Journal Published Online: 13 December 2018
Volume 7, Issue 1

Energy-Based Water Droplet Impact Erosion Studies of Laser-Treated Austenitic and Martensitic Steels and their Applications

CODEN: MPCACD

Abstract

High-power diode laser (HPDL) surface treatments of high-manganese austenitic and high-chromium martensitic steel round specimens have been carried out, and their resistance to water droplet impact erosion (WDIE) in air was evaluated as per ASTM G73-10, Standard Test Method for Liquid Impingement Erosion Using Rotating Apparatus. This is because the water droplets always travel along with a fluid medium, either steam or air, and these are influenced by inertial, Coriolis, and centrifugal forces, which are missing in a vacuum. Because of these forces, the water droplets elongate and may break before hitting a target, resulting in WDIE damages entirely different from those in a vacuum. The WDIE damages on the test specimens were observed on the leading edge towards the suction side, where the boundary layer is attached, and the pressure gradients are high. These are similar to those occurring on the blades of an axial flow compressor of a gas turbine, a low-pressure steam turbine, and a helicopter rotor, because their leading edges are round. The WDIE testing is based on water droplet kinetic energy (KEd) and kinetic energy flux (KEfd). It has been proved experimentally that the product of KEd and KEfd can predict WDIE damages in a material, and this product can be used to compare the WDIE test results of different materials received from different laboratories. It is observed from the test results that the resistance to WDIE of HPDL-treated high-manganese austenitic steel (Hadfield’s steel) has reduced drastically, whereas that of high-chromium martensitic stainless steel has improved manifold. Fine microstructure and increased martensitic contents in high-chromium martensitic stainless steel after HPDL treatment are the main reasons for its improved performance, whereas the coarse microstructure having microcracks in HPDL-treated Hadfield’s steel is responsible for poor performance.

Author Information

Mann, B. S.
Bharat Heavy Electricals Ltd. Research and Development, Vikasnagar, Hyderabad, India
Pages: 17
Price: $25.00
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Stock #: MPC20180119
ISSN: 2379-1365
DOI: 10.1520/MPC20180119