| Autor: |
Ryzhenkov, A. V., Mednikov, A. F., Grigoriev, S. V., Tkhabisimov, A. B., Kachalin, G. V., Loginova, N. A., Milovanov, O. Yu. |
| Zdroj: |
Thermal Engineering; Oct2023, Vol. 70 Issue 10, p751-759, 9p |
| Abstrakt: |
The results of full-scale studies of the corrosion and abrasive resistance of the surfaces of experimental samples of tubular steel 20 with a protective ion-plasma coating based on Cr–CrN and without it during their exposure for 1000 h in the furnace of a boiler with a nominal capacity of 200 kW operating on granulated biofuels are presented. Samples were held at operating mode for 220 h, and at idle mode for 780 h. The temperature inside the rear smoke box, where the experimental samples were placed, was approximately 700°C. Chemical analysis of the composition of ash obtained during the burning of sunflower husks showed the presence of potassium, phosphorus, sulfur and chlorine, i.e., those elements whose presence can lead to the formation of highly aggressive corrosion-hazardous compounds when moisture is condensed during periods of boiler downtime. It was revealed that the studied coating was not subjected to corrosion destruction, its adhesive strength did not change during the holding time, the initial thickness of the coating decreased by an average of 10–15%, and the surface roughness remained the same. There was a slight deviation in the morphology due to oxidation of the surface layer of the coating at the maximum holding time, no oxidation of the material under the coating on the transverse splines of the coated samples was detected. Tests conducted at the incidence angles of the air-abrasive flow of 30°, 60° and 90° tests of steel samples 20 with a protective ion-plasma coating based on Cr–CrN after holding in the furnace of a biofuel boiler for 1000 h showed that the abrasive resistance at a steady speed increased by at least 2.5 times compared to samples without coating. According to the results of metallographic, corrosion, and abrasive studies, Cr–CrN-based ion-plasma coating is promising for the protection of pipe surfaces of biofuel boilers exposed to corrosion and abrasive effects of alkali metal salts and ash particles at high temperatures and variable load. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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