D 2005

CARBON AND NITROGEN REDISTRIBUTION IN WELD JOINTS OF HEAT RESISTANT STEELS

SOPOUŠEK, Jiří and Rudolf FORET

Basic information

Original name

CARBON AND NITROGEN REDISTRIBUTION IN WELD JOINTS OF HEAT RESISTANT STEELS

Name in Czech

Přerozdělení uhlíku a dusíku ve svarových spojích žárovzdorných ocelí

Name (in English)

CARBON AND NITROGEN REDISTRIBUTION IN WELD JOINTS OF HEAT RESISTANT STEELS

Authors

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

Edition

Roma, 1-st International Conference Super-High Strenght Steels, p. 60/1-9, 9 pp. 2005

Publisher

Associazione Italiana di Metallurgia

Other information

Language

Czech

Type of outcome

Stať ve sborníku

Field of Study

10403 Physical chemistry

Country of publisher

Italy

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14310/05:00012734

Organization unit

Faculty of Science

ISBN

88-85298-56-7

Keywords in English

weldment;phase;DICTRA;CALPHAD;P91;carbonitride
Změněno: 27/1/2006 16:07, prof. RNDr. Jiří Sopoušek, CSc.

Abstract

V originále

The present contribution deals with the theoretical modelling of the kinetics of the development of chemical composition and phase profiles of heterogeneous laboratory weld joints of heat resistant steels from the point of view of their long-term stability. The T25 ( 6 CrMoV 8-3-2) heat-resistant ferritic steel currently being developed and the advanced P91 (X10CrMoVNb 10-1) chromium steel, both steels after ion nitriding, homogenisation at 1050şC and weld joining were the subject of study. The basic compositions of materials were approximated as the Fe-Cr-Ni-Mo-V-C-N system. The long-term annealing of the T25+0.1129wt%N | P91+(0.8-0.064wt)N weld joints were simulated at 600şC and 900şC. The simulated results were compared with experimental carbon profile observations. The phase diagrams of the investigated materials were calculated using the CALPHAD approach [1] and applying the STEEL thermodynamic database [2]. The activities of carbon, nitrogen, and other elements were calculated by the same method. The CALPHAD approach complemented with an appropriate diffusion model [3] given in the DICTRA code enabled simulating the phase and element profile evolutions inside the diffusion-affected zone of weld joint. The DIF kinetic database [4] was used to describe the diffusion. In the simulation the coexistence of different phases (carbides, carbonitrides,) was assumed.

In English

The present contribution deals with the theoretical modelling of the kinetics of the development of chemical composition and phase profiles of heterogeneous laboratory weld joints of heat resistant steels from the point of view of their long-term stability. The T25 ( 6 CrMoV 8-3-2) heat-resistant ferritic steel currently being developed and the advanced P91 (X10CrMoVNb 10-1) chromium steel, both steels after ion nitriding, homogenisation at 1050şC and weld joining were the subject of study. The basic compositions of materials were approximated as the Fe-Cr-Ni-Mo-V-C-N system. The long-term annealing of the T25+0.1129wt%N | P91+(0.8-0.064wt)N weld joints were simulated at 600şC and 900şC. The simulated results were compared with experimental carbon profile observations. The phase diagrams of the investigated materials were calculated using the CALPHAD approach [1] and applying the STEEL thermodynamic database [2]. The activities of carbon, nitrogen, and other elements were calculated by the same method. The CALPHAD approach complemented with an appropriate diffusion model [3] given in the DICTRA code enabled simulating the phase and element profile evolutions inside the diffusion-affected zone of weld joint. The DIF kinetic database [4] was used to describe the diffusion. In the simulation the coexistence of different phases (carbides, carbonitrides,) was assumed.

Links

GA106/03/0636, research and development project
Name: Teoretické modelování a experimentální studium strukturní stability moderních žárupevných ocelí a jejich svarů
MSM0021622410, plan (intention)
Name: Fyzikální a chemické vlastnosti pokročilých materiálů a struktur
Investor: Ministry of Education, Youth and Sports of the CR, Physical and chemical properties of advanced materials and structures