Erosion-corrosion characteristics of a 2.25Cr-1Mo steel exposed at low particle velocities

The erosion-corrosion characteristics of a 2.25 Cr-1 Mo steel at low particle velocities and elevated temperatures were determined using a nozzle type laboratory erosion tester. The tests were performed with 180-360 mu m angular alumina particles at 60 deg angle of impingement at low particle veloci...

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Bibliographic Details
Published in:Tribology international 1995-03, Vol.28 (2), p.107-117
Main Authors: Engman, U, Olsson, M, Tarkpea, P
Format: Article
Language:English
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Summary:The erosion-corrosion characteristics of a 2.25 Cr-1 Mo steel at low particle velocities and elevated temperatures were determined using a nozzle type laboratory erosion tester. The tests were performed with 180-360 mu m angular alumina particles at 60 deg angle of impingement at low particle velocities of 2.6-8.2 m/s and in the temperature interval 20-600 deg C. The steel was tested both in the as-received condition and in two preoxidized conditions. The erosion-corrosion rate of the steel, both in the as-received and in the preoxidized conditions, was found to increase with increasing particle velocity. In contrast, the wastage rates were relatively independent of temperature in the temperature range investigated, the only exception being specimens exposed to the lowest particle velocity (2.6 m/s) at the very highest temperature, i.e. 600 deg C, which displayed a drastic increase in wastage. Specimens preoxidized at 700 deg C exhibited a somewhat higher erosion rate compared with non-preoxidized specimens and specimens preoxidized at 500 deg C. Microscopy revealed four different major wastage mechanisms, i.e. (i) plastic deformation, cracking and micro chipping of surface material of a size corresponding to the area impinged by eroding particles, (ii) chipping of somewhat larger oxide fragments (up to 10-15 mu m in diameter), (iii) chipping or spalling of relatively large oxide fragments (up to 30-50 mu m in diameter), and (iv) spalling along the steel-oxide interface or within an oxide layer due to cohesive failure, of larger (up to 500 mu m in diameter) oxide layer fragments. In the present study extensive spalling was only observed for non-preoxidized specimens exposed to the lowest particle velocity (2.6 m/s) and the two highest specimen temperatures (550 and 600 deg C).
ISSN:0301-679X