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.

Grain Growth in Nb-Alloyed Stainless Steel of AISI 347 during Heating

2013 ◽  
Vol 753 ◽  
pp. 345-348 ◽  
Author(s):  
Hai Wen Luo ◽  
Han Dong ◽  
Ling Feng Chen
Keyword(s):  
Activation Energy ◽  
Stainless Steel ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Isothermal Holding ◽  
Growth Exponent ◽  
Microalloyed Steels ◽  
Nb Content ◽  
Grain Growth Kinetics ◽  
Kinetics Of

Grain growth kinetics in an AISI 347 stainless steel with Nb content up to 0.7%wt was studied during the isothermal holding in the temperature range of 1100-1270°C for various periods. Abnormal grain growth was observed even in the presence of a large amount of precipitates. The kinetics of normal grain growth was tracked by metallographic measurements and fitted by the classical modeling, which led to two important parameters of activation energy Q and growth exponent n derived. Both of them are larger than the usual values for grain growth in the Nb-microalloyed steels due to the much larger content of Nb in the present steel.

β Grain Growth Kinetics of a New Metastable β Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 844-849 ◽  
Author(s):  
Yue Fei ◽  
Xin Nan Wang ◽  
Zhi Shou Zhu ◽  
Jun Li ◽  
Guo Qiang Shang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Grain Growth ◽  
Kinetic Equations ◽  
Type Equation ◽  
Growth Exponent ◽  
Solution Treated ◽  
Growth Activation ◽  
Grain Growth Kinetics ◽  
Kinetics Of ◽  
Strength And Ductility

Ti-Mo-Nb-Cr-Al-Fe-Si alloy is a new metastable β titanium alloy with excellent combination of strength and ductility. The β grain-growth exponent and the activation energies for β grain growth for the investigated alloy at specified temperature were computed by the kinetic equations and the Arrhenius-type equation. The rate of β grain growth decreases with elongating solution treated time and increases with the increasing solution-treated temperature. The β grain-growth exponents, n, are 0.461, 0.464 and 0.469 at 1113, 1133 and 1153K, respectively. The β grain growth activation energy is determined to be 274 KJ/mol.

Grain Growth Kinetics of Cobalt-Doped SnO2 by Varying Nb2O5 Content

2007 ◽  
Vol 534-536 ◽  
pp. 529-532 ◽  
Author(s):  
Dong Gyu Chang ◽  
Joon Hyung Lee ◽  
Jeong Joo Kim
Keyword(s):  
Grain Growth ◽  
Boundary Segregation ◽  
Growth Behavior ◽  
Grain Boundary Segregation ◽  
Growth Exponent ◽  
Space Charges ◽  
Grain Growth Kinetics ◽  
Grain Growth Behavior ◽  
Kinetics Of ◽  
Co Doped

SnO2 ceramics were co-doped with the aliovalent ions of CoO and Nb2O5 and the grain growth behavior of the SnO2 was investigated. When only CoO was doped, the grain growth exponent of SnO2 was 3. As the amount of Nb2O5 increased, the exponent changed from 3 to 2 when 0.505 mol% of Nb2O5 was added. The further addition of Nb2O5 changed the exponent from 2 to 3. When Nb2O5 content was 0.505 mol%, of which the grain growth exponent was 2, it is believed that an iso-electric point is formed without grain boundary segregation, since the respective space charges, generated by Nb5+ and Co3+ might compensate each other.

β Grain Growth Kinetics of Hot-Rolled TB-13 Alloy

2011 ◽  
Vol 689 ◽  
pp. 472-478 ◽  
Author(s):  
Yue Fei ◽  
Bin Tang ◽  
Hui Chang ◽  
Zhi Shou Zhu ◽  
Zhong Bo Zhou ◽  
...  
Keyword(s):  
Activation Energy ◽  
Grain Growth ◽  
Kinetic Equations ◽  
Type Equation ◽  
Growth Exponent ◽  
Fine Grained ◽  
Solution Treated ◽  
Grain Growth Kinetics ◽  
Hot Rolled ◽  
Kinetics Of

A study on the kinetics of β grain growth of a fine-grained, hot-rolled TB-13 alloy was carried out by isochronal and isothermal solution treatments. The grain size of the as-rolled and as-solution-treated samples was determined by metallographic observation using the linear intercept method. The kinetic equations and the Arrhenius-type equation were applied to calculate the β grain growth exponent and the activation energy for β grain growth at special temperatures. The results showed that the β grain growth rate decreased with elongating solution treated time, but increased with increasing solution treated temperature. The β grain growth exponents (n) were 0.394, 0.403 and 0.406 during the solution treated temperatures at 1103K, 1153K and 1203K, respectively. The values of n increased with increasing solution treated temperature and the determined activation energy (Qm) for β grain growth after holding for 0.5h at 1103K-1203K was around 156KJ/mol.

scholarly journals Effects of Boron Doping on the Grain Growth Behaviour of γ/γ Nickel-Aluminium Alloy

1999 ◽  
Vol 580 ◽  
Author(s):  
Y.L. Chiu ◽  
A.H.W. Ngan
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Boron Doping ◽  
Growth Behaviour ◽  
Boron Doped ◽  
Retarding Effect ◽  
Disordered Layer ◽  
Grain Growth Kinetics ◽  
First Time ◽  
Kinetics Of

