Limits...
On the constitutive model of nitrogen-containing austenitic stainless steel 316LN at elevated temperature.

Zhang L, Feng X, Wang X, Liu C - PLoS ONE (2014)

Bottom Line: The constitutive model is developed through multiple linear regressions performed on the experimental data and based on an Arrhenius-type equation and Zener-Hollomon theory.The reliability and accuracy of the model is verified through the comparison of predicted flow stress curves and experimental curves.Possible reasons for deviation are also discussed based on the characteristics of modeling process.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Tsinghua University, Beijing, China.

ABSTRACT
The nitrogen-containing austenitic stainless steel 316LN has been chosen as the material for nuclear main-pipe, which is one of the key parts in 3rd generation nuclear power plants. In this research, a constitutive model of nitrogen-containing austenitic stainless steel is developed. The true stress-true strain curves obtained from isothermal hot compression tests over a wide range of temperatures (900-1250°C) and strain rates (10(-3)-10 s(-1)), were employed to study the dynamic deformational behavior of and recrystallization in 316LN steels. The constitutive model is developed through multiple linear regressions performed on the experimental data and based on an Arrhenius-type equation and Zener-Hollomon theory. The influence of strain was incorporated in the developed constitutive equation by considering the effect of strain on the various material constants. The reliability and accuracy of the model is verified through the comparison of predicted flow stress curves and experimental curves. Possible reasons for deviation are also discussed based on the characteristics of modeling process.

Show MeSH

Related in: MedlinePlus

Flow stress curves of 316LN steels compressed at different temperatures and strain rates.(a) 10−3 s−1, (b) 10−2 s−1, (b) 10−1 s−1, (b) 1 s−1 and (b) 10 s−1.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4222771&req=5

pone-0102687-g002: Flow stress curves of 316LN steels compressed at different temperatures and strain rates.(a) 10−3 s−1, (b) 10−2 s−1, (b) 10−1 s−1, (b) 1 s−1 and (b) 10 s−1.

Mentions: The true stress-true strain curves obtained from the experiments are shown in Fig. 2. It is clear that the flow stresses of 316LN steel are strongly affected by the experimental temperature, strain rate, and level of strain. Higher levels of flow stress are more likely at lower temperatures and higher strain rates. In addition, dynamic recrystallization is also affected by temperature and strain rate. The peaks on the flow stress curves, which indicate that dynamic recrystallization took place, can be observed only at relatively high temperatures (1000–1250°C) and low strain rates (10−3–10−1 s−1). At the other conditions, there are no obvious peaks on the flow stress curves, which means that the material softens by dynamic recovery rather than dynamic recrystallization. This is in good agreement with previous research [19].


On the constitutive model of nitrogen-containing austenitic stainless steel 316LN at elevated temperature.

Zhang L, Feng X, Wang X, Liu C - PLoS ONE (2014)

Flow stress curves of 316LN steels compressed at different temperatures and strain rates.(a) 10−3 s−1, (b) 10−2 s−1, (b) 10−1 s−1, (b) 1 s−1 and (b) 10 s−1.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4222771&req=5

pone-0102687-g002: Flow stress curves of 316LN steels compressed at different temperatures and strain rates.(a) 10−3 s−1, (b) 10−2 s−1, (b) 10−1 s−1, (b) 1 s−1 and (b) 10 s−1.
Mentions: The true stress-true strain curves obtained from the experiments are shown in Fig. 2. It is clear that the flow stresses of 316LN steel are strongly affected by the experimental temperature, strain rate, and level of strain. Higher levels of flow stress are more likely at lower temperatures and higher strain rates. In addition, dynamic recrystallization is also affected by temperature and strain rate. The peaks on the flow stress curves, which indicate that dynamic recrystallization took place, can be observed only at relatively high temperatures (1000–1250°C) and low strain rates (10−3–10−1 s−1). At the other conditions, there are no obvious peaks on the flow stress curves, which means that the material softens by dynamic recovery rather than dynamic recrystallization. This is in good agreement with previous research [19].

Bottom Line: The constitutive model is developed through multiple linear regressions performed on the experimental data and based on an Arrhenius-type equation and Zener-Hollomon theory.The reliability and accuracy of the model is verified through the comparison of predicted flow stress curves and experimental curves.Possible reasons for deviation are also discussed based on the characteristics of modeling process.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Advanced Materials Processing Technology of Ministry of Education, Tsinghua University, Beijing, China.

ABSTRACT
The nitrogen-containing austenitic stainless steel 316LN has been chosen as the material for nuclear main-pipe, which is one of the key parts in 3rd generation nuclear power plants. In this research, a constitutive model of nitrogen-containing austenitic stainless steel is developed. The true stress-true strain curves obtained from isothermal hot compression tests over a wide range of temperatures (900-1250°C) and strain rates (10(-3)-10 s(-1)), were employed to study the dynamic deformational behavior of and recrystallization in 316LN steels. The constitutive model is developed through multiple linear regressions performed on the experimental data and based on an Arrhenius-type equation and Zener-Hollomon theory. The influence of strain was incorporated in the developed constitutive equation by considering the effect of strain on the various material constants. The reliability and accuracy of the model is verified through the comparison of predicted flow stress curves and experimental curves. Possible reasons for deviation are also discussed based on the characteristics of modeling process.

Show MeSH
Related in: MedlinePlus