Studies on low-energy nitrogen plasma immersion ion implantation on austenitic stainless steel and Cu-strengthened HSLA-100 steel

Low-energy (∼1 keV) nitrogen plasma immersion ion implantation was used to modify austenitic stainless steel and Cu-strengthened HSLA-100 steel. The variable implantation parameters were treatment time, gas composition and treatment temperature. For austenitic stainless steels, it was found that the expanded austenite phase formed by low-temperature implantation, did not always prove to be corrosion resistant, though there was an increase in the hardness. For Cu-strengthened HSLA-100 steel, an enhancement in the linear strain to failure under embrittling conditions was observed, which was due to introduction of residual compressive stresses as well as reduction in the hydrogen flux. The results emphasize the use of low energy in Plasma Immersion Ion Implantation (PIII) and its applicability to solving different surface engineering problems.