AbstractEffects of 0.5 at. % boron doping on Ni85Al γ/γ superalloys were investigated for the first time, yielding a number of observations not previously observed in the literature. First, the grain growth kinetics of both the doped and undoped alloys were found to disobey the simple Nielsen law d = Ctn but instead follow an equation of the type d = C ln(t) + C0. The constants C and C0 were found to be respectively 10.2 and 23.2 for the boron-free alloy, and 6.2 and 14.2 for the boron-doped alloy, i.e., the grain growth rate was retarded significantly upon boron doping. Such a retarding effect is thought to be due to the formation of a boron-nickel cosegregated zone observed at the grain boundaries of the doped alloy; the width of the zone, in μm's, is two to three orders of magnitude larger than the boron induced disordered layer found in nickel rich Ni3Al compounds doped with boron. Other associated effects of the cosegregated zone include a sharp increase in toughness, much better slip transmission across grains and reduced workhardening rates. Another intriguing point is that the γ precipitates were found to segregate to the grain boundaries in the boron-free alloy after cold rolling, but no such segregation of γ precipitates has been observed in the boron-doped alloy. The different deformation microstructures and the retarded grain growth rates upon boron doping will be discussed.

Grain Growth Kinetics of Accumulative Roll Bonded AZ61 Alloy

2012 ◽  
Vol 585 ◽  
pp. 387-391 ◽  
Author(s):  
H. Shivananda Nayaka ◽  
Gajanan P. Chaudhari ◽  
B.S. Sunder Daniel
Keyword(s):  
Grain Growth ◽  
Growth Kinetics ◽  
Annealing Temperature ◽  
Isothermal Annealing ◽  
Arrhenius Equation ◽  
Growth Exponent ◽  
Az61 Magnesium Alloy ◽  
Ultrafine Grained ◽  
Grain Growth Kinetics ◽  
Kinetics Of

A detailed study was performed on the grain growth kinetics of ultrafine-grained AZ61 magnesium alloy produced by accumulative roll bonding by carrying out isothermal annealing treatments on the roll bonded samples. Annealing treatments were carried out in the temperature range 423 to 573K for 2 to 120 minutes. As the annealing time and temperature increased, the grain size increased. The effect of annealing temperature and time, on the grain growth can be well explained by the kinetic equation and Arrhenius equation. Based on the experimental results of grain growth during annealing treatments, the grain growth exponent and the activation energy for grain growth were determined. The grain growth kinetic parameters were compared with other magnesium alloys processed by various methods.

scholarly journals Cellular automata simulation for high temperature austenite grain growth based on thermal activation theory and curvature-driven mechanism

2016 ◽  
Vol 94 (12) ◽  
pp. 1353-1364 ◽  
Author(s):  
Min Wang ◽  
Yajun Yin ◽  
Jianxin Zhou ◽  
Hai Nan ◽  
Tong Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Grain Growth ◽  
Thermal Activation ◽  
Growth Exponent ◽  
Austenite Grain ◽  
Activation Theory ◽  
Different Temperatures ◽  
Curvature Driven ◽  
Austenite Grain Growth ◽  
Kinetics Of

Based on the thermal activation theory and curvature-driven mechanism, a 2D cellular automaton model with different state transition rules was built. Validity of the model was proved by the shrinking of circular grains. Grain growth of high temperature austenite was simulated by this model; the morphology, grain size distribution, topological aspects, and local kinetics of austenite grain growth were analyzed under different simulation time. Among the grains with different sides, the 6-sided grains are the most common and 5-sided grains are the second most common. The grains with more than six sides will grow and grains with less than six sides will shrink, while the 6-sided grains will neither grow nor shrink. The kinetics of normal grain growth follows the Burke equation and the growth exponent at different temperatures and activation energies has been researched.

ATI 409HP

Alloy Digest ◽  
2013 ◽  
Vol 62 (2) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Carbon Steel ◽  
Physical Properties ◽  
Tensile Properties ◽  
Ferritic Stainless Steel ◽  
Temperature Performance ◽  
End Use ◽  
Oxidation And Corrosion

Abstract ATI 409HP (UNS S40900) ferritic stainless steel was introduced by ATI Allegheny Ludlum to provide improved oxidation and corrosion resistance for automotive exhaust systems in comparison to carbon steel. The alloy was designated "MF-1", indicating its end use: automotive mufflers. The good fabricability of this alloy, combined with its basic corrosion resistance and economy have significantly broadened the utility of ATI 409HP stainless steel. ATI 409HP consists of four grades: UNS S40900, S40910, S40920, and S40930. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, and joining. Filing Code: SS-1135. Producer or source: Allegheny Technologies Inc..

AK STEEL 441

Alloy Digest ◽  
2006 ◽  
Vol 55 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Ferritic Stainless Steel ◽  
High Temperature Oxidation ◽  
High Temperature Strength ◽  
Temperature Oxidation ◽  
Temperature Performance

Abstract AK Steel 441 has good high-temperature strength, an equiaxed microstructure, and good high-temperature oxidation resistance. The alloy is a niobium-bearing ferritic stainless steel. This datasheet provides information on composition, hardness, and tensile properties as well as deformation. It also includes information on high temperature performance and corrosion resistance as well as forming and joining. Filing Code: SS-965. Producer or source: AK Steel.

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