scholarly journals Kinetics of Austenite Layer Growth on the Surface of Fe-23Cr-2.4Mo Ferritic Stainless Steel During Solution Nitriding

2017 ◽  
Vol 36 (2) ◽  
pp. 55-66 ◽  
Author(s):  
Kh. Farjam Hajiagha ◽  
A. R. Akbari ◽  
R. Mohammadzadeh ◽  
◽  
◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Layer Growth ◽  
Kinetics Of

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.

scholarly journals HIGH TEMPERATURE OXIDATION OF AISI 439 FERRITIC STAINLESS STEEL IN SYNTHETIC AIR ATMOSPHERE

2018 ◽  
Vol 80 (5) ◽  
Author(s):  
Maria de Fatima Salgado ◽  
Jackeline Macêdo de Sousa Santos ◽  
Giscard Eanes Dias Viana ◽  
João Alberto Santos Porto ◽  
Gabriel de Souza Veras Fontinele ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Oxidation Kinetics ◽  
Principal Element ◽  
Oxidation Treatment ◽  
Temperature Oxidation ◽  
X Ray ◽  
Air Atmosphere ◽  
Steel Oxidation ◽  
Kinetics Of

Stainless steels may be used and exposed to aggressive gases at high temperatures. The oxidation behavior of AISI 439 ferritic stainless steel, was investigated by oxidation treatment at 850 ºC and 950 ºC, for 50h in Synthetic Air with 20% O2 atmosphere in a tubular oven and in a thermobalance. The oxidation kinetics of films are determined by measuring the mass versus oxidation time. The microstructure and chemical composition of the oxides were determined by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS).  Chemical analysis by EDS showed that films formed on AISI 439 stainless steel exhibited Cr as the principal element in the oxide film, in proportions to form the chromium oxide (Cr2O3) and the following elements: Mn, Fe, Ti and Si. Based on the oxidation kinetics, it was observed that steel oxidation follows the parabolic behaviour with increase in temperature and it produced the highest oxidation rate at 950 ºC and the lowest rate at 850 ºC. 

Simulation of Line Annealing of Type 430 Ferritic Stainless Steel

2012 ◽  
Vol 715-716 ◽  
pp. 437-446
Author(s):  
Anna P. Kisko ◽  
Pasi P. Suikkanen ◽  
C. Isaac Garcia ◽  
K. Cho ◽  
M. Hua ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Fiber Orientation ◽  
Experimental Conditions ◽  
Metallographic Examination ◽  
Annealing Behavior ◽  
The Subject ◽  
Cold Rolled ◽  
Cold Worked ◽  
Kinetics Of

The annealing behavior of cold rolled Type 430 ferritic stainless steel is the subject of this paper. The steel was cold rolled 79%, then heated at 6 °C/s to the soaking temperature of 841 °C, which is just below the Ae1temperature. During heating, specimens were quenched from selected temperatures between 650 and 841 °C and after various times at 841 °C. These quenched samples underwent metallographic examination and micro-hardness determination. The results indicated that under the prevailing experimental conditions, the hardness appeared to correlate strongly with the extent of recrystallization. The kinetics of recrystallization appeared to originate in the cold worked state, where three kinds of grain were found: (i) smooth elongated, featureless of α-fiber orientation {001}<100>; (ii) irregular fishbone grains of the γ-fiber orientations {111}<112> plus {111}<110>; and (iii) twisted grains of the η-fiber orientation {001}<100>. It was found that the twisted grains of the η-fiber were the first to recrystallize, with the fishbone grains of the γ-fiber second, and the smooth elongated, featureless grains of the α-fiber last. It was found that the grains of the α-fiber orientation {001}<100> and the η-fiber orientation {001}<100> were replaced with grains of the γ-fiber orientations as recrystallization progressed. These results are discussed in terms of recrystallization and texture development.

scholarly journals Kinetic investigation of AISI 304 Stainless Steel boronized in indirect heated fluidized bed furnace

2016 ◽  
Vol 52 (1) ◽  
pp. 63-68 ◽  
Author(s):  
P. Topuz ◽  
B. Çiçek ◽  
O. Akar
Keyword(s):  
Stainless Steel ◽  
Fluidized Bed ◽  
Optical Microscope ◽  
Boride Layer ◽  
Layer Growth ◽  
304 Stainless Steel ◽  
X Ray Diffraction ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Kinetics Of

In this study, kinetic examinations on boronized AISI 304 Stainless Steel samples were described. Samples were boronized in indirect heated fluidized bed furnace consists of Ekabor 1? boronizing agent at 1123, 1223 and 1323 K for 1,2 and 4 hours. Morphologically and typically examinations of borides formed on the surface of steel samples were studied by optical microscope, scanning electron microscope (SEM) and X-Ray diffraction (XRD). Boride layer thickness formed on the steel X5CrNi 18-10 ranges from 12 to 176 ?m. The hardness of the boride layer formed on the steel X5CrNi 18-10 varied between 1709 and 2119 Hv0,1. Layer growth kinetics were analyzed by measuring the extent of penetration of FeB and Fe2B sublayers as a function of boronizing time and temperature. The kinetics of the reaction has been determined with K=Ko exp (-Q/RT) equation. Activation energy (Q) of boronized steel X5CrNi 18-10 was determined as 244 kj/mol.

Grain Growth Kinetics of a Ti+Nb Stabilized 12%Cr Ferritic Stainless Steel at High Temperature

2011 ◽  
Vol 66-68 ◽  
pp. 108-113 ◽  
Author(s):  
Chang Jiang Song ◽  
Liang Zhu ◽  
Yuan Yi Guo ◽  
Ke Feng Li ◽  
Feng Mei Sun ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Grain Growth ◽  
Ferritic Stainless Steel ◽  
Growth Exponent ◽  
Growth Behaviour ◽  
Small Particles ◽  
Grain Growth Kinetics ◽  
Kinetics Of ◽  
Very High

By using a thermal simulator this work investigated grain growth behaviour of a Ti+Nb stabilized 12%Cr ferritic stainless steel at high temperature. The results showed that the grain growth rate was less than 1.8μm/s at the temperature of 1200°C, but it suddenly became very high and reached about 50μm/s when the temperature was 1250°C. Analysis results indicate that grain growth of this steel is affected by the small particles on the grain boundaries, and grain growth exponent is about 3.3. Moreover, the activation energy of the grain growth is when the temperature is above 1250°C. Compared with a 27Cr ferritic stainless steel containing only 0.14%Nb, the grain growth exponent of this steel is greater, and grain initial rapid growth temperature is higher.

Oxidation Kinetics of AISI 441 Ferritic Stainless Steel at High Temperatures in CO2 Atmosphere

2013 ◽  
Vol 81 (3-4) ◽  
pp. 315-329 ◽  
Author(s):  
Piyorose Promdirek ◽  
Gobboon Lothongkum ◽  
Somrerk Chandra-Ambhorn ◽  
Yves Wouters ◽  
Alain Galerie
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
High Temperatures ◽  
Oxidation Kinetics ◽  
Kinetics Of ◽  
Co2 Atmosphere
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