highly corrosion resistant soft-magnetic bar and tube steel improved in corrosion resistance and specific resistance value without deteriorating electromagnetic properties, machinability, and hardness by specifying the composition consisting of C, N, Si, Mn, P, S, Cr, Mo, Al, Nb, and Fe. CONSTITUTION:This steel has a composition consisting of <=0.02% (C+N), <=2% Si, <=0.4% Mn, <=0.040% P, <=0.02% S, 16-21% Cr, 1-3% Mo, 1-3% Al, 0.2-0.5% Nb, and the balance essentially Fe. In this steel, respective contents of C and N are minimized and also C and N are fixed by the addition of Nb. As a result, electromagnetic properties as to have Hc<20e and B5>8.5kG are provided, and pitting corrosion resistance and corrosion resistance are improved and pitting corrosion potential is regulated to >= about 300mV, and further, superior machinability as to have <= about 25s drilling time is attained and also characteristics of >=85muOMEGA.cm specific resistance value and >= about HRB85 hardness are secured. By this method, the highly corrosion resistant soft- magnetic bar and tube steel increased in specific resistance value, having superior corrosion resistance combined with pitting corrosion resistance, and also excellent in electromagnetic properties and machinability can be obtained. |
