astm b117 pdf

ASTM B117 Overview

ASTM B117, the Salt Spray Corrosion Test, evaluates material resistance to marine and industrial atmospheres. It simulates continuous salt mist exposure, measuring corrosion rate, pitting, and surface degradation. The standard guides protective coating, alloy, and material selection. 2026.000

Historical Development

ASTM B117 originated in the early 1970s as a response to growing concerns over corrosion in marine and industrial environments. The first edition, published in 1978, established a standardized salt spray chamber test to evaluate the durability of paints, coatings, and metal alloys. Over subsequent decades, the standard evolved through revisions in 1982, 1989, 1996, 2003, 2011, and 2018, each iteration refining test parameters such as temperature, spray concentration, and exposure duration. The 1996 revision introduced a dual‑phase test cycle to better mimic real‑world conditions, while the 2011 update incorporated a more rigorous acceptance criterion based on visual inspection and weight loss. In 2018, the standard incorporated a new classification system for coating performance, aligning with ISO 9227:2017. The most recent 2026 edition, released in March, added optional accelerated test modes for high‑risk applications and expanded guidance on data interpretation. Throughout its history, ASTM B117 has been adopted worldwide, influencing regulatory frameworks, industry best practices, and academic research on corrosion mitigation. Its iterative development reflects the dynamic nature of corrosion science and the continuous need for reliable, reproducible testing methods. This evolving standard remains a cornerstone for engineers, manufacturers, and regulators worldwide, ensuring that corrosion-resistant solutions meet stringent performance benchmarks across diverse environmental conditions.

Scope of the Standard

ASTM B117 defines the scope of the salt spray corrosion test, specifying the types of materials, coatings, and substrates that may be evaluated. The standard applies to ferrous and non‑ferrous metals, alloys, and composite materials used in marine, automotive, aerospace, and industrial settings. It outlines the permissible test chamber dimensions, salt concentration (typically 5% NaCl solution), temperature ranges (20–30 °C for standard tests, up to 50 °C for accelerated tests), and exposure cycles (continuous or intermittent). The scope also covers the acceptable specimen preparation methods, surface finish requirements, and the criteria for evaluating corrosion damage, including visual inspection, weight loss, and pitting measurements. Additionally, ASTM B117 addresses the documentation of test conditions, data recording, and reporting formats to ensure reproducibility and comparability across laboratories. The standard’s scope is designed to provide a consistent framework for assessing corrosion resistance, facilitating material selection, coating performance verification, and regulatory compliance in diverse environmental conditions. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Praesent commodo cursus magna, vel scelerisque nisl. Etiam ultricies Vivamus luctus urna sed arcu Cras at massa

Test Procedure Summary

ASTM B117 test procedure involves placing specimens in a sealed chamber with 5% NaCl spray at 20–30 °C. Exposure cycles last 24 h, 48 h, or 72 h, with optional 2‑hour breaks. After exposure, specimens are cleaned, weighed, and inspected for corrosion, pitting, and film integrity Standard. Test

Equipment Requirements

ASTM B117 testing demands a certified salt spray chamber that meets the ASTM standard dimensions and temperature control specifications. The chamber must be equipped with a 5 % NaCl solution reservoir, a spray nozzle array capable of delivering a uniform mist density of 1 g/m²/min, and a temperature‑controlled environment maintaining 20–30 °C throughout the test cycle. The chamber should have a pressure‑regulated inlet to ensure consistent spray coverage and a venting system to prevent condensation buildup. A calibrated hygrometer and thermometer are required to monitor relative humidity and temperature, respectively, and a data‑logging system should record these parameters continuously. Specimen holders must be made of non‑reactive material, such as stainless steel or anodized aluminum, and designed to keep samples flat and evenly exposed. The chamber should include a removable rack system that allows for easy insertion and removal of test specimens while maintaining the spray pattern. For extended testing, a programmable timer or cycle controller is essential to automate exposure periods and rest intervals. Additionally, a safety enclosure with a sealed door and a pressure relief valve is mandatory to protect operators from accidental spray exposure. Proper ventilation and filtration systems must be regularly calibrated and maintained according to the manufacturer’s guidelines to ensure accurate, repeatable results in compliance with ASTM B117. Equipment must be calibrated.!

Sample Preparation Steps

1. Clean the test surface with a neutral detergent solution, rinse with de‑ionized water, and allow to dry at 60 °C for 30 min.
2. Remove all oils, greases, and residues by applying a 70 % isopropyl alcohol wipe; avoid abrasive materials that could scratch the substrate.
3. If the material is coated, verify the coating thickness with a calibrated micrometer; record the value for later comparison.
4. For metallic samples, perform a mild mechanical polish (e.g., 1200 grit) to remove surface oxides, then rinse and dry as in step 1.
5. Apply the protective coating (primer, paint, or electroless layer) according to the manufacturer’s instructions, ensuring uniform thickness and no voids.
6. Allow the coating to cure in a controlled environment (20–25 °C, 50 % RH) for the specified time, typically 24–48 h.
7. Mount the specimen on a non‑reactive holder using a single screw or adhesive that does not interfere with the spray exposure.
8. Label each sample with a unique identifier, test date, and any relevant notes.
9. Store the prepared specimens in a dry, dust‑free area until the test begins.

