| 摘要 |
PURPOSE:To produce easily a wire for a dot printer having excellent toughness and wear resistance by subjecting a steel consisting of C, si, Mn, Ni, Mo, Co, Al, Ti and iron to a soln. heat treatment, cold drawing and nitriding treatment. CONSTITUTION:A rolled coil of the steel consisting of <=0.03wt% C, <=0.10% Si, <=0.10% Mn, 17.0-19.0% Ni, 3.0-6.0% Mo, 7.0-10.0% Co, 0.05-0.20% Al, 0.10-0.90% Ti, and the balance iron and impurities is air cooled from about 820 deg.C and is subjected to a soln. heat treatment. The steel which is made relatively low in hardness to about 28-32 HRC by such treatment is subjected repeatedly to the stage for cold drawing down to about 95% reduction of area to form a wire having about 0.3mm. diameter. The wire is subjected to a gas nitriding or gas soft nitriding treatment for several hours at about 480 deg.C to form the surface hardened layer having >=800HV and 0.005-0.020mm. thickness and at the same time the central part of the wire is age-hardened. The titled wire having excellent toughness and wear resistance is thus obtd. |
