Corrosion Systems, Services, and Supplies

There is extensive real-world reliability data, and it’s one of the strongest differentiators of our equipment.

Our chambers are used daily in our accredited corrosion lab, running harsh OEM cyclic tests like GMW 14872 and Ford L-467.

Many customers—including Toyota, Honda, Tesla, Magna, ZF, Denso, Valeo, Bosch, Boeing, and numerous Tier-1 suppliers—run our chambers 24/7.

A significant portion of our installed base has been in service 15–25 years with only routine PM. Legacy Harshaw units from the ’80s and ’90s still operate after simple refurbishment.

The salt spray test (ASTM B117, ISO 9227) exposes materials to a controlled salt fog. It is the most widely recognized accelerated corrosion test.

In the context of ASTM B117, the terms are interchangeable and refer to the same continuous spray environment.

ASTM B117 defines the equipment, solution, temperature, and exposure conditions for valid corrosion testing.

Automotive, aerospace, marine, military, coatings, and industrial labs rely on salt fog chambers for corrosion durability testing.

Typical exposures range from 24–96 hours for coatings screening to more than 1,000 hours for qualification work.

Section 8 of ASTM B117 states that the salt solution shall be prepared as "...5 ± 1 parts by mass of sodium chloride in 95 parts of water..." This requirement is operationalized in Table 1, where Footnote B states that the acceptable solution concentration should be validated by measurement at 25 °C, with an allowable range of 4.0% to 6.0%. The sodium chloride to water ratio and the 4% to 6% range represent the control limits of the practice.

The language referenced in Appendix X1.4, along with Note 10, are informational observations that salt solutions ranging from 2 % to 6 % have been shown to produce similar behavior. They are included to provide information; not to redefine acceptable operating limits. They do not supersede the mandatory requirements in Section 8 and Table 1.

From a compliance standpoint: a salt solution measured below 4.0 % at 25 °C would fall outside the specified operating limits of ASTM B117.

It's important to remember that ASTM B117 is a standard practice, not a material or coating performance specification. Its primary objective is repeatability and consistency of exposure conditions, rather than defining corrosion performance outcomes. ASTM B117 has always acknowledged that perfect uniformity across all laboratories is unattainable, which is why the standard includes flexibility, tolerances, and informational commentary.

ASTM B117 is defined as a Standard Practice for Operating a Salt Spray Apparatus. It is not a coating performance specification. B117 is intended to produce a controlled, repeatable salt fog exposure across a wide range of specimen types, including flat panels, fasteners, and complex geometries. Notably, the non-mandatory appendix explicitly addresses flat test panels, specifying a 30° orientation from vertical.

ASTM B117 differs from coating performance standards in that it establishes a standardized exposure practice while retaining broader orientation allowances to maintain uniformity across diverse specimen geometries. In contrast, coating standards and AMS specifications are material performance specifications. They typically involve flat test panels allowing for tighter specimen angles.

Obviously, the shift from 6° to 15–30° from vertical results in changes in runoff behavior and wetness that can significantly alter corrosion mechanisms. In some cases, the tighter orientations specified in coating standards may intentionally limit sustained wetness to avoid overstressing coatings. The origins and implications of these differing approaches probably warrants a study.

It is also worth noting that positioning specimens outside specified angles would not align with practice or specification requirements.

Note 4 is an informational note describing how dissolved carbon dioxide in water used to prepare the salt solution can influence pH after the solution is atomized. It does not introduce a superseding requirement to Section 8.2, and it is NOT intended to suggest that the user heat the collection solution and allow to cool immediately before measuring the pH.

The language of Note 4 repeatedly refers to the “solution prepared from water saturated with carbon dioxide at room temperature” and to pH adjustment during solution preparation. The three methods described in Note 4 are presented as alternative approaches for managing a CO₂-related pH shift prior to atomization, so that the atomized and collected solution at 35 °C fall within the specified pH limits.

Section 8.2 defines the required salt solution chemistry and references Note 4 for informational purposes. Section 10.2, when addressing atomization and pH measurement of the collected solution, simply refers back to the solution requirements established in Section 8.2 and the explanatory guidance provided in Note 4.

It's important to remember that ASTM B117 is a standard practice, not a material or coating performance specification. Its primary objective is repeatability and consistency of exposure conditions, rather than defining corrosion performance outcomes. ASTM B117 has always acknowledged that perfect uniformity across all laboratories is unattainable, which is why the standard includes flexibility, tolerances, and informational commentary.