Effect of the material surface hardness on the erosion of AISI316

Erosion due to impact of hard and abrasive particles is a common phenomenon observed in many industrial situations. A number of operating variables such as the impact angle and impact velocity affect the erosion process. The rate of erosion is influenced by the relative hardness of the target material and the particles impacting on the surface.In the present work, erosion of austenitic stainless steel has been examined under varying conditions. The hardness of the steel specimens was changed by cold rolling and case hardening of the surface by nitriding. Several specimens having different hardness were prepared using the above techniques. These samples were tested in an air jet impingement tester (as per ASTM G76 standard). Silica sand particles having mean particle size of 100, 145 and 200 μm were used for impingement on the steel surface of varying hardness. The specimens were tested at impact angles varying between 15° and 90° and the impact velocity of the particles was changed between 20 and 32 m/s. The tests were also conducted at specimen temperature varying between the room temperature to 150 °C. The eroded specimens were examined in an electron microscope to study the material removal process. This paper discusses the results of this extensive test program to study the erosive wear behavior of AISI 316 austenitic stainless steel specimens.