Diffusion Layers with Ti and Ti+Al Formed on 316L Austenitic Steel by a Pack Cementation Procedure
| Periodical | Defect and Diffusion Forum (Volumes 312 - 315) |
|---|---|
| Main Theme | Diffusion in Solids and Liquids VI |
| Edited by | Andreas Öchsner, Graeme E. Murch and João M.P.Q. Delgado |
| Pages | 13-19 |
| DOI | 10.4028/www.scientific.net/DDF.312-315.13 |
| Citation | Iulia Mirela Britchi et al., 2011, Defect and Diffusion Forum, 312-315, 13 |
| Online since | April, 2011 |
| Authors | Iulia Mirela Britchi, Mircea Olteanu, Niculae Ene, Petru Nita |
| Keywords | 316L Austenitic Steel, Pack Cementation Procedure, Ti Diffusion, Ti+Al Simultaneous Diffusion |
| Price | US$ 28,- |
Pack cementation procedure implies the use of a powder mixture containing the diffusive elements, which in our case are either Ti or Ti+Al, Al2O3 and NHCl as activator. In the case of titanizing the powder mixture contained 77% in weight Ti, while for alumino-titanizing Al/Ti = 1/5 ratio was employed. NH4Cl content was 3% in weight in all cases. Aluminium additions to the powder mixtures led to a decrease of the process temperature. Activation energy for the aluminizing of austenitic 316L steel is 73.87 KJ/mol, much smaller than for the titanizing, 257.86 KJ/mol. Activation energy for alumino-titanizing, in the same conditions, is 146.01 KJ/mol. All diffusion coatings, in the Ti – 316L and Ti+Al – 316L couples are formed of two layers having different structures and compositions. All couples were investigated by optical microscopy, electron microscopy (SEM and EDX), X-ray diffraction and microhardness trials.
