ASTM B117⁚ Standard Specification
ASTM B117 is a widely recognized standard, designated by its unique identifier. The number following, like B117, indicates the original adoption year or its latest revision.
Designation and Revision Year
The ASTM B117 standard‘s designation includes a letter followed by a number, such as B117, which is crucial for identification. This designation is then followed by a number signifying the year the standard was initially adopted or, if applicable, the year it underwent its most recent revision. This ensures traceability and clarity regarding the specific version of the ASTM B117 standard being referenced. Always refer to the complete designation, including the year, to avoid ambiguity in testing and compliance protocols. Properly citing the revision year is vital for accurate application.
Scope of ASTM B117
ASTM B117 is a standard for salt spray (fog) apparatus. This test is commonly adopted for assessing the relative corrosion resistance of metals and coated metals in a controlled environment.
Purpose of Salt Spray Testing
The primary purpose of salt spray testing, as defined by ASTM B117, is to provide a standardized corrosive environment. This environment is crucial for evaluating the relative corrosion resistance of metallic materials, with or without protective coatings. By exposing specimens to a controlled salt fog, the test accelerates the corrosion process, allowing manufacturers to assess the durability and performance of their products under harsh conditions. The results obtained from the test aid in material selection, quality control, and research and development efforts focused on enhancing corrosion protection.
Referenced Documents
ASTM B117 refers to other essential documents, including ASTM B368, Test Method for Copper-Accelerated Acetic Acid-Salt Spray(Fog) Testing (CASS Test). These documents provide related procedures and standards.
ASTM B368
ASTM B368 outlines the procedure for the Copper-Accelerated Acetic Acid-Salt Spray (CASS) test, an accelerated corrosion test. It’s vital to understand that B368 employs a salt solution with acetic acid and copper chloride to enhance the corrosivity of the salt spray. This method is frequently used to assess the corrosion resistance of decorative chromium plating on steel and zinc-based die castings, offering a quicker alternative to traditional salt spray testing. Careful adherence to ASTM B368 ensures consistent and reliable results when evaluating material performance under corrosive conditions.
Significance and Use
The ASTM B117 standard is significant because it provides a standardized method for evaluating the relative corrosion resistance of materials. This test is widely used across various industries for quality control purposes.
Evaluating Corrosion Resistance
The primary use of ASTM B117 is to evaluate the relative corrosion resistance of metallic materials and coated or uncoated specimens. This standard helps in assessing how materials withstand corrosive environments, offering valuable insights for product development and quality assurance. The test exposes samples to a controlled salt spray environment. Regular inspections during the exposure period allow for the observation and documentation of corrosion initiation and progression. It is important to note that the results are relative and may not directly correlate to real-world performance in all environments. The ASTM B117 offers comparable data.
Apparatus
The ASTM B117 test requires a specific apparatus, most importantly a salt spray chamber. This chamber must meet precise specifications to ensure consistent and reliable testing conditions for evaluating corrosion.
Salt Spray Chamber Requirements
The salt spray chamber used in ASTM B117 must adhere to strict requirements to guarantee uniform and reproducible testing conditions. The chamber’s construction materials should be non-reactive to the salt solution, preventing contamination. Temperature control is crucial, maintaining a consistent environment throughout the test. Proper baffling and air circulation systems are essential for uniform salt fog distribution. The chamber must also include a collection system to measure the rate of salt solution deposition, ensuring it falls within specified limits. Regular calibration and maintenance of the chamber are vital for accurate and reliable corrosion testing results.
Test Specimen Preparation
Proper test specimen preparation is vital in ASTM B117. This involves meticulous cleaning to remove any contaminants. Careful handling is also essential to prevent alterations that could affect test results.
Cleaning and Handling
Prior to salt spray exposure according to ASTM B117, specimens must undergo thorough cleaning; This removes any surface contaminants like dirt, oil, or fingerprints, which could influence corrosion initiation sites and skew the final results. The chosen cleaning method should be appropriate for the material being tested and avoid causing damage or alteration to the surface.
Careful handling procedures are equally crucial. Specimens should be handled with clean gloves or tools to prevent the transfer of contaminants during mounting and placement within the salt spray chamber, ensuring accurate and reliable corrosion resistance assessment.
Salt Solution
The salt solution used in ASTM B117 is crucial. It must adhere to specified concentration levels. This ensures consistent corrosive conditions throughout the test, promoting reliable and comparable results.
Concentration and pH Levels
Maintaining precise concentration and pH levels within the salt solution is paramount for achieving accurate and reproducible test results according to ASTM B117. The salt concentration is carefully controlled to ensure a consistent level of corrosivity throughout the test duration. Similarly, the pH level is meticulously monitored and adjusted to fall within a specified range, preventing deviations that could skew the corrosion process. Adhering to these parameters guarantees uniformity in the testing environment, fostering confidence in the validity and comparability of the obtained data for evaluating corrosion resistance. These meticulous controls are essential for the reliability of ASTM B117.
Procedure
The procedure involves subjecting prepared specimens to a controlled salt spray environment. Key aspects include exposure duration, chamber temperature, and consistent spray application to ensure standardized corrosion testing.
Exposure Duration and Temperature
In ASTM B117, the exposure duration is a critical factor, often measured in hours or days, depending on the expected corrosion resistance of the tested material. The temperature within the salt spray chamber must be maintained consistently, typically at 35°C (95°F), with allowable variations as specified in the standard. Precise control of both these parameters is essential to ensure reproducible and reliable results. Deviations can significantly impact the rate and nature of corrosion, leading to inaccurate assessments of the material’s performance. Careful monitoring and adherence to the specified ranges are therefore vital for valid testing.
Evaluation of Results
The assessment of corrosion is a crucial step. Evaluating the corrosion involves examining the specimens for rust, blisters, or other signs of degradation according to established ASTM standards.
Assessment of Corrosion
The assessment of corrosion following the salt spray test is vital. It involves a detailed examination of the test specimens. This process identifies and quantifies the extent of corrosion. Common indicators include the appearance of rust, blistering, or other forms of surface degradation. Evaluating these changes helps determine the material’s resistance to corrosive environments. Comparing the observed corrosion to established standards ensures objectivity. Such standards provide a benchmark for evaluating the performance of various materials. The goal is to assess suitability for specific applications. Accurate assessment is crucial for predicting long-term durability in real-world conditions and selecting appropriate materials.
Report
A comprehensive report is essential. It must include all relevant data. Detailed observations made during the salt spray test are crucial. This report serves as a record of the material’s performance.
Required Data and Observations
The report must meticulously document all pertinent data gathered during the ASTM B117 salt spray test. This includes the exposure duration, temperature maintained within the salt spray chamber, and the specific type of salt solution used. Accurate recording of pH levels is also necessary. Detailed observations of the test specimen’s condition throughout the duration of the test are also required. It is crucial to note the time and nature of any corrosion initiation, its progression, the types of corrosion observed, and a photographic record. All this information must be included for a complete assessment.
