Corrosion resistance of surface treated 42CrMo4 steel

Abstract

This article deals with corrosion resistance comparison of plasma nitrided 42CrMo4 steel to another surface technologies used for breech mechanism manufacturing in the armament production. Increasing of demands on materials used for armament production and in other industrial applications leads to the innovation of technologies in the field of surface treatment, especially wear resistance, surface hardness, running-in properties and corrosion resistance, optical demands and others. For the evaluation of experimental corrosion resistance were plasma nitrided samples of 42CrMo4 steel compared with alkali blackening, manganese phosphate and Arcor technologies. The conditions of plasma nitriding process were set to provide exactly defined nitride layers with defined parameters. In this case, the above-mentioned surface technologies were applied to individual samples of 42CrMo4 steel, which were subsequently metallographically evaluated and the hardness and microhardness were measured. The corrosion resistance comparison was realized by the NSS corrosion tests in the condensation chamber and visually evaluated. The results and comparison of corrosion resistance of plasma nitrided steel samples with above-mentioned surface treatment technologies showed significant differences in corrosion rate propagation. Thank to different plasma nitriding conditions, there are evident differences in corrosion resistance between the plasma nitrided steel samples as well. The corrosion resistance evaluation is supplemented by the surface layer characteristics. K e y w o r d s : plasma nitriding, breech mechanism, corrosion resistance

wear resistance enhancement of Case-hardening steels by utilizing plasma nitriding in military applications

“…After 15 hours of plasma nitriding in the nitriding appliance the white layer with thickness oscillating around 4 µm covered the specimen´s surface. A significant porosity was not visible in the compound layer, hence the compound layer can also provide an enhancement of the surface´s corrosion resistance [17,18].…”

Creation of wear-resistant layers on steels using TIG electric arc surface remelting process with applying CaCN2-based nitriding powder

“…Li et al [13] found that in plasma nitriding of austenitic steel, the hardness achieved depends on the nitriding time. Nitrided layers are resistant to fatigue and wear and have good sliding properties and corrosion resistance [11,14].…”

Corrosion Resistance of Plasma Nitriding and Zinc Phosphating Duplex System for C45 Steel

“…And new nitriding technologies are continuously developed e. g active screen plasma nitriding (ASPN) to increase the effectivity of plasma nitriding, but not widely used in industry application (5). The plasma nitriding process is applied to ferrous materials (for all grades of steel, cast irons) has been extensively used to improve the surface properties (6), fatigue (7), corrosion (8), and also improve load-bearing capacity of dynamically loaded components friction and wear properties (9). However, it should be noted that some properties such as notch toughness may be reduced (10).…”