These steps ensure that specimens are free from contaminants and exhibit uniform coating thickness, providing reliable data for corrosion resistance evaluation. Procedures should be documented in the test log!

Test Cycle Parameters

ASTM B117 defines a cyclic exposure that alternates between a salt‑fog period and a dry period. The standard specifies a 24‑hour cycle: 12 h at 35 °C, 95 % RH with a continuous spray of 5 % NaCl solution, followed by 12 h at 35 °C, 95 % RH without spray. The spray is maintained at a 1 mm droplet size, with a 50 mm distance between the spray nozzle and specimen surface. The cycle repeats until the total exposure time reaches the test duration, typically 48, 72, or 120 h, depending on the material class.

Key parameters:

• Temperature: 35 °C ± 2 °C throughout the cycle.
• Relative Humidity: 95 % ± 5 % during both spray and dry periods.
• Salt Concentration: 5 % NaCl solution (by weight).
• Spray Droplet Size: 1 mm (± 0.2 mm).
• Spray Distance: 50 mm from specimen surface.
• Cycle Length: 24 h (12 h spray + 12 h dry).
• Exposure Duration: 48, 72, or 120 h total.
• Specimen Orientation: Horizontal, with the coated side facing the spray.
• Ventilation: Adequate airflow to prevent condensation buildup.

During the dry period, the specimen is kept in the same chamber to maintain temperature and humidity. After the cycle, specimens are examined for corrosion products, pitting, and coating integrity. The parameters above ensure reproducibility and comparability across laboratories.

Compliance with ASTM B117 requires detailed record‑keeping. Test logs should capture chamber temperature, humidity, spray rate, and any deviations. Photographic evidence of specimen condition before and after exposure is recommended. Documentation facilitates traceability and supports regulatory submissions. Consistent adherence to the specified parameters ensures data integrity and comparability across test facilities. Are reported standard’s guidelines.

Interpretation of Results

Results are assessed by measuring mass loss, pitting depth, and coating integrity. A specimen passes if mass loss stays below the class threshold and no critical pitting is seen. Comparing to controls and benchmarks guides material selection and future now! testing.!

Acceptability Criteria

ASTM B117 establishes quantitative limits for a specimen’s performance in a salt‑spray environment. The primary metric is mass loss per unit area, expressed in milligrams per square centimeter (mg/cm²). The standard lists a maximum permissible loss; exceeding this value indicates unacceptable corrosion. In addition, the test requires a visual inspection for pitting, cracking, or delamination. A specimen is considered acceptable if pitting depth does not exceed 0.5 mm and coating integrity remains intact, with no evidence of blistering or flaking. When the test involves coated materials, the coating’s adhesion is evaluated through a cross‑hatch or pull test; a failure rate above 5 % renders the coating unacceptable. For alloys, the presence of localized corrosion such as hydrogen embrittlement or stress corrosion cracking is disqualifying, even if mass loss is within limits. The standard also mandates that the specimen’s surface finish match the initial condition; a change in roughness greater than 10 % is a red flag. Finally, the test duration is fixed at 120 hours for most applications, but extended cycles (up to 240 hours) are permissible for environments; results must be compared against the same class limits. Any deviation from these criteria requires re‑testing or material redesign. The acceptability decision is documented in a signed test report, which must include all measured values, photographic evidence, the analyst’s interpretation. This rigorous documentation ensures traceability and compliance with industry regulations. Manufacturers must record results for audit and quality assurance daily now!

Applications Across Industries

ASTM B117 is used by automotive, aerospace, marine, construction, and energy sectors to benchmark corrosion resistance of metals, alloys, and protective coatings. In automotive manufacturing, the test validates paint systems and under‑body coatings against highway salt and coastal humidity, ensuring longevity of body panels and chassis components. Aerospace engineers use the standard to assess aluminum and titanium alloys for aircraft skins, landing gear, and structural fasteners that encounter de‑icing salts and high‑altitude humidity. Marine industries rely on ASTM B117 to evaluate hull coatings, propeller shafts, and offshore platform fittings, guaranteeing that protective layers can withstand continuous exposure to saline spray and wave action. Construction firms apply the test to concrete reinforcement steel, architectural cladding, and bridge decks, verifying that corrosion inhibitors and epoxy coatings meet durability requirements under coastal climates. Energy utilities employ the standard to screen corrosion‑resistant alloys for offshore wind turbine towers, subsea pipelines, and oil‑rig equipment, where salt‑fog exposure can accelerate material failure. In electronics, manufacturers test boards for salt‑spray resistance to prevent circuits in humid environments. The data supports research into advanced corrosion‑resistant materials. Regulatory bodies use ASTM B117 data to ensure compliance with environmental and safety regulations. Consequently, ASTM B117 remains a cornerstone for industries where corrosion can compromise safety, performance, and cost, providing a standardized, repeatable method to evaluate material resilience in harsh, salt‑laden atmospheres…

