Corrosion Test for Engine Coolants Tester

Evaluating Engine Coolant Corrosion Resistance with the Corrosion Test for Engine Coolants Tester

Introduction

Engine coolants not only must protect against freeze-thaw damage but also prevent corrosion of critical engine components—aluminum heads, cast iron blocks, brass radiators, and solder joints. The Corrosion Test for Engine Coolants Tester from Changsha Friend Experimental Analysis Instrument Co., Ltd. provides a controlled environment to quantify metal corrosion rates in various coolant formulations, enabling formulators and end-users to ensure long-term engine protection.

Rationale for Corrosion Testing

Corrosion in cooling systems can lead to pitting, gasket leaks, radiator tube blockages, and decreased heat-transfer efficiency. The corrosion rate depends on coolant composition (glycol concentration, inhibitor type), pH, temperature, and contaminants. By simulating accelerated conditions, laboratories can:

• Benchmark candidate coolant formulations.

• Verify OEM or global specification compliance (e.g., ASTM D1384, ASTM D2809).

• Determine optimal refilling or replacement intervals.

• Screen alternative corrosion inhibitors or formulations.

Testing Methodologies

The instrument typically supports two standardized procedures:

1. Static Corrosion Test (ASTM D1384)

• Small metal panels or coupons (copper, brass, steel, cast iron, solder) are suspended in sealed bottles containing coolant.

• The test is conducted at 100 °C for a specified period (e.g., 100 hours).

• After exposure, coupons are cleaned, dried, and weighed to determine mass loss (in mg/cm²).

2. Dynamic Corrosion Test (ASTM D2809)

• Simulates coolant flow by circulating fluid through a loop containing metal specimens mounted on a rotating wheel or within a flow cell.

• Test temperature is maintained at 90–95 °C for 100 hours, and mass loss is measured post-test.

Instrument Design Highlights

• Temperature-Controlled Bath or Circulator: Holds coolant at ±0.5 °C stability during static or dynamic tests.

• Test Coupon Fixture: Allows easy insertion and removal of multiple metal strips; ensures consistent exposure area.

• Circulation Pump and Flow-Cell Module: For dynamic tests, a low-shear pump circulates coolant at controlled flow rates (e.g., 1 L/min).

• Automated Data Logging: Records temperature, pH (optional), and elapsed time; integrated digital balance compatibility simplifies mass tracking.

• pH Monitoring and Adjustment: Optional pH probe and dosing pump maintain target pH (e.g., 7.5–8.5) during extended tests.

Applications

• Coolant Formulators: Accelerated screening of new inhibitor chemistries (organic acids, nitrites, silicates).

• Automotive OEMs: Validate that coolant meets industry standards for multimetal compatibility.

• Heavy-Duty Engine Manufacturers: Assess coolant performance under high heat rejection and contaminant levels.

• Maintenance Providers: Verify in-service coolant still provides adequate corrosion protection, guiding flush intervals.

Best Practices

1. Coupon Preparation: Polish coupons to a uniform surface finish (e.g., 600 grit) and degrease with solvent to remove machining oils.

2. Coolant Conditioning: Preheat coolant to test temperature, adjust pH to target range, and degas to eliminate dissolved air that can accelerate erosion.

3. Mass Loss Calculation: After test, immerse coupons in inhibitor-free acid solution (per standard) to remove surface oxides, rinse in deionized water, dry in an oven at 60 °C, and weigh.

4. Replication and Controls: Include blank coupons (in deionized water) and reference coolant samples in each run to validate method consistency.

5. Data Interpretation: Express corrosion rates as mg/cm² × 100 hours⁻¹ and compare against specification maximums (e.g., < 0.1 mg/cm²).

By integrating this Corrosion Test for Engine Coolants Tester into laboratory protocols, organizations can optimize coolant chemistries, prevent premature engine wear, and maintain reliable heat-transfer performance.