Erosive wear of boiler steels by sand and ash

Abstract

Erosive wear of four boilers steels: 16Mo3, P265GH, P91 and 304L, was examined using a four-channel centrifugal erosion tester, two types of sands and one type of ash as the erodant, the particle velocities of 10 and 20ms−1 and the impact angles of 30°, 45° and 90°. The erodants varied in terms of abrasivity, which may be explained by their different composition, shape and size. Concerning the sands, abrasivity and erosivity went hand in hand, with impacts by angular and only silicon- and oxygen-containing Sand 1 causing essentially more material losses than those by Sand 2. Furthermore, because steady-state erosive wear was reached in the tests conducted with the sands, correlation between the extent of erosion and particle velocity could be established, enabling the deduction of the wear coefficient K and exponent n. Among the studied boiler steels, wear coefficient K was the highest for the grade P265GH, suggesting the greatest efficiency of material removal by the particle impacts. When the ash was used as an erodant, steady-state erosion was not reached and abrasivity and erosivity of the particles did not exhibit clear correlation. These results are presented and discussed in this paper.