30° Erosion Test Service

30° Erosion Test Service – Accredited ISO/IEC 17025 Solid Particle Erosion Resistance Assessment for the Croatian Market

The 30° erosion test is a specialized solid particle impingement test used to evaluate the resistance of materials, coatings, and components to the erosive wear caused by solid particles striking a surface at a 30° impact angle. This test is critical for industries where components are exposed to erosive media, including oil and gas pipelines, mining equipment, power generation turbines, hydraulic systems, aerospace components, and slurry handling systems. The 30° impact angle represents a typical condition where both cutting and deformation wear mechanisms are active, providing a realistic assessment of material performance under erosive conditions. In the Croatian market, where the Hrvatski zavod za norme (HZN), the Ministarstvo gospodarstva i održivog razvoja, the Državni inspektorat, the Agencija za zaštitu okoliša (AZO), and the Carinska uprava enforce strict quality, safety, and environmental standards aligned with EU directives and HRN EN (Croatian standards based on European norms), the accurate evaluation of erosion resistance is essential for product certification, material selection, supplier qualification, quality control in manufacturing, and import‑export processes. Our laboratory offers a comprehensive 30° erosion testing service, applying standardized methods such as ASTM G76, ASTM G73, and ISO 15156 to measure the erosion rate, the erosion mechanism, and the resistance of materials to solid particle impingement under controlled test conditions. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Croatian authorities and notified bodies, making them indispensable for regulatory compliance, material validation, and market access in Croatia and the European Union.

Erosion Test Samples and Materials We Regularly Examine

Our laboratory receives a wide variety of materials, coatings, and components for 30° erosion testing. Typical samples include:

• Metals and alloys – carbon steels, stainless steels, aluminum alloys, titanium alloys, nickel‑based superalloys, and hardfacing materials.
• Ceramic and cermet materials – alumina, zirconia, silicon carbide, tungsten carbide, and chromium carbide coatings.
• Polymer and composite materials – fiber‑reinforced composites, elastomers, and thermoplastic coatings.
• Protective coatings and surface treatments – thermal spray coatings, PVD/CVD coatings, galvanized coatings, and organic coatings.
• Prototype and new material formulations – submitted by manufacturers for validation of erosion resistance before series production.
• Field‑retrieved components – for failure analysis and remaining life assessment.

Solid Particle Erosion Testing – 30° Impingement Method

The 30° erosion test exposes a test specimen to a stream of solid particles (typically silica sand, alumina, or other abrasive media) directed at the surface at a 30° angle. The mass loss of the specimen and the erosion rate are measured, providing a quantitative measure of the material's resistance to erosive wear. Our procedures follow international standards and the requirements of the Croatian industrial, energy, and manufacturing sectors.

• 30° erosion test – gas‑jet method (ASTM G76 / NTC 5800 – for materials and coatings) – we use a gas‑jet erosion tester with a nozzle diameter of 1.5 mm to 2.5 mm, directed at the test specimen at a 30° angle. The abrasive particles (e.g., 50 μm to 200 μm alumina or silica sand) are accelerated to a specified velocity (typically 30 m/s to 100 m/s) by a carrier gas (air or nitrogen). The test is performed at a specified temperature (e.g., 23 °C, 100 °C, or 300 °C) for a specified test duration (e.g., 10 minutes to 60 minutes). The specimen is weighed before and after the test, and the mass loss (in mg) is measured. We report the erosion rate (in mg/g of abrasive or in mm³/kg), the mass loss, and the erosion mechanism (based on SEM analysis).
• 30° erosion test – slurry‑jet method (ASTM G73 / NTC 5801 – for liquid‑borne particles) – for components exposed to slurries (e.g., in mining or hydraulic systems), we perform the erosion test using a slurry‑jet tester, where the abrasive particles are suspended in a liquid (e.g., water or oil) and impinged on the specimen at a 30° angle. The mass loss and the erosion rate are measured. We report the erosion rate (in mg/h or mm³/h) and the effect of the slurry composition.
• Erosion test at different impact velocities (NTC 5802 – for the velocity‑erosion relationship) – we perform the erosion test at different particle velocities (e.g., 30 m/s, 50 m/s, 80 m/s, 100 m/s) to construct the erosion rate vs. velocity curve. The velocity exponent (n) is determined. We report the erosion rate at each velocity and the velocity exponent.
• Erosion test at different particle sizes (NTC 5803 – for the particle size effect) – we perform the erosion test with different abrasive particle sizes (e.g., 50 μm, 100 μm, 200 μm) to evaluate the effect of the particle size on the erosion rate. We report the erosion rate for each particle size.
• Erosion test at elevated temperatures (NTC 5804 – for high‑temperature applications) – we perform the erosion test at elevated temperatures (e.g., 100 °C, 300 °C, 600 °C) using a heated test fixture, to evaluate the effect of temperature on the erosion resistance. We report the erosion rate at the elevated temperature and the temperature derating factor.

Erosion Mechanism Analysis – Understanding the Wear Mechanisms

To fully understand the erosion behavior and to identify the dominant wear mechanisms, we perform a detailed analysis of the eroded surface and the wear debris. This analysis is essential for the optimization of the material selection and for the development of erosion‑resistant coatings and surface treatments.

• Scanning electron microscopy (SEM) of eroded surfaces – ASTM E1508 / NTC 5810 – for the wear mechanism analysis – we examine the eroded surface of the specimen using SEM to identify the wear mechanism (e.g., cutting wear, deformation wear, brittle fracture, or a combination of these). The morphology of the wear scars, the presence of ploughing, and the formation of lips and chips are observed. We report the SEM images and the wear mechanism classification.
• Wear debris analysis (NTC 5811 – for the characterization of the removed material) – we collect and analyze the wear debris (the particles removed from the surface) using optical microscopy and SEM. The size, the shape, and the composition of the debris are determined. We report the debris morphology and the composition.
• Cross‑section analysis (NTC 5812 – for the evaluation of the subsurface damage) – we prepare a cross‑section of the eroded specimen and examine the subsurface for the presence of micro‑cracks, deformation zones, and phase changes. The depth of the damage (in μm) is measured. We report the cross‑section images and the damage depth.
• Hardness and microhardness mapping (NTC 5813 – for the evaluation of the work hardening) – we measure the microhardness (Vickers) of the eroded surface and the subsurface to detect any work hardening or softening caused by the particle impact. The hardness profile is plotted. We report the hardness profile and the change in hardness.
• X‑ray diffraction (XRD) – ASTM E1857 / NTC 5814 – for the phase analysis – we use XRD to analyze the eroded surface for any phase transformations (e.g., the formation of martensite, the decomposition of carbides, or the formation of oxides). The phase identification helps to understand the erosion mechanism. We report the phases present and the changes.

Erosion Resistance Correlation with Material Properties – Hardness, Toughness, and Microstructure

The erosion resistance of a material is influenced by its hardness, toughness, and microstructure. Our tests correlate the erosion rate with the mechanical and microstructural properties of the material, providing a comprehensive understanding of the factors that control the erosion behavior and guiding the selection of erosion‑resistant materials.

• Correlation with hardness (NTC 5820 – for the hardness‑erosion relationship) – we measure the hardness (Rockwell, Vickers, or Brinell) of the specimen before the erosion test and correlate it with the erosion rate. The hardness‑erosion relationship is plotted. We report the hardness, the erosion rate, and the correlation coefficient.
• Correlation with fracture toughness (NTC 5821 – for the toughness‑erosion relationship) – we measure the fracture toughness (K_IC) of the specimen (using a standard fracture toughness test) and correlate it with the erosion rate. The toughness‑erosion relationship is plotted. We report the K_IC, the erosion rate, and the correlation coefficient.
• Correlation with microstructure (NTC 5822 – for the grain size and the phase distribution) – we examine the microstructure (the grain size, the phase distribution, and the inclusion content) of the specimen using optical microscopy and SEM, and we correlate the microstructure with the erosion rate. We report the microstructure, the erosion rate, and the correlation.
• Correlation with coating hardness and adhesion (NTC 5823 – for the coated materials) – for coated specimens, we measure the coating hardness (using microhardness) and the coating adhesion (using a pull‑off or a scratch test), and we correlate these properties with the erosion rate. We report the coating hardness, the adhesion strength, and the erosion rate.
• Erosion resistance ranking (NTC 5824 – for the comparative evaluation of materials) – we perform erosion tests on multiple materials (or coatings) under the same test conditions and rank them according to their erosion rates. The ranking is used for the selection of the most erosion‑resistant material for the application. We report the erosion rates and the ranking.

Environmental and Temperature Effects – Simulating Real‑World Service Conditions

The erosion behavior of materials can be significantly affected by the temperature, the presence of corrosive media, and the humidity. Our environmental and temperature effect tests simulate the actual service conditions, providing a realistic assessment of the erosion resistance for the Croatian energy, mining, and industrial sectors.

• High‑temperature erosion test (NTC 5830 – for power generation and gas turbine applications) – we perform the erosion test at elevated temperatures (e.g., 300 °C, 600 °C, 800 °C) to simulate the conditions in gas turbines, boilers, and high‑temperature process equipment. We report the erosion rate at the elevated temperature and the temperature derating factor.
• Corrosive‑erosive test (NTC 5831 – for the combined effect of corrosion and erosion) – we perform the erosion test in a corrosive environment (e.g., with a salt spray, with an acidic solution, or with a corrosive gas) to simulate the combined effect of corrosion and erosion, which is common in marine and chemical plant applications. We report the erosion‑corrosion rate and the synergistic effect.
• Erosion test in a humid environment (NTC 5832 – for the effect of moisture) – we perform the erosion test in a controlled humidity environment (e.g., 50 % RH, 90 % RH) to evaluate the effect of moisture on the erosion mechanism (e.g., the change in the particle adhesion or the corrosion of the surface). We report the erosion rate at each humidity level.
• Erosion test with different abrasive materials (NTC 5833 – for the effect of the particle composition) – we perform the erosion test with different abrasive materials (e.g., silica sand, alumina, glass beads, or coal ash) to evaluate the effect of the particle composition on the erosion rate. We report the erosion rate for each abrasive type.
• Erosion test at different impingement angles (NTC 5834 – for the angular dependence) – we perform the erosion test at multiple impingement angles (e.g., 15°, 30°, 45°, 60°, 90°) to determine the angular dependence of the erosion and to identify the transition angle (the angle at which the erosion mechanism changes). The erosion rate vs. angle curve is plotted. We report the erosion rate at each angle and the transition angle.

Complementary Tests – Coating Adhesion, Porosity, and Surface Finish for Erosion Prediction

To fully understand the erosion resistance of coated materials and to improve the design of erosion‑resistant systems, we perform complementary tests on the coating adhesion, the porosity, and the surface finish. These tests help to predict the erosion behavior and to guide the selection of the optimal coating and surface treatment.

• Coating adhesion test (ASTM D4541 / ISO 4624 / NTC 5840 – pull‑off adhesion test) – we measure the pull‑off strength (in MPa) of the coating (or the surface treatment) to evaluate its adhesion to the substrate. A high adhesion strength is essential for good erosion resistance. We report the pull‑off strength and the failure mode.
• Coating porosity measurement (NTC 5841 – by dye penetration or electrochemical methods) – we evaluate the porosity of the coating (the presence of pores, pinholes, or other defects) that can act as initiation sites for erosion. We report the porosity rating and the defect density.
• Surface roughness measurement (ASTM D7127 / NTC 5842 – for the effect of the surface finish) – we measure the surface roughness (Ra, Rz) of the specimen before the erosion test, and we correlate it with the erosion rate. A rougher surface can increase the erosion rate. We report the roughness values and the correlation.
• Coating thickness measurement (ASTM D7091 / NTC 5843 – for the coating thickness) – we measure the thickness of the coating (in μm) using a magnetic or eddy‑current gauge. The thickness is correlated with the erosion resistance. We report the coating thickness and the uniformity.
• Microstructural analysis of the coating (SEM and EDS – NTC 5844 – for the defect detection) – we use SEM and EDS to examine the coating microstructure, to detect any defects (cracks, voids, or inclusions) that could affect the erosion resistance. We report the SEM images, the EDS spectra, and the defect analysis.

Test Report and Recognition in the Croatian Industrial and Energy Sector

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (erosion testers, balances, SEM, XRD, etc.) and traceability to international standards (NIST, PTB). Our test reports are issued in English (with a Croatian summary available on request) and include:

• Full identification of the test specimen (material, coating, manufacturer, lot number, and dimensions).
• Detailed description of the test methods applied (ASTM/ISO/NTC standards, test conditions, abrasive type, velocity, temperature, and duration).
• Numerical results: erosion rate (mg/g or mm³/kg), mass loss (mg), velocity exponent (n), hardness (HRC/HV), fracture toughness (K_IC, MPa·√m), coating adhesion (MPa), and porosity rating.
• Graphical data: erosion rate vs. velocity curves, erosion rate vs. angle curves, and hardness‑erosion correlation plots.
• Comparative tables against the values specified by the client or against the limits of the relevant standards (ASTM G76, ASTM G73, ISO 15156, and the requirements of the HZN, Ministarstvo gospodarstva, and Državni inspektorat).
• SEM images of the eroded surfaces and the cross‑sections, showing the wear mechanisms and the subsurface damage.
• Recommendations for material selection, coating optimization, and surface treatment to improve the erosion resistance.
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98‑3 Guide.

These reports are fully accepted by the Hrvatski zavod za norme (HZN) for the verification of product conformity, by the Ministarstvo gospodarstva i održivog razvoja for industrial material compliance, by the Državni inspektorat for market surveillance, by the Agencija za zaštitu okoliša (AZO) for environmental compliance, and by the Carinska uprava (Croatian Customs) for tariff classification and quality verification in the import of erosion‑resistant materials and coated components. Additionally, we offer consulting services for the selection of erosion‑resistant materials, the design of protective coatings, and the implementation of erosion monitoring programs, contributing to the safety, reliability, and economic efficiency of industrial operations in the diverse Croatian market, from the power generation and oil and gas sectors to the mining and manufacturing industries.