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What is a salt spray test?

Firstly, the salt spray test is a technique used to evaluate the corrosion resistance of a material or its coating. Specifically, this test involves exposing material samples to a saline mist, i.e. a vaporized salt solution, so as to create a highly corrosive environment similar to that which occurs in certain environmental conditions.

Why is the salt spray test important when verifying corrosion resistance?

The verification of the corrosion resistance of materials is essential in many industrial sectors, such as automotive, aeronautics, marine, electronics, etc.

In fact, in these sectors, the materials must be able to withstand the environmental stresses and the chemical substances present in the workplace.

That is why, the salt spray test is one of the most utilized methods to verify the corrosion resistance of materials. Thanks to this test, it is therefore possible to evaluate the effectiveness of protective coatings and the durability of products in extreme environmental conditions.

How do salt spray chambers work?

Salt spray chambers are special machines which are used to perform salt spray tests on material samples. These chambers are equipped with systems for dispensing the salt solution diffused in mist form inside the chamber itself.

Futhermore, it is important to note that the chambers are equipped with temperature settings according to the reference standard.

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Description of the equipment used

The equipment used for the salt spray test consists firstly of a test chamber, a salt spray generator, a temperature regulation system and finally a set of material samples to be tested.

The samples are usually small pieces of material which are placed inside the test chamber. Once the test starts, a saline mist is dispensed into the chamber allowing the samples to be exposed to a corrosive environment.

How is salt spray produced?

The salt spray used for the test is produced thanks to a special boiler, which consists of a salt solution tank, which is then heated using an electric resistor.

Futhermore, when the salt solution reaches the boiling temperature,  a vaporized salt solution forms and is fed into the test chamber through a pipe system.

Corrosive environment inside the test chamber

The corrosive environment inside the salt spray test chamber is highly aggressive and simulates an environment which aims to test the corrosion resistance of materials and products. The salt spray produced inside the test chamber creates a condition of high humidity with the presence of chlorides, which are the main causes of corrosion.

Sea Air Simulation

An example of a corrosive environment similar to that created inside the test chamber is sea air.  Salty sea air is known for its ability to damage metallic materials and corrode components exposed to the elements.  Sea air is a mixture of seawater and aerosols, which contain a significant amount of chlorides and other highly reactive ions.

As shown in the images below and thanks to artificial intelligence, we can see how boats are corroded by salty sea air, for instance.

More examples of simulated corrosive environments

Other examples of corrosive environments may include industrial wastewater, acidic or alkaline solutions, dusts containing aggressive chemicals, exhaust gases, liquids containing chlorides and other environmental pollutants.  What’s more, all of these environments can cause corrosion of materials and products, causing damage and malfