CARBON AND NITROGEN REDISTRIBUTION IN WELD JOINT OF ION-NITRIDED 15CrMoV2-5-3 AND ADVANCED P91 HEAT-RESISTANT STEELS
| Authors | |
|---|---|
| Year of publication | 2006 |
| Type | Article in Periodical |
| Magazine / Source | Journal of Phase Equilibria and Diffusion |
| MU Faculty or unit | |
| Citation | |
| Web | web of sci |
| Field | Physical chemistry and theoretical chemistry |
| Keywords | weldment; steel; DICTRA; carbon profile; simulation; nitrogen profile |
| Attached files | |
| Description | The present contribution compares the theoretical modelling of the kinetics of the development of chemical composition and phase profiles of heterogeneous laboratory weld joints of heat resistant steels after long-term annealing with earlier obtained experimental results. The weld joints of ion- nitrided 15CrMoV2-5-3 low-alloy ferritic steel and the advanced P91 steel (X10CrMoVNb 10-1) are the subject of study. The long-term annealing of the (nitrided 15CrMoV 2-5-3) | P91 weld joint was simulated at 500-700 degree of C (i.e. 773-973K). The simulated results were compared with earlier experimental carbon and nitrogen profile measurements. The phase diagrams of the investigated materials were calculated using the CALPHAD approach making use of the STEEL thermodynamic database. The activities of both carbon and nitrogen were calculated by the same method. The CALPHAD approach complemented with an appropriate diffusion model given in the DICTRA programme enabled simulating the phase and element profile evolutions inside the diffusion-affected zone of weld joint. The DIF kinetic database was used to describe the diffusion. The coexistence of different phases (carbides, carbonitrides, ...) was considered in the simulations. The results show very reasonable agreement between experiment and theoretical simulation, and the method used is very promising for further weld design. |
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