Fatigue Deformation Behavior of Al_2O_3 Thermal Spray Coating at High Temperature

2002 ◽  
Vol 2002.40 (0) ◽  
pp. 83-84
Author(s):  
Rongguang WANG ◽  
Masahiro YAMAZAKI ◽  
Mitsuo KIDO
2018 ◽  
Vol 284 ◽  
pp. 1151-1156
Author(s):  
Lenar N. Shafigullin ◽  
A.R. Ibragimov ◽  
A.I. Saifutdinov

C. C. Berndt advanced investigations of mechanical properties of thermal spray coatings under 4-point bending. He found that this investigation method is sensitive to the mechanical properties of thermal spray coatings.This paper contains the detailed investigation results for thermal spray coatings of zirconium dioxide under 4-point bending, i.e. tests of the specimens subjected to spraying at varying conditions and pre-test soaking with the various duration at 1100 °С.It was established how the mechanical properties of thermal spray coatings changed depending on the spraying mode and high temperature soaking. The test results show that the double heat treatment of coatings is more preferable than one-time heat treatment as it make the properties change linearly. It is more easily controllable during operation of the components with thermal spray coating.


1997 ◽  
Vol 251-254 ◽  
pp. 809-816 ◽  
Author(s):  
G.R. Heath ◽  
P. Heimgartner ◽  
G. Irons ◽  
Robert D. Miller ◽  
Stefan Gustafsson

Coatings ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 709-723 ◽  
Author(s):  
Jarkko Metsäjoki ◽  
Maria Oksa ◽  
Satu Tuurna ◽  
Juha Lagerbom ◽  
Jouko Virta ◽  
...  

Particuology ◽  
2009 ◽  
Vol 7 (5) ◽  
pp. 368-372 ◽  
Author(s):  
Yangbao Qian ◽  
Linzhong Du ◽  
Weigang Zhang

Author(s):  
Stephen R. Swartz

Since the inception of the cyclone style boiler, industry has become accustomed to performing routine maintenance during every scheduled shutdown occurring 12 months to 18 months between cycles. These maintenance cycles are influenced by service factor, loading and the type design. The same problems exist in both the standard and super critical cyclones; severe deterioration of refractory and the anchoring pin studs. This paper focuses on one type of refractory failure mechanism caused by the anchoring pin studs. Most operators have found that the most effective means of applying refractory in this type situation is to “ram” the refractory in and around the anchoring pin studs thus creating a dense lining with maximum integrity. Coupled with proper application of anchoring pin studs and a special designed coating, typical volumetric expansion of the pin studs from corrosion attack and oxidation is eliminated thus extending the life of the refractory. This mechanism is discussed along with the results of the coating performance as it relates to extreme heat oxidation and thermal cycling in laboratory tests. A protective coating was developed using a nano-cored thermal spray wire technology that produces a uniform, adherent protective layer against high temperature corrosion and oxidation. The coating yields similar thermal conductivity as a bare stud thus experiencing excellent thermal cycle performance. This specially designed thermal spray coating is applied to standard 430 stainless steel pin studs thus providing the necessary barrier against aggressive high temperature environments while maintaining excellent heat conductivity. The coating has a high amount of tungsten (40+%) in a nickel matrix with greatly reduced oxides at the substrate and throughout the coating. With these attributes for the anchoring pin studs in mind, a newly designed stud was evaluated in heat oxidation tests up to 2000°F and thermal cycling test and compared to 430 stainless steel, chromized and Alloy 625. The new stud out-performed all others even in the as-welded condition. Further corrosion testing in ferric chloride (ASTM G48) showed them to be superior to Alloy 72 and Alloy 625 in the thermal spray and welded condition. Proper welding equipment and welding techniques are also discussed since weld continuity impacts overall performance of anchoring pin studs with refractory linings. A major test site will be examined in the spring of 2004 for it’s full effectiveness in service and will be documented in order that all data retrieved would be available to the entire industry.


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