Abstract
The creep behavior of various pack cementation aluminide coatings on Grade 91 ferritic-martensitic steel was investigated at 650. °C in laboratory air. The coatings were fabricated in two temperature regimes, i.e., 650 or 700. °C (low temperature) and 1050. °C (high temperature), and consisted of a range of Al levels and thicknesses. For comparison, uncoated specimens heat-treated at 1050. °C to simulate the high temperature coating cycle also were included in the creep test. All coated specimens showed a reduction in creep resistance, with 16-51% decrease in rupture life compared to the as-received bare substrate alloy. However, the specimens heat-treated at 1050. °C exhibited the lowest creep resistance among all tested samples, with a surprisingly short rupture time of <. 25. h, much shorter than the specimen coated at 1050. °C. Factors responsible for the reduction in creep resistance of both coated and heat-treated specimens were discussed.
Original language | English |
---|---|
Pages (from-to) | 32-39 |
Number of pages | 8 |
Journal | Surface and Coatings Technology |
Volume | 240 |
DOIs | |
State | Published - Feb 15 2014 |
Funding
The authors would like to acknowledge funding by the Department of Energy (DOE) Advanced Coal Research at U.S. Colleges and Universities , under Grant No. DE-FG26-06NT42674 . Additional support is from DOE Fossil Energy Advanced Materials Research Program , under contract DE-AC05-00OR22725 with UT-Battelle LLC and subcontract 4000071336 with Tennessee Technological University .
Keywords
- Aluminide coatings
- Creep
- Ferritic-martensitic steel
- Hardness
- Pack cementation