Effect of Al Additions on Scale Structure and Oxidation Kinetics of 430-Ferritic Stainless Steel Reheated in a Combustion Atmosphere

Author(s):  
Richard Osei ◽  
Simon Lekakh ◽  
Ronald O’Malley
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 ◽  
...  

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. 


2013 ◽  
Vol 81 (3-4) ◽  
pp. 315-329 ◽  
Author(s):  
Piyorose Promdirek ◽  
Gobboon Lothongkum ◽  
Somrerk Chandra-Ambhorn ◽  
Yves Wouters ◽  
Alain Galerie

2017 ◽  
Vol 103 (4) ◽  
pp. 184-193 ◽  
Author(s):  
Yoshiharu Inoue ◽  
Nobuhiko Hiraide ◽  
Atsutaka Hayashi ◽  
Kohsaku Ushioda

2012 ◽  
Vol 715-716 ◽  
pp. 437-446
Author(s):  
Anna P. Kisko ◽  
Pasi P. Suikkanen ◽  
C. Isaac Garcia ◽  
K. Cho ◽  
M. Hua ◽  
...  

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.


2017 ◽  
Vol 36 (2) ◽  
pp. 55-66 ◽  
Author(s):  
Kh. Farjam Hajiagha ◽  
A. R. Akbari ◽  
R. Mohammadzadeh ◽  
◽  
◽  
...  

2011 ◽  
Vol 66-68 ◽  
pp. 108-113 ◽  
Author(s):  
Chang Jiang Song ◽  
Liang Zhu ◽  
Yuan Yi Guo ◽  
Ke Feng Li ◽  
Feng Mei Sun ◽  
...  

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.


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