Properties of duplex treated (gas-nitriding and PVD-TiN, -Cr2N) low alloy steel

Materials Today: Proceedings

Trinadh

2019

The present concerns surface modification of low alloy CrMoV steel by following the route of plasma nitriding for the improvement of hardness. Plasma nitriding was performed at a low temperature of 450 o C. The maximum hardness at this lower temperature was found to be ~1270 Hv after nitriding. At 550 o C though the hardness improvement near the surface region was similar but the core hardness was reduced. XRD studies revealed various nitrides of iron (γ′ (Fe 4 N) and ε (Fe 2-3 N)) with the ε nitride as the dominant phase. SEM analyses revealed the surface microstructure with almost no white layer. EDS point analyses shown the signature of N on the surface layer. It has been concluded in this study that the hardness of 90CrMoV8 steel can be improved significantly even at a low temperature of 450 o C without any of risk of the loss of core hardness.

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Low Temperature Plasma Nitriding of Low Alloy Steel for the Enhancement of Hardness

Materials Today: Proceedings

Trinadh

2019

“…Plasma nitriding is one of most promising surface modification methods, which has gained popularity than others. The modified surface does not face any interfacial adhesion problem as found at the interface of the layer deposited by PVD/CVD methods [3,4]. Efficiency, eco-friendliness, process controllability and cost effectiveness have made plasma nitriding an attractive and popular method for the surface modification of materials like steel, titanium, ceramics for the improvement of properties e.g.…”

Section: Introductionmentioning

confidence: 99%

Effects of low and high temperature plasma nitriding on electrochemical corrosion of steel

Materials Today: Proceedings

Lakshman

et al. 2021

This study concerns plasma nitriding of tool steel at different temperatures and its effects on corrosion resistance. Inside the nitriding reactor steel samples were placed on the sample holder after metallographic polishing and then the vacuum chamber was evacuated to a pressure of $0.5 Pa. At a lower temperature of 450°C and the higher temperature of 550°C nitriding was performed for a fixed duration of 10 h.All the nitrided and the bare steel samples studied under X-ray diffraction (XRD) and scanning electron microscopic analysis/energy dispersive X-ray spectroscopy (EDS). Iron nitride (Fe x N, x = 2-3, 4) peaks were revealed in the nitrided steels after XRD analyses. EDS revealed the increased amount of nitrogen in the nitrided sample treated at 550 °C. For the assessment of corrosion resistance of these steel samples potentiodynamic polarization tests were performed in 3.5% NaCl. On comparison, it was found that the steel nitrided at higher temperature is more effective in enhancing the corrosion resistance.

“…by following physical or chemical vapour deposition, on the surface of the steel can solve this problem but the poor adhesion and the delamination of the deposited layer limits its applications [1,2]. In this regard, nitriding has already been proved to be a successful method to improve these properties without the problem of delamination of the deposited layers [3,4]. Conventional ammonia nitriding has problems related to controllability of process parameters and side effects to the environment.…”

Section: Introductionmentioning

confidence: 99%

Low-temperature plasma nitriding of martensitic stainless steel

Trinadh

2020

Trans Indian Inst Met

This study presents the plasma nitriding of Cr-Mo-V tool steel to protect it from environmental degradation. The steel samples after metallographic polishing were nitrided in the glow discharge plasma of N 2 and H 2 gas mixture (80:20). Nitriding was performed at two different temperatures, a lower temperature of 450°C and the higher temperature of 500°C. The potentiodynamic polarization tests in 3.5% NaCl electrolyte had shown the enhancement of corrosion resistance of steels after nitriding. X-ray diffraction (XRD) studies and scanning electron microscopic analysis coupled with energy dispersive spectroscopic analysis (SEM/EDS) was performed to understand the modification of surface microstructure. XRD analysis of the nitrided steels revealed the presence of c 0 -and e-nitrides of iron, which were responsible for the improvement of corrosion resistance.