Metallurgy for Erosion & Corrosion
ESSCO pumps has been collecting application information on pumping equipment installed in slurry and grit service since 1976. This information is provided to assist customers in selecting the proper liquid end materials for maximum life in severe duty applications.
Many materials have been studied as well as methods of hardening to increase equipment life. As a result of these studies in general ESSCO has settled on three materials which the greatest number of applications fall into. These materials are "Ni-Hard", HCI (High Chromium Iron) and CD4MCu. Each material has it's own characteristics for abrasion and corrosion resistance. Every application should be considered carefully and the best material selected given a specific application.
Ni-Hard and HCI are considered white cast irons, whereas CD4MCu is considered a Austenitic steel. The white cast irons generally have a higher Brinnell hardness in the "as cast" form. These materials can be heat treated to Brinnell hardness as high as 750. As the Brinnell hardness increases the material becomes more brittle. Often these materials will require stress relieving in order to reduce internal stresses which frequently cause castings to crack while being stored.