Rust Preventive Formulators

ASTM B117 is a widely recognized standard test method for evaluating the corrosion resistance of materials, particularly coatings and rust preventive oils, when exposed to a salt spray environment. This test is often referred to as the “Salt Spray Test” and is used to simulate the effects of harsh, corrosive conditions on materials. Here are the details of the test:

Test Objective: The main purpose of the ASTM B117 test is to determine the ability of a rust preventive oil or coating to protect a substrate from corrosion when subjected to a controlled salt spray environment. The test provides a way to compare the corrosion resistance of different materials and assess their suitability for various applications.

Test Apparatus: The test is typically conducted in a salt spray chamber, also known as a salt fog chamber. The chamber provides controlled conditions of temperature, humidity, and salt concentration to accelerate the corrosion process. The specifics of the apparatus, such as chamber size and construction, should adhere to the requirements outlined in ASTM B117.

Test Procedure:

1. Preparation of Specimens: The specimens or samples to be tested are cleaned thoroughly to remove any contaminants that might affect the test results. The surface preparation should mimic real-world conditions as closely as possible.
2. Application of Rust Preventive Oil: If the objective is to test rust preventive oils, the oil is applied to the specimens according to the manufacturer’s instructions or as specified in the testing protocol.
3. Exposure to Salt Spray: The specimens are then placed inside the salt spray chamber. The chamber is filled with a solution of sodium chloride (salt) dissolved in water. The solution is atomized to create a fine mist or fog of salt-laden water droplets. The specimens are exposed to this salt-laden environment for a predetermined period.
4. Controlled Conditions: The test conditions are carefully controlled. The temperature, humidity, and salt concentration are maintained within specified ranges throughout the test duration.
5. Test Duration: The test duration can vary depending on the material being tested and the intended application. Common test durations are 24, 48, or 96 hours.
6. Evaluation: After the exposure period, the specimens are removed from the salt spray chamber. They are inspected visually for signs of corrosion, such as rust formation, blistering, or coating deterioration. The level of corrosion is typically rated using standardized scales, which may vary depending on the type of material being tested.

Test Result Interpretation: The results of the ASTM B117 test are used to evaluate the corrosion resistance of rust preventive oils or coatings. The extent and nature of corrosion on the specimens help determine the effectiveness of the material in protecting against corrosive environments. It’s important to note that the test provides an accelerated simulation of corrosion and may not precisely replicate real-world conditions.

Limitations: While the ASTM B117 test is a valuable tool for comparing materials’ corrosion resistance, it’s essential to recognize its limitations. The test doesn’t perfectly replicate all real-world environmental conditions, so results should be interpreted with consideration for the specific application and conditions the material will face.

In conclusion, the ASTM B117 salt spray test is an established method for evaluating the corrosion resistance of rust preventive oils and coatings. It plays a crucial role in quality control, material selection, and research and development for products that need to withstand corrosive environments.

ASTM D1748 is a standardized test method developed by the American Society for Testing and Materials (ASTM) to determine the corrosion preventive properties of rust preventive oils. This method is specifically designed to evaluate the effectiveness of these oils in protecting metal surfaces from corrosion under conditions of high humidity. The test is commonly referred to as the “Humidity Cabinet Test.”

Test Objective: The primary objective of the Humidity Cabinet Test (ASTM D1748) is to assess the ability of rust preventive oils to prevent corrosion on metal surfaces subjected to high humidity conditions. This test helps manufacturers, researchers, and quality control personnel in the petroleum and industrial sectors determine the suitability and performance of rust preventive oils in protecting various metal components from corrosion during storage and transport.

Test Procedure: The test involves exposing metal panels to controlled conditions of high humidity while coated with the rust preventive oil being evaluated. The procedure typically involves the following steps:

1. Preparation of Metal Panels: Clean and prepare the metal panels, usually made of steel or other relevant materials, by removing any pre-existing rust, dirt, or contaminants.
2. Application of Rust Preventive Oil: Apply a uniform coating of the rust preventive oil to the metal panels using a suitable method (brushing, spraying, dipping, etc.). Ensure that the oil is applied according to manufacturer specifications or as required by the testing protocol.
3. Placement in the Humidity Cabinet: Place the coated metal panels in a humidity cabinet that is capable of maintaining a specific high humidity environment (often around 95% relative humidity) at a controlled temperature.
4. Exposure Period: Allow the coated panels to remain inside the humidity cabinet for a predetermined period, which may vary based on the specific requirements of the test or industry standards.
5. Evaluation: At the end of the exposure period, remove the metal panels from the humidity cabinet. Inspect the panels for any signs of corrosion, such as rust formation or discoloration. Assess the extent and severity of corrosion according to predetermined criteria.
6. Report Generation: Document the results of the test, including the duration of exposure, any visible signs of corrosion, and other relevant observations. This information can be used to evaluate the performance of the rust preventive oil.

Interpretation of Results: The performance of the rust preventive oil is assessed based on the extent and severity of corrosion observed on the coated metal panels after exposure to the high humidity environment. The less corrosion observed, the more effective the rust preventive oil is considered to be.

Significance: The Humidity Cabinet Test (ASTM D1748) is valuable for quality control and product development purposes in industries where rust preventive oils are used to protect metal components from corrosion during storage, transportation, and other stages of their lifecycle. It provides insight into the ability of these oils to withstand high humidity conditions and prevent the onset of corrosion.

Limitations: It’s important to note that while the Humidity Cabinet Test can simulate high humidity conditions, it may not fully replicate real-world scenarios that components might encounter. Additionally, the test focuses solely on the performance of rust preventive oils under high humidity, and other factors that contribute to corrosion prevention (such as exposure to other corrosive agents) are not directly evaluated by this test alone.

Overall, the ASTM D1748 Humidity Cabinet Test serves as an essential tool for evaluating the corrosion protection capabilities of rust preventive oils, aiding industries in selecting effective products for their specific applications.

The Stack Stain test is a standardized method used to evaluate the anti-staining properties of oils and lubricants. This test helps determine the ability of an oil or lubricant to protect metal surfaces from stain formation when exposed to humid conditions. The test is particularly relevant for metal parts and components that may be stacked on one another during storage or used in environments where moisture is a significant concern.

Industries such as marine, automotive, and manufacturing often operate in humid, wet, or water-rich conditions. Rust preventive oils with excellent dewatering and demulsibility capabilities are better suited for these environments.

The demulsibility test evaluates the ability of a rust preventive oil to separate from water and emulsions, which are mixtures of oil and water. In this test, the rust preventive oil is mixed with water to create an emulsion. The time it takes for the oil to separate and rise to the top is measured, indicating the oil’s demulsibility characteristics.