Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

2 Citations (Scopus)

Abstract

Standardised methods for the assessment of hydrogen cracking risk are mostly developed for HAZ cracking cases, where cracking often occurs as root cracking. The applied experiments are therefore usually single-pass cracking tests. For multiple-pass welding, and when the cracking sensitivity of weld metal dictates the required preheat, European standards do not give reliable guidance on how to assess the need of preheat. Standard EN 1011-2 considers the possibility of weld metal cracking, however, it does not provide the user with a validated methodology for the calculation of the actual level of 'safe' preheat temperature. The suitability of a given standard procedure, or calculation method, for multipass welds therefore has to be investigated on case by case basis. This paper is concerned with the assessment of required preheat/interpass temperature for the avoidance of hydrogen cracking in matching type multipass weld metal in a 2.25%Cr-1.0%Mo-0.25%V boiler steel using experimental and numerical methods. The applied methods were: (i) EN 1011-2 Method, (ii) Crack no crack diagram method developed by VTT, and (iii) deep-notch Implant test based analytical method developed by Osaka University and VTT. Necessary precautions for safe welding are given. Recent developments in numerical modelling of hydrogen diffusion in multipass welding are discussed.
Original languageEnglish
Title of host publicationBALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2
PublisherVTT Technical Research Centre of Finland
Pages393-407
ISBN (Electronic)951-38-6294-1
ISBN (Print)951-38-6293-3
Publication statusPublished - 2004
MoE publication typeB3 Non-refereed article in conference proceedings
EventBALTICA VI - Life Management and Maintenance for Power Plants - Helsinki-Stockholm, Finland
Duration: 8 Jun 200410 Jun 2004

Publication series

NameVTT Symposium
PublisherVTT Industrial Systems
Number234
ISSN (Print)0357-9387
ISSN (Electronic)1455-0873

Conference

ConferenceBALTICA VI - Life Management and Maintenance for Power Plants
CountryFinland
CityHelsinki-Stockholm
Period8/06/0410/06/04

Fingerprint

Boilers
Welds
Hydrogen
Welding
Steel
Metals
Cracks
Numerical methods
Temperature
Experiments

Keywords

  • ProperTune

Cite this

Nevasmaa, P., Laukkanen, A., & Häkkilä, J. (2004). Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel. In BALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2 (pp. 393-407). VTT Technical Research Centre of Finland. VTT Symposium, No. 234
Nevasmaa, Pekka ; Laukkanen, Anssi ; Häkkilä, Juha. / Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel. BALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2. VTT Technical Research Centre of Finland, 2004. pp. 393-407 (VTT Symposium; No. 234).
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abstract = "Standardised methods for the assessment of hydrogen cracking risk are mostly developed for HAZ cracking cases, where cracking often occurs as root cracking. The applied experiments are therefore usually single-pass cracking tests. For multiple-pass welding, and when the cracking sensitivity of weld metal dictates the required preheat, European standards do not give reliable guidance on how to assess the need of preheat. Standard EN 1011-2 considers the possibility of weld metal cracking, however, it does not provide the user with a validated methodology for the calculation of the actual level of 'safe' preheat temperature. The suitability of a given standard procedure, or calculation method, for multipass welds therefore has to be investigated on case by case basis. This paper is concerned with the assessment of required preheat/interpass temperature for the avoidance of hydrogen cracking in matching type multipass weld metal in a 2.25{\%}Cr-1.0{\%}Mo-0.25{\%}V boiler steel using experimental and numerical methods. The applied methods were: (i) EN 1011-2 Method, (ii) Crack no crack diagram method developed by VTT, and (iii) deep-notch Implant test based analytical method developed by Osaka University and VTT. Necessary precautions for safe welding are given. Recent developments in numerical modelling of hydrogen diffusion in multipass welding are discussed.",
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Nevasmaa, P, Laukkanen, A & Häkkilä, J 2004, Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel. in BALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2. VTT Technical Research Centre of Finland, VTT Symposium, no. 234, pp. 393-407, BALTICA VI - Life Management and Maintenance for Power Plants, Helsinki-Stockholm, Finland, 8/06/04.

Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel. / Nevasmaa, Pekka; Laukkanen, Anssi; Häkkilä, Juha.

BALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2. VTT Technical Research Centre of Finland, 2004. p. 393-407 (VTT Symposium; No. 234).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

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T1 - Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel

AU - Nevasmaa, Pekka

AU - Laukkanen, Anssi

AU - Häkkilä, Juha

PY - 2004

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N2 - Standardised methods for the assessment of hydrogen cracking risk are mostly developed for HAZ cracking cases, where cracking often occurs as root cracking. The applied experiments are therefore usually single-pass cracking tests. For multiple-pass welding, and when the cracking sensitivity of weld metal dictates the required preheat, European standards do not give reliable guidance on how to assess the need of preheat. Standard EN 1011-2 considers the possibility of weld metal cracking, however, it does not provide the user with a validated methodology for the calculation of the actual level of 'safe' preheat temperature. The suitability of a given standard procedure, or calculation method, for multipass welds therefore has to be investigated on case by case basis. This paper is concerned with the assessment of required preheat/interpass temperature for the avoidance of hydrogen cracking in matching type multipass weld metal in a 2.25%Cr-1.0%Mo-0.25%V boiler steel using experimental and numerical methods. The applied methods were: (i) EN 1011-2 Method, (ii) Crack no crack diagram method developed by VTT, and (iii) deep-notch Implant test based analytical method developed by Osaka University and VTT. Necessary precautions for safe welding are given. Recent developments in numerical modelling of hydrogen diffusion in multipass welding are discussed.

AB - Standardised methods for the assessment of hydrogen cracking risk are mostly developed for HAZ cracking cases, where cracking often occurs as root cracking. The applied experiments are therefore usually single-pass cracking tests. For multiple-pass welding, and when the cracking sensitivity of weld metal dictates the required preheat, European standards do not give reliable guidance on how to assess the need of preheat. Standard EN 1011-2 considers the possibility of weld metal cracking, however, it does not provide the user with a validated methodology for the calculation of the actual level of 'safe' preheat temperature. The suitability of a given standard procedure, or calculation method, for multipass welds therefore has to be investigated on case by case basis. This paper is concerned with the assessment of required preheat/interpass temperature for the avoidance of hydrogen cracking in matching type multipass weld metal in a 2.25%Cr-1.0%Mo-0.25%V boiler steel using experimental and numerical methods. The applied methods were: (i) EN 1011-2 Method, (ii) Crack no crack diagram method developed by VTT, and (iii) deep-notch Implant test based analytical method developed by Osaka University and VTT. Necessary precautions for safe welding are given. Recent developments in numerical modelling of hydrogen diffusion in multipass welding are discussed.

KW - ProperTune

M3 - Conference article in proceedings

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T3 - VTT Symposium

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BT - BALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2

PB - VTT Technical Research Centre of Finland

ER -

Nevasmaa P, Laukkanen A, Häkkilä J. Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel. In BALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2. VTT Technical Research Centre of Finland. 2004. p. 393-407. (VTT Symposium; No. 234).