Effects of Nickel Screen on Active Screen Plasma Nitriding

Abstract

Active screen plasma nitriding (ASPN) is a nitriding method that avoids the edge effects and arcing that occur during conventional direct current plasma nitriding (DCPN). Furthermore, applying voltage to a sample during ASPN allows the nitriding rate to be increased (S-DCPN). While steel is the predominant screen material, there are few reports of non-ferrous material screens. Therefore, in this study, we investigated the effect of a Ni screen on ASPN and S-DCPN. Low carbon steel S15C was treated by ASPN and S-DCPN using a Ni screen. A steel plate cold commercial (SPCC) screen was also prepared for comparison. Plasma nitriding was performed at 773 K for 240 min under an atmosphere of 75% N 2 + 25% H 2 at a gas pressure of 200 Pa. After the nitriding treatment, X-ray diffraction (XRD), glow discharge optical emission spectrometry (GD-OES), cross-sectional microstructure observation, surface microstructure observation, Vickers hardness test, and corrosion test were performed. As a result, when the Ni screen was used for S15C steel nitriding, more nitrogen atoms diffused into the sample than that when the SPCC screen was used; furthermore, nickel atoms diffused within the samples treated by both ASPN and S-DCPN using the Ni screen. ASPN-treated samples had less surface hardness and were higher corrosion resistance when prepared using the Ni screen than the SPCC screen. S-DCPN-treated samples had greater surface hardness and were less corrosion resistance when prepared using the Ni screen than the SPCC screen.

Influence of Time and Temperature of Plasma Nitriding on the Wear Resistance of Ni–Cr–Mo‐Based Films Deposited by AISI 904L Cathodic Cage on SAE 6160 Steel

“…[ 17,40,47–50 ] For sample D 450 , which went through the cathodic cage deposition process, the presence of FeN and Fe 2 N phases from the nitriding kinetics is verified because the deposition is carried out with an AISI 904L steel cage and in a nitriding atmosphere. [ 5,45,51 ] It is possible to verify a slight displacement of the peaks related to Fe‐α due to the decarburization of AISI 6160 and, consequently, the appearance of voids in the crystalline structure of the ferrite; [ 52 ] this decarburization, as suggested by previous studies, [ 1,53 ] can generate the formation of FeN and Fe–Cr. The presence of phases from the material of the cathodic cage can still be observed, such as Ni 3 Mo 3 N peaks, which is expected due to the high content of nickel present in the AISI 904L steel and the molybdenum present in the SAE 6160 and AISI 904L steels.…”

Surface modification of AISI-420 steel by cathodic cage plasma niobium nitride deposition

“…Niobium nitride coating by this technique is expected to provide exceptional surface properties and better adhesion with the substrate. 22,23 CCPD is widely reported to deposit numerous coatings, such as copper, 24 silver, 25 zinc, 26 aluminium, 27 titanium, 28 nickel, 29 and Hastelloy. 30 Previously, 31 this system was used for synthesising molybdenum oxide and zinc oxide coating on steel, with excellent mechanical and tribological performance.…”