D 2005

THERMODYNAMIC AND KINETIC SIMULATIONS OF POST WELD HEAT TREATMENT APLICATED ON P91/P22 JOINT OF STEELS

SOPOUŠEK, Jiří and Luboš PRCHLÍK

Basic information

Original name

THERMODYNAMIC AND KINETIC SIMULATIONS OF POST WELD HEAT TREATMENT APLICATED ON P91/P22 JOINT OF STEELS

Name in Czech

Termodynamická a kinetická simulace posvarového žíhání na odstranění pnutí použitá pro P91/P22 spojení ocelí

Authors

SOPOUŠEK, Jiří (203 Czech Republic, guarantor) and Luboš PRCHLÍK (203 Czech Republic)

Edition

2005. vyd. Brno, V. Pracovní setkání fyzikálních chemiků a elektrochemiků, p. 84-86, 3 pp. 2005

Publisher

Masarykova univerzita v Brně

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

10403 Physical chemistry

Country of publisher

Czech Republic

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14310/05:00012373

Organization unit

Faculty of Science

Keywords in English

Equilibria;Calphad;DICTRA; weld;steel;heat-resistant
Změněno: 27/1/2006 16:22, prof. RNDr. Jiří Sopoušek, CSc.

Abstract

V originále

Weld joints between dissimilar materials represent critical locations of structures operating at high temperatures. Among other industries, dissimilar joints are increasingly used in power generation & turbomachinery. The evaluation of diffusion-controlled processes is extremely valuable, since it allows estimating long-term mechanical and microstructural stability of dissimilar welds. Diffusion and phase transformation processes were studied theoretically for P91/P22 weld joint. Modified material P91 (0.14wt%C, 10.5%Cr, 1.5%Mo, 0.6%Ni, 0.2%V, 0.04%N 0.04%Nb) represents progressive chromium steel and material P22 (0.07%C, 2.3Cr, 0,9%Mo) can be used as weld alloy. CALPHAD approach1 and thermodynamic database STEEL2 were used for thermodynamic descriptions. It enables to predict phase diagrams and activity temperature dependences of the steels. The simulated weld joint was approximated as a diffusion couple after post weld heat treatment (PWHT). Diffusion-controlled processes were described using the same method as described. DICTRA program and kinetic database DIF5 were used for diffusion simulation. The calculated carbon activity difference shows that the carbon tends to diffuse from material P22 with low carbon content to material P91 with high carbon content (up-hill diffusion) as illustrated. The simulation of the diffusion process using described approach enabled to obtain results presented. The final carbon profile shows up-hill diffusion and carbon-depleted zone in material P22. The phase profiles indicate that complex phase transformations can be supposed inside diffusion-affected zone. These transformations produce for example LAVES phase inside carbon depleted zone and M23C6 carbide inside carbon enriched zone. The thermodynamic/kinetic simulation of post weld heat treatment of the P91/P22 joint shows how it is possible now to reduce time and money consuming experiments and optimise welding consumables used.

In Czech

Termodynamická a kinetická simulace posvarového žíhání na odstranění pnutí použitá pro P91/P22 spojení ocelí

Links

GA106/03/0636, research and development project
Name: Teoretické modelování a experimentální studium strukturní stability moderních žárupevných ocelí a jejich svarů
GA106/94/0307, research and development project
Name: Vztah mezi strukturou a termodynamickými vlastnostmi soustav na bázi přechodových kovů s uhlíkem a dusíkem
Investor: Czech Science Foundation, The Relations Between the Structure and Thermodynamic Properties of the Transition Metals Based Systems with Carbon and/or Nitrogen
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