scholarly journals Effective Duration of Gas Nitriding Process on AISI 316L for the Formation of a Desired Thickness of Surface Nitrided Layer

2014 ◽  
Vol 13 ◽  
pp. 04021
Author(s):  
Hassan R. S. Mahmoud ◽  
Syafiq A. Yusoff ◽  
Azman Zainuddin ◽  
Patthi Hussain ◽  
Mokhtar Ismail ◽  
...  
Keyword(s):  
Nitrided Layer ◽  
Nitriding Process ◽  
Aisi 316L ◽  
Gas Nitriding

scholarly journals The influence of laser re-melting on microstructure and hardness of gas-nitrided steel

2016 ◽  
Vol 36 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Dominika Panfil ◽  
Piotr Wach ◽  
Michał Kulka ◽  
Jerzy Michalski
Keyword(s):  
Laser Beam ◽  
Laser Treatment ◽  
Diffusion Zone ◽  
Nitrided Layer ◽  
Nitriding Process ◽  
Beam Power ◽  
Gas Nitriding ◽  
Nitrided Steel ◽  
Laser Beam Power ◽  
And Diffusion

Abstract In this paper, modification of nitrided layer by laser re-melting was presented. The nitriding process has many advantageous properties. Controlled gas nitriding was carried out on 42CrMo4 steel. As a consequence of this process, ε+γ’ compound zone and diffusion zone were produced at the surface. Next, the nitrided layer was laser remelted using TRUMPF TLF 2600 Turbo CO2 laser. Laser tracks were arranged as single tracks with the use of various laser beam powers (P), ranging from 0.39 to 1.04 kW. The effects of laser beam power on the microstructure, dimensions of laser tracks and hardness profiles were analyzed. Laser treatment caused the decomposition of continuous compound zone at the surface and an increase in hardness of previously nitrided layer because of the appearance of martensite in re-melted and heat-affected zones

Kinetics of nitrided layers formation on low-alloy steels in the gas nitriding process

2020 ◽  
Vol 24 (4) ◽  
pp. 31-36
Author(s):  
Grzegorz Wójcik ◽  
Barbara Kucharska ◽  
Piotr Wach
Keyword(s):  
Diffusion Layer ◽  
Nitrided Layer ◽  
Surface Hardness ◽  
Nitriding Process ◽  
Process Time ◽  
Low Alloy Steels ◽  
Two Phase ◽  
Gas Nitriding ◽  
Alloy Steels ◽  
Kinetics Of

The study examined cylindrical samples made of low-alloy structural steel 42CrMo4 (40HM) and 41CrAlMo7 (38HMJ) subjected to the nitriding process at 540oC during 2, 7, 12 and 17 hours. During the first 2 hours of the process, the atmosphere was ammonia, while the rest of the process was carried out in the atmosphere consisting of 50% ammonia and 50% dissociated ammonia. After the process, surface hardness, hardness distribution at the depth of 50 µm from the surface up to the hardness of the core, and microstructure of the nitrided layer produced were examined. It has been shown that along with the extension of the duration of the nitriding process on 40HM steel, the surface thickness of the layer of nitrides increases from 6 µm after 2 hours to 14 µm after 17 hours of the process and this layer has a two-phase structure (+’), while the thickness of the diffusion layer was from 0.15 to 0.44 mm (depending on the process time). In the case of 38HMJ steel, the thickness of the layer of nitrides increased from 1 µm after 2 hours to 9.5 µm after 17 hours. The thickness of the diffusion layer was from 0.08 to 0.35 µm (depending on the process time).

scholarly journals Nitriding of car engine parts using ZeroFlow method

2016 ◽  
Vol 167 (4) ◽  
pp. 3-7
Author(s):  
Jagoda KOWALSKA ◽  
Leszek MAŁDZIŃSKI
Keyword(s):  
Nitrided Layer ◽  
Simulation Models ◽  
Layer Growth ◽  
Nitriding Process ◽  
Hardness Distribution ◽  
Practical Application ◽  
Influence Of Process Parameters ◽  
Gas Nitriding ◽  
And Control ◽  
Kinetics Of