Legal and Regulatory Context

ASTM B117 is a foundational standard that governs corrosion testing for metals, alloys, and coatings exposed to salt spray. The test simulates continuous mist of 5% NaCl solution at 35 °C and 85% relative humidity, cycling between wet and dry periods. Results provide a quantitative measure of corrosion rate, pitting, and surface degradation, enabling engineers to compare material performance under marine or industrial conditions. The standard is referenced in federal regulations such as the Clean Water Act, OSHA safety guidelines, and Coast Guard certification for hull coatings, ensuring that protective systems meet durability requirements. In the oil‑and‑gas sector, the American Petroleum Institute and Offshore Technology Conference mandate ASTM B117 data for subsea pipelines and platform structures, while the European Union’s REACH regulation and the UK Health and Safety Executive incorporate it into coating assessments. Compliance with ASTM B117 is therefore a technical benchmark but also a legal obligation that can affect licensing, insurance, and liability. Failure to meet the test’s criteria can trigger regulatory penalties, higher insurance premiums, or facility shutdowns. Consequently, organizations routinely include ASTM B117 test reports in environmental impact statements, risk‑management plans, and contractual agreements to demonstrate adherence to both national and international legal frameworks across multiple sectors. This standard ensures compliance.

Accessing the ASTM B117 PDF

The ASTM B117 PDF is available through ASTM International’s online store, or university libraries. Purchase or access via the ASTM website, or request through interlibrary loan. Some free previews exist, but full text requires payment or institutional access. Free access granted..

Official ASTM Distribution

ASTM International sells the ASTM B117 standard through its official website and authorized distributors. The standard, titled “Salt Spray Corrosion Test – Procedure and Acceptance Criteria,” is available as a PDF for purchase. Users can download the document after completing a secure checkout, which requires an ASTM account or existing credentials. Many universities and research institutions have institutional subscriptions to the ASTM Digital Library, providing free or discounted access. The PDF contains the full test procedure, equipment, specimen preparation, test cycle parameters, and acceptance criteria. It also includes a revision history and a summary of changes from previous editions. The latest edition, published in 2026, is clearly indicated. For bulk purchases, ASTM offers volume discounts and licensing agreements. The PDF can be printed or stored digitally, and a backup copy is recommended. The ASTM website also provides a Quick Reference guide that highlights key sections for quick consultation during testing. All official ASTM documents are copyrighted; redistribution without permission is prohibited, though excer The PDF also contains figures and tables that aid in interpreting results, and a glossary of terms.

Common Issues and Troubleshooting

Common pitfalls arise when the salt spray chamber is not properly calibrated, leading to inaccurate corrosion rates. Inadequate temperature control or uneven mist distribution can skew results. Improper specimen mounting may cause under‑estimation of corrosion. Residual oils or contaminants on the surface before testing can also cause false positives. The test cycle timing—especially the transition between wet and dry phases—must be strictly followed; deviations can produce inconsistent pitting patterns.

• Verify chamber calibration against a reference standard.
• Inspect and clean spray nozzles regularly.
• Maintain temperature within ±2 °C of the set point.
• Ensure specimens are mounted per the diagram in the standard.
• Clean surfaces with approved solvents before testing.

If pitting appears irregular, verify the spray angle and ensure the chamber is level. Small leaks can create hot spots that accelerate corrosion.

When the test fails to meet the acceptance limits, the first step is to review the test log for any deviations in cycle timing or temperature. If the chamber was not level, the spray may have been uneven, creating localized corrosion. Inspect the specimen for surface contamination; oils or residues can mask true corrosion. Document all observations and corrective actions for audit purposes.

Always record precisely temperature and humidity during the test.

Future Trends and Revisions

ASTM B117, the Salt Spray Corrosion Test, remains a cornerstone for evaluating material durability in marine and industrial settings. Its standardized cycle of 8‑hour wet/4‑hour dry exposure simulates salt‑laden atmospheres, enabling comparison across coatings, alloys, and composites. Recent revisions emphasize digital monitoring, allowing real‑time tracking of mist density, temperature, and humidity, thereby reducing operator variability. The updated standard also introduces a 12‑hour wet/12‑hour dry sequence, aligning with ASTM G48 and ISO 9227 for greater realism. Manufacturers are encouraged to validate new coatings against both the classic 5 % NaCl and a mixed 5 % NaCl/0.5 % Na₂SO₄ solution, ensuring broader protection claims. The revision incorporates a post‑surface analysis requirement, mandating SEM or EDS examination of corrosion products to identify degradation mechanisms. Future updates are likely to focus on automation, integrating machine algorithms to predict long performance from short data. The ASTM committee is also exploring a micro‑climate sub‑test, applying localized temperature and humidity gradients to evaluate coating performance under thermal cycling. Stakeholders call for a revised criterion with a corrosion rate threshold in mils per year.