Weld Joints Simulations of Heat-resistant Steels

D 2004

Weld Joints Simulations of Heat-resistant Steels

SOPOUŠEK, Jiří and Rudolf FORET

Basic information

Original name

Weld Joints Simulations of Heat-resistant Steels

Name in Czech

Simulace svarových spojů žáropevných ocelí

Authors

SOPOUŠEK, Jiří (203 Czech Republic) and Rudolf FORET (203 Czech Republic, guarantor)

Edition

Krakow, CALPHAD XXXIII, p. 148-148, 2004

Publisher

Institute of Metallurgy and Material Science, Krakow, Polish Academy of Sciences

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

10403 Physical chemistry

Country of publisher

Poland

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14310/04:00011448

Organization unit

Faculty of Science

Keywords in English

diffusion; couple; DICTRA; ThermoCalc; Equilibrium; Activity

Abstract

ORIG CZ

V originále

Knowledge of microstructure stabilities is essential for reliable estimations of the lifetime limitations of materials and welded joints at higher temperatures. This information may be deduced from material phase diagrams and from heterogeneous weld joint simulations. The phase diagrams can be calculated using CALPHAD method [1]. This method complemented with appropriate diffusion approach [2], [3] can help us to simulate phase and element profile evolutions inside diffusion-affected zone of weld joint too. The heat-resistant steels (alloying base: Cr, Ni, Mo, V, C, N) and their weld joints are objects of our study. Thermodynamic database STEEL [4] and kinetic database DIF mentioned in [5] are used. The particullar results of the equilibrium calculations are presented as the phase diagram cross-sections of the selected heat-resistance steels. The same equilibrium calculations offer element activities too. The carbon activity temperature dependences were calculated for individual steels. The observed difference between the carbon activities of two different steels (at given temperature) enabled us to predict diffusion flow direction, which can be opposite then deduced from the carbon content in some steel combinations (carbon up-hill diffusion). The simulations respect the coexistence of different carbide phases in the materials and they are conducted on the assumption that under the examined conditions the local phase equilibrium holds and that diffusion is the control process of phase transformation. The phase diagram calculations and diffusion couple simulations involving time-distance dependences for phase and element redistributions in diffusion-affected zones enabled us to obtain a basic information, which allow to estimate thermodynamic and diffusion stabilities of the studied heat-resistant steels and their weld joints.

In Czech

Pro oceli na bázi Cr, Ni, Mo, V, C, V jsou predikovány fázové diagramy metodou CALPHAD. Pro sledované oceli jsou vypočteny aktivitní teplotní závislosti uhlíku. Je sledován i případ difúze proti koncentračnímu spádu. Součástí práce je simulace difúzních profilů sledovaných kombinací svarových spojů.

Links

GA106/03/0636, research and development project

Name: Teoretické modelování a experimentální studium strukturní stability moderních žárupevných ocelí a jejich svarů

Citovat

SOPOUŠEK, Jiří and Rudolf FORET. Weld Joints Simulations of Heat-resistant Steels. In CALPHAD XXXIII. Krakow: Institute of Metallurgy and Material Science, Krakow, Polish Academy of Sciences, 2004, p. 148.

@inproceedings{555568,
   author = {Sopoušek, Jiří and Foret, Rudolf},
   address = {Krakow},
   booktitle = {CALPHAD XXXIII},
   keywords = {diffusion; couple; DICTRA; ThermoCalc; Equilibrium; Activity},
   language = {eng},
   location = {Krakow},
   pages = {148-148},
   publisher = {Institute of Metallurgy and Material Science, Krakow, Polish Academy of Sciences},
   title = {Weld Joints Simulations of Heat-resistant Steels},
   year = {2004}
}

TY  - JOUR
ID  - 555568
AU  - Sopoušek, Jiří - Foret, Rudolf
PY  - 2004
TI  - Weld Joints Simulations of Heat-resistant Steels
PB  - Institute of Metallurgy and Material Science, Krakow, Polish Academy of Sciences
CY  - Krakow
KW  - diffusion
KW  - couple
KW  - DICTRA
KW  - ThermoCalc
KW  - Equilibrium
KW  - Activity
N2  - Knowledge of microstructure stabilities is essential for reliable estimations of the lifetime limitations of materials and welded joints at higher temperatures. This information may be deduced from material phase diagrams and from heterogeneous weld joint simulations. The phase diagrams can be calculated using CALPHAD method [1]. This method complemented with appropriate diffusion approach [2], [3] can help us to simulate phase and element profile evolutions inside diffusion-affected zone of weld joint too. The heat-resistant steels (alloying base: Cr, Ni, Mo, V, C, N) and their weld joints are objects of our study. Thermodynamic database STEEL [4] and kinetic database DIF mentioned in [5] are used. The particullar results of the equilibrium calculations are presented as the phase diagram cross-sections of the selected heat-resistance steels. The same equilibrium calculations offer element activities too. The carbon activity temperature dependences were calculated for individual steels. The observed difference between the carbon activities of two different steels (at given temperature) enabled us to predict diffusion flow direction, which can be opposite then deduced from the carbon content in some steel combinations (carbon up-hill diffusion). The simulations respect the coexistence of different carbide phases in the materials and they are conducted on the assumption that under the examined conditions the local phase equilibrium holds and that diffusion is the control process of phase transformation. The phase diagram calculations and diffusion couple simulations involving time-distance dependences for phase and element redistributions in diffusion-affected zones enabled us to obtain a basic information, which allow to estimate thermodynamic and diffusion stabilities of the studied heat-resistant steels and their weld joints.
ER  -

SOPOUŠEK, Jiří and Rudolf FORET. Weld Joints Simulations of Heat-resistant Steels. In \textit{CALPHAD XXXIII}. Krakow: Institute of Metallurgy and Material Science, Krakow, Polish Academy of Sciences, 2004, p.~148.

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