51312-01740-Development of diffusion coatings to optimize the high temperature corrosion resistance of reformer

Available for download

Product Number: 51312-01740-SG

ISBN: 01740 2012 CP

Author: Ammar Naji

Publication Date: 2012

Member Price: $0.00

Non Member Price: $20.00

Price: $20.00

Qty:

Reformer materials are exposed to severe operating conditions at high temperature (1000°C) in aggressive catalyzer and combustion atmospheres. Reactors of this type exhibit damages to the welds and the reactor cap.In the paper the development of diffusion coatings by a pack cementation process is reported that provides high temperature corrosion protection for these materials.Thermocyclic tests of uncoated high-alloyed (Ni-Base and high-alloyed Fe-Base) materials and diffusion (Al) and co-diffusion (Al-Si) coated low-alloyed Fe-Base materials in a combustion (52% N2 32% H2O 13% CO2 3% O2) and catalyzer atmosphere (55% H2 28% H2O 8% CO2 7.5% CO 1.5% CH4) showed that the corrosion resistance of coated materials is significantly higher in comparison to the uncoated materials. These coatings were furthermore optimized by adding small quantities of reactive elements (e.g. Y Hf Ce) that improve scale adhesion.By means of the programs FactSage and COMSOL Multiphysics the diffusion treatment of coated materials can be simulated and compared with the experimental results. Besides the development of an efficient coating one of the goals is to support a more sophisticated understanding of the diffusion process and to design the coating process on the basis of a thermodynamic and kinetic model. This approach will be discussed in the paper.Keywords: Reformer reactor diffusion coating co-deposition reactive elements cyclic oxidation simulative analysis