This article presents new method of controlled gas nitriding called ZeroFlow, which is used for nitriding of selected car engine parts. Parts such as crankshafts, camshafts, piston rings, poppet valve springs and discs, piston pins or nozzles for unit injectors was nitrided with ZeroFlow method so far. Through the use of simulation models it was possible to develop the specially dedicated process with specific parameters for each of this parts; it allows forming of nitrided layer with strictly expected properties: required phase structure with thicknesses of each zone occurs in it and required hardness distribution. Moreover, through the use of simulation models this layers were obtained in in the shortest possible time, which is connected with the lowest energy consumption; therefore, nitriding process using ZeroFlow method is both economical and environmentally friendly. This article will discuss the essence of controlled gas nitriding process, with an emphasis on the influence of process parameters on results of nitriding process. This information are the basis to understand the issue of the kinetics of nitrided layer growth, and as it follows – for its practical application in designing, regulation and control of nitriding processes using simulation models (simulator of the kinetics of nitrided layer growth). Designing of ZeroFlow nitriding processes on the basis of the kinetics of nitrided layer will be shown on the example of nitriding of crankshafts for sports car engines.

White Layer Control on AISI 316L Using Temperature and Gas Nitriding Diffusion Stage Process

2017 ◽  
Vol 11 (8) ◽  
pp. 613
Author(s):  
Komang Astana Widi ◽  
Wardana Wardana ◽  
Wahyono Suprapto ◽  
Yudy Surya Irawan
Keyword(s):  
White Layer ◽  
Aisi 316L ◽  
Gas Nitriding ◽  
Diffusion Stage ◽  
Stage Process ◽  
Layer Control

Mechanical Behaviour of Gas Nitrided Ti6Al4V Bars Produced by Selective Laser Melting

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Nitrided Layer ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Processing Parameters ◽  
Heat Treatments ◽  
Laser Melting ◽  
Gas Nitriding ◽  
Heat Treated

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.

scholarly journals Effect of Adjusted Gas Nitriding Parameters on Microstructure and Wear Resistance of HVOF-Sprayed AISI 316L Coatings

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1760 ◽  
Author(s):  
Pia Kutschmann ◽  
Thomas Lindner ◽  
Kristian Börner ◽  
Ulrich Reese ◽  
Thomas Lampke
Keyword(s):  
Wear Resistance ◽  
Low Temperature ◽  
Process Management ◽  
Surface Activation ◽  
Aisi 316L ◽  
Spray Coatings ◽  
Gas Nitriding ◽  
Surface Distance ◽  
Diffusion Depth ◽  
Sprayed Coating

Gas nitriding is known as a convenient process to improve the wear resistance of steel components. A precipitation-free hardening by low-temperature processes is established to retain the good corrosion resistance of stainless steel. In cases of thermal spray coatings, the interstitial solvation is achieved without an additional surface activation step. The open porosity permits the penetration of the donator media and leads to a structural diffusion. An inhomogeneous diffusion enrichment occurs at the single spray particle edges within the coating’s microstructure. A decreasing diffusion depth is found with increasing surface distance. The present study investigates an adjusted process management for low-temperature gas nitriding of high velocity oxy-fuel-sprayed AISI 316L coatings. To maintain a homogeneous diffusion depth within the coating, a pressure modulation during the process is studied. Additionally, the use of cracked gas as donator is examined. The process management is designed without an additional surface activation step. Regardless of surface distance, microstructural investigations reveal a homogeneous diffusion depth by a reduced processing time. The constant hardening depth allows a reliable prediction of the coatings’ properties. An enhanced hardness and improved wear resistance is found in comparison with the as-sprayed coating condition.

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