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.

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 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

The Kinetics of Gas Nitrided Layer Growth on Austenitic Stainless Steel

2010 ◽  
Vol 297-301 ◽  
pp. 573-578 ◽  
Author(s):  
Jolanta Baranowska
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Nitrided Layer ◽  
Light And Electron Microscopy ◽  
Layer Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treated Steel ◽  
Optical Spectrometry ◽  
Kinetics Of

This paper presents the results of investigations on gas nitrided austenitic stainless steel. The treatment was conducted at various temperatures (400-515°C), gas compositions of atmospheres used (20-100% NH3) and times (0.5-12h). The layers were investigated by X-ray diffraction, Light and Electron Microscopy and Glow Discharge Optical Spectrometry. The kinetics of layer growth has been analysed in terms of the process parameters and compared with the data presented for plasma treated steel. The specific nitrogen profiles of nitrided layers are discussed in the context of the layers’ microstructure and phase composition.

New possibilities for controlling gas nitriding process by simulation of growth kinetics of nitride layers

1999 ◽  
Vol 15 (5) ◽  
pp. 377-384 ◽  
Author(s):  
L. Maldzinski ◽  
W. Liliental ◽  
G. Tymowski ◽  
J. Tacikowski
Keyword(s):  
Growth Kinetics ◽  
Nitriding Process ◽  
Gas Nitriding ◽  
Nitride Layers ◽  
Kinetics Of

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 Effects of Modifying the Activity of Nitriding Media by Diluting Ammonia with Nitrogen

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2432
Author(s):  
Mihai Ovidiu Cojocaru ◽  
Mihai Branzei ◽  
Andrei Mihai Ghinea ◽  
Leontin Nicolae Druga
Keyword(s):  
Growth Kinetics ◽  
Nitrided Layer ◽  
Gaseous Mixture ◽  
Ammonia Nitrogen ◽  
Layer Growth ◽  
Gaseous Ammonia ◽  
Kinetics Parameters ◽  
Nitrogen Dilution ◽  
Nitrogen Mixture ◽  
Kinetics Of

This paper discusses the issue of the effects of modifying the activity of nitriding media by diluting ammonia with nitrogen and the concomitant variation in the degree of ammonia dissociation on the layer’s growth kinetics and their phase composition. To understand and quantify the effects of the variation in the main parameters that influence the layer growth kinetics, the experimental programming method was used and mathematical models of interactions between influence and kinetics parameters were obtained for two metallic materials: Fe-ARMCO and 34CrAlMo5 nitralloy steel. It was concluded that the nitriding operating temperature and the degree of nitrogen dilution of the ammonia have statistically significant influences on the kinetics of the nitrided layer. In the same context, it was analytically proved and experimentally confirmed that the ammonia degree dissociation from the gaseous ammonia-nitrogen mixture, along with the dilution degree of the medium with nitrogen, significantly influences the nitrogen potential of the gaseous mixture used for nitriding and thus the concentration of nitrogen in balance at the medium thermochemically processed metal product interface.

White Layer Control in Gas Nitriding Process Using an Oxygen Sensor

2012 ◽  
Vol 579 ◽  
pp. 278-286 ◽  
Author(s):  
Han Ming Chen ◽  
Yu Chi Lin ◽  
Yong Chwang Chen
Keyword(s):  
Flow Rate ◽  
Output Voltage ◽  
Oxygen Sensor ◽  
White Layer ◽  
Experimental Results ◽  
Nitriding Process ◽  
Hardness Distribution ◽  
Gas Nitriding ◽  
Layer Control

There are many advantages in nitriding process, but the formation of white layer sometimes results in trouble. The formation of white layer can be reduced by controlling the nitriding atmosphere appropriately. In this experiment, the nitriding atmosphere is prepared by mixing NH3 and H2. An oxygen sensor is used to detect the condition of the atmosphere, and the value of output voltage (EMF) is used as a signal for controlling the flow rate of H2. The experimental results show that the thickness of white layer can be reduced effectively by controlling the flow rate of H2 through the voltage reading of the atmosphere. Meanwhile, the hardness and the depth of nitriding layer could still be maintained. For nitriding at 550 °C, no white layer is formed when EMF is controlled above 1160 mV and a satisfying hardness distribution of the nitriding layer can be obtained when EMF is controlled at 1140 mV.

scholarly journals INFLUENCE OF PRE-OXIDATION ON THE NITRIDING PROCESS OF IRON ALLOYS

2021 ◽  
Vol 2 (55) ◽  
pp. 54-59
Author(s):  
V.F. Gahramanov ◽  
◽  
E.A. Aslanov ◽  
Keyword(s):  
Solid Solution ◽  
Carbide Phase ◽  
High Speed ◽  
Nitrided Layer ◽  
High Hardness ◽  
Iron Alloys ◽  
Nitriding Process ◽  
Tempering Temperature ◽  
Significant Difference ◽  
Kinetics Of

The article presents the results of studying the kinetics of oxidation of Fe-Cr, Fe-Al and iron alloys at temperatures of 450–550 °C. The influence of preliminary oxidation of these alloys on the nitriding process has been studied. It has been established that alloying of Fe-Cr, Fe-Al alloys increases the amount of absorbed nitrogen, but decreases the overall depth of the nitrided layer. The duration of nitriding required to develop high hardness (over HV 1,000) depends on the composition of the solid solution. At a nitriding temperature of 520 °C, exposure is 10–15 minutes for steels of the first group, at least 3–4 h for steels of the second and third groups, and 5–6 h for steels of the fourth group. Studies have shown that the hardness of the layer is determined mainly by the composition of the solid solution; the amount and dispersion of the carbide phase have less effect. The hardness increases as a result of an increase in the hardening temperature and a decrease in the tempering temperature, which reduce the amount of the carbide phase, but increase the alloying of the solid solution. The hardness of the nitrided layer of high-speed steels P9, P18, having the same composition of the solid solution, is the same (HV 1,340) even despite the significant difference in the amount of the carbide phase. The hardness of the layer of steel 4Х5В2ФС (4Kh5V2FS), which contains more chromium in the solution, is HV 50–90 higher than the hardness of the layer on the steel 3Х2В8Ф (3Kh2V8F), which has 1.5–2 times more of the carbide phase. The behavior of steels with the same high chromium content (12 %), but different carbon content is characteristic. The hardness of the layer in steel 1Х13 (1Kh13), which has few carbides, is HV 100–180 higher than the hardness of the layer in steel Х12М (Kh12M), in which a significant portion of chromium is bound into carbides.

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