Ion Nitriding

Abstract

The ion nitriding has many advantages for the gas nitriding or the salt-bath method. To obtain nessesary data to scale-up the ion nitriding to an industrial scale is purposed. (1) A suitable pumping system for the ion nitriding is a combination of a mechanical booster and a rotary pump. (2) Mixed gas of nitrogen and hydrogen with the ratio of 2 to 1 is suitable for the treating gas. (3) Gamma-dash phases are usually observed and epsilon phases are not appeared in the experimental range of 0.05 to 2 Torr for S45G, SACM-1 and eutectic cast iron F2 even though the thicknesses of the layers are different for each materials. (4) Temperature which the nitriding effect becomes evident is approximately 300°C for laboratorious and industrial scale of time. (5) Activation energies of ion nitriding are 14.7, 16.2, 17.3, and 22.4 for SACM-1, S45C, SUS304 and F2, respectively, which are farely lower than them of gas nitriding. (6) Size changes due to the ion nitriding at 500°C, 10 hours are within 2, 3, 5, and 12 microns increase for S45C, SACM-1, F2 and SUS304, respectively, which are nearly same as them reported for gas nitriding. © 1974, The Vacuum Society of Japan. All rights reserved.