Abstract
Development of new arc sprayed iron based coatings for protection against gas abrasive wear at room and elevated temperatures are of the great interest because of permanently increasing pressure to reduce production and repair costs of power production facilities. Two cored wires in steel cover with Fe-Cr-B-Al and Fe-Cr-N-Al filling are proposed as an alternative choice for self fluxing and cermet coatings that are considered nowadays for protection of screen tubes of boilers of power stations that are operated under the temperatures 500-600 °C. Oxidation behaviour of arc sprayed coatings is estimated by gravimetric measurements. Abrasive wear resistance at elevated temperatures after 1 hour is investigated by means of laboratory unit that alloys a rotation of coated specimens in heated quartz sand. It is shown that abrasion wear lost of carbon steel increases 1.5 times when test temperature increases from 20 °C to 550 °C. For all investigated coatings the 20-25% decrease of wear lost is observed at higher temperature. Arc sprayed coatings of both investigated systems improve significally the abrasive wear resistance of carbon steel. At room temperature the improvement by factor 1.3-2.2 times and at the temperature 550 °C by factor 2.7-4.6 is observed depending on chemical composition of coatings.
