Properties of thermal sprayed coatings for internal use in pipes and bends
Abstract
NTNU/SINTEF are participating in a research project called Smooth Surfaces , financed by Norsk Forskningsråd, and with Brunvoll, Triplex, Omya Hustadmarmor and Aquamarine as industry partners in the project.
One of the activities in this project is named internal corrosion- and wear protection of pipes by means of thermal spraying .
The objective of this master thesis has been to document main properties for thermal sprayed coatings for internal use in pipes and bends. The main properties in question are; wear resistance, corrosion, hardness, ductility and porosity.
Different methods of thermal spray were evaluated based on specified requirements and High Velocity Oxy-Fuel (HVOF) was selected as the preferred method of applying the coating. As for the coating material itself, Amperit 560 was selected due to its references as a proven material for corrosion and erosion protection of equipment.
Hence, the scope of this master thesis has been to document the properties of the thermal sprayed Amperit 560 coating. The parameters used when thermally spraying the test samples simulates the spraying conditions present when spraying internal surfaces of pipes. Samples thermally sprayed with an angle of 45 and 90 degrees were supplied to compare the quality.
The main requirement of the coating is to provide erosion and corrosion resistance. These properties were documented using an electrochemical porosity test and an erosion test using a water slurry containing alumina. Tests to characterize the mechanical properties of the coating were done as well. These tests includes examination of microstructure and measuring of hardness, roughness and adhesion strength. The behaviour of the coating during bending of the surface and shock impacts is also included.