Rolling Load Testing Service

Rolling Load Testing Service – Accredited ISO/IEC 17025 Mechanical Fatigue and Wear Performance Assessment for the Colombian Market

Rolling load testing is a critical mechanical evaluation method used to assess the durability, fatigue resistance, and wear performance of materials, components, and assemblies subjected to repeated rolling contact stresses. This test simulates the real-world conditions experienced by wheels, tires, rails, bearings, rollers, conveyor systems, and pavement materials in industries such as transportation, mining, construction, material handling, and automotive manufacturing. The ability to withstand rolling loads without excessive wear, deformation, or fatigue cracking is essential for ensuring the safety, reliability, and economic efficiency of equipment and infrastructure. In the Colombian market, where the Superintendencia de Industria y Comercio (SIC), the Ministerio de Transporte, the Ministerio de Minas y Energía (MinMinas), the Agencia Nacional de Hidrocarburos (ANH), and the Dirección de Impuestos y Aduanas Nacionales (DIAN) enforce strict quality, safety, and durability standards for industrial components and infrastructure materials, the accurate evaluation of rolling load resistance is essential for product certification, supplier qualification, quality control in manufacturing, and import-export processes. Our laboratory offers a comprehensive rolling load testing service, applying standardized methods that simulate rolling contact fatigue, abrasion, and deformation under controlled load, speed, and environmental conditions. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Colombian authorities, making them indispensable for regulatory compliance, asset integrity management, and market access in Colombia.

Test Samples and Components We Regularly Examine

Our laboratory receives a wide variety of materials and components for rolling load testing. Typical samples include:

• Wheels and tires – for automotive, railway, mining, and industrial vehicles.
• Railway rails and track components – for freight, passenger, and mining railways.
• Roller bearings and bearing races – for industrial machinery, automotive, and aerospace applications.
• Conveyor rollers and idlers – for bulk material handling and mining.
• Pavement and road materials – asphalt and concrete samples for road construction.
• Industrial rollers and drums – for printing, laminating, and processing machinery.
• Prototype and new material formulations – submitted by manufacturers for validation of rolling load resistance before series production.
• Components retrieved from field service – for failure analysis and remaining life assessment.

Rolling Contact Fatigue Testing – Simulating Repeated Rolling Stress

Rolling contact fatigue (RCF) is the primary failure mechanism in wheels, rails, bearings, and rollers subjected to repeated rolling loads. Our RCF tests simulate the cyclic contact stresses that cause subsurface cracks, spalling, and pitting, and are essential for the certification of railway components and industrial machinery in the Colombian market.

• Rolling contact fatigue test (ASTM E1049 / ISO 1143 / NTC 7800 – for metals and alloys) – a cylindrical test specimen (or a section of a rail or wheel) is mounted in a rolling contact fatigue test rig. A counter-rotating roller applies a cyclic contact stress (in MPa) at a specified load (in kN) and rotation speed (in RPM). The test is run for a specified number of cycles (typically 10⁶ to 10⁷ cycles) or until failure occurs (pitting, spalling, or cracking). The test is performed under dry or lubricated conditions. We report the number of cycles to failure, the contact stress, the wear scar depth (in μm), and the failure mode (pitting, spalling, or cracking).
• Rolling contact fatigue test for railway rails (NTC 7801 – for rail steel) – we use a specialized test rig to simulate the wheel-rail contact, with a test wheel running on a rail specimen. The test is performed under a specified contact pressure (up to 1500 MPa) and a specified number of cycles. We report the fatigue life and the type of damage.
• Rolling contact fatigue test for bearings (ASTM D3702 / NTC 7802 – for bearing steels) – we use a thrust bearing test rig (or a ball-on-rod test) to evaluate the rolling contact fatigue life of bearing steels. The test is performed under a specified load and speed, and the life is measured as the number of cycles to the first signs of pitting. We report the L10 life (the life at which 10 % of the bearings fail).
• Rolling contact fatigue with lubricant contamination (NTC 7803 – for lubrication sensitivity) – we perform the RCF test with contaminated lubricants (e.g., with water or particles) to evaluate the effect of contamination on the fatigue life. We report the fatigue life and the wear rate.
• Rolling contact fatigue at elevated temperature (NTC 7804 – for high-temperature applications) – we perform the RCF test at an elevated temperature (e.g., 100 °C, 150 °C) to evaluate the effect of temperature on the fatigue life. We report the fatigue life at each temperature and the activation energy.

Rolling Abrasion and Wear Testing – Evaluating Material Loss under Rolling Contact

In addition to fatigue, rolling contact causes abrasive wear, which results in the loss of material and the degradation of the component's geometry. Our rolling abrasion tests quantify the wear rate (in mm³/N·m or mm³/cycle) of materials under rolling contact, which is essential for predicting the service life of wheels, rails, rollers, and tires in the Colombian mining and transportation sectors.

• Rolling abrasion test (ASTM G65 / ISO 1996 / NTC 7810 – for metallic materials) – we use a dry sand/rubber wheel abrasion test to simulate the abrasive wear caused by rolling contact with abrasive particles (e.g., sand, mineral dust). The test specimen is pressed against a rotating rubber wheel, and a stream of abrasive sand is introduced. The weight loss is measured, and the wear rate is calculated. We report the wear rate (in mm³/N·m) and the wear scar depth (in mm).
• Rolling abrasion test for elastomers and tires (ASTM D2228 / ISO 4649 / NTC 7811 – for rubber and elastomers) – we use a rotary abrasion test (or a DIN abrasion test) to measure the wear resistance of elastomers under rolling friction. The test specimen is pressed against a rotating abrasive drum. The weight loss and the volume loss are measured. We report the wear rate (in mm³/revolution or mm³/km).
• Rolling abrasion test for pavements (ASTM C131 / NTC 7812 – for aggregate and pavement materials) – we use a Los Angeles abrasion machine (or a micro-Deval apparatus) to evaluate the wear resistance of aggregates and pavement materials under rolling and tumbling action. We report the abrasion loss (in %).
• Rolling wear test under wet conditions (NTC 7813 – for simulating wet environments) – we perform the rolling abrasion test with water or a wet slurry, to simulate the conditions of wet mining and construction operations. We report the wear rate under wet conditions.
• Rolling wear test with varying load (NTC 7814 – for load sensitivity) – we perform the rolling abrasion test at different loads to establish the load-wear relationship. We report the wear rate as a function of the load.

Deformation and Dimensional Stability under Rolling Loads – Evaluating Plastic Flow and Creep

Under rolling loads, materials can undergo plastic deformation, creep, and dimensional changes, which can affect the performance and safety of the component. Our tests evaluate the deformation behavior and the dimensional stability of materials under rolling contact, which is critical for the certification of wheels, rails, and rollers in the Colombian railway and mining sectors.

• • Rolling deformation test (ASTM E290 / NTC 7820 – for metallic materials) – we measure the residual deformation (e.g., the change in diameter, width, or thickness) of the test specimen after a specified number of rolling load cycles. We report the deformation (in mm) and the deformation rate (in mm/cycle).
  • Creep under rolling contact (NTC 7821 – for plastic and elastomeric materials) – we apply a constant rolling load to the specimen for a specified duration (e.g., 100 hours) and measure the time-dependent deformation. We report the creep strain (in %) and the creep rate (in %/hour).
  • Hardness change under rolling load (ASTM E18 / NTC 7822 – for work hardening) – we measure the hardness (Rockwell, Vickers, or Shore) of the specimen before and after the rolling load test, to quantify the work hardening or softening caused by the rolling contact. We report the change in hardness.
  • Surface roughness change under rolling load (NTC 7823 – for wear and deformation) – we measure the surface roughness (Ra, Rz) of the specimen before and after the rolling load test, to quantify the changes in the surface finish. We report the change in roughness.
  • Dimensional stability after rolling load (NTC 7824 – for precision components) – we measure the critical dimensions (e.g., the diameter, the width, the thickness) of the component before and after the rolling load test, to verify that it meets the dimensional tolerances. We report the dimensions and the pass/fail status.

Rolling Impact and Dynamic Load Testing – Simulating Shock and Vibration

In many real-world applications, rolling loads are accompanied by impact and dynamic loads (e.g., from uneven tracks, potholes, or vibrating machinery). Our rolling impact and dynamic load tests simulate these combined effects, providing a more realistic assessment of the component's performance under service conditions. These tests are especially important for mining and off‑road vehicles in Colombia.

• Rolling impact test (NTC 7830 – for wheels and tires) – we drop a weight (or a hammer) onto the rolling specimen (or we apply a sudden load increase) to simulate the impact of a wheel hitting a bump or an obstacle. The impact force (in N) and the resulting deformation are measured. We report the impact force, the deformation, and the condition of the specimen.
• Dynamic rolling load test (NTC 7831 – for variable loads) – we vary the rolling load in a sinusoidal or random pattern (simulating the load variations in a vehicle or a conveyor), and we measure the resulting deformation, wear, and fatigue damage. We report the dynamic response and the service life under dynamic loading.
• Rolling load with vibration (NTC 7832 – for combined stress) – we combine the rolling load with vibration (sinusoidal or random) at a specified frequency and amplitude, and we evaluate the combined effect on wear and fatigue. We report the vibration level and the resulting damage.
• Rolling load at high speed (NTC 7833 – for high-speed applications) – we perform the rolling load test at high rolling speeds (e.g., up to 200 km/h) to simulate the conditions of high-speed trains or automotive wheels. We report the wear rate and the fatigue life at high speed.
• Rolling load with thermal cycling (NTC 7834 – for temperature fluctuations) – we subject the rolling specimen to thermal cycling (e.g., from -10 °C to 60 °C) while applying the rolling load, to simulate the conditions of outdoor and varied climate operation. We report the wear and the fatigue life under thermal cycling.

Complementary Tests – Material Characterization, Microstructure, and Failure Analysis

To fully understand the rolling load performance and to identify the failure mechanisms, we complement the mechanical tests with material characterization, microstructural analysis, and failure analysis. These tests are essential for the certification of materials and for the development of more durable components, and are required by the ANH and the Ministerio de Transporte.

• Metallographic examination (ASTM E3 / NTC 7840 – for metals) – we prepare cross-sections of the specimen and examine the microstructure for the presence of cracks, grain deformation, phase changes, and the depth of the wear-affected zone. We report the microstructural observations.
• Scanning electron microscopy (SEM) and EDS – ASTM E1508 / NTC 7841 – for fracture and wear surface analysis – we use SEM to examine the wear surface and the fracture surfaces to identify the failure mechanisms (e.g., fatigue, abrasive wear, adhesive wear). EDS is used to detect the presence of wear debris or contamination. We report the SEM images and the EDS spectra.
• Hardness and microhardness testing (ASTM E18 / NTC 7842 – for the depth of the wear-affected zone) – we measure the hardness (or microhardness) profile across the wear-affected zone to determine the depth of the work-hardened layer. We report the hardness profile and the depth of the affected zone.
• Residual stress measurement (ASTM E1426 / NTC 7843 – for rolling contact induced stresses) – we use X-ray diffraction (XRD) to measure the residual stress in the specimen after the rolling load test, which is an indicator of the fatigue damage. We report the residual stress values.
• Chemical analysis of wear debris (NTC 7844 – for identifying the wear mechanism) – we collect and analyze the wear debris (particles) from the rolling load test using spectroscopy or SEM-EDS to identify the composition of the wear particles and to infer the dominant wear mechanism. We report the composition and the wear mechanism.

Test Report and Recognition in the Colombian Industrial, Transportation, and Mining Sector

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (rolling contact test rigs, abrasion testers, universal testing machines, etc.) and traceability to international standards (NIST, PTB). Our test reports are issued in Spanish and include:

• Full identification of the test sample (material type, grade, dimensions, manufacturer, and intended application).
• Detailed description of the test methods applied (ASTM/ISO/NTC standards, load, speed, temperature, lubricant, and number of cycles).
• Numerical results: fatigue life (cycles), wear rate (mm³/N·m or mm³/cycle), deformation (mm), hardness change (points HRC/HV), and residual stress (MPa).
• Graphical data: wear vs. cycles curves, fatigue S‑N curves, and hardness profiles.
• Comparative tables against the values specified by the client or against the limits of the NTC 7800 (Rolling contact fatigue), NTC 7810 (Rolling abrasion), NTC 7820 (Deformation), and the requirements of the SIC, Ministerio de Transporte, MinMinas, ANH, and DIAN for industrial components and infrastructure materials.
• Photographs and micrographs (SEM) of the specimen before and after the test, showing the wear scars, cracks, and deformation.
• Recommendations for material selection (e.g., using harder alloys, heat treatment, or coatings), for design improvement (e.g., optimizing the geometry or the lubrication), and for maintenance (e.g., inspection intervals and wear limits).
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98-3 Guide.

These reports are fully accepted by the Superintendencia de Industria y Comercio (SIC) for product registration and quality certification, by the Ministerio de Transporte for the homologation of railway, automotive, and industrial components, by the Ministerio de Minas y Energía (MinMinas) and the Agencia Nacional de Hidrocarburos (ANH) for the validation of materials used in mining, oil, and gas equipment, and by the Dirección de Impuestos y Aduanas Nacionales (DIAN) for tariff classification and quality verification in the import of rolling-contact components and materials. Additionally, we offer consulting services for the selection of wear‑resistant materials, the design of durable rolling-contact systems, and the implementation of predictive maintenance programs, contributing to the safety, reliability, and efficiency of industrial equipment and infrastructure in the diverse and growing Colombian market, from the railway lines and mines of the Andean highlands to the ports and conveyor systems of the Caribbean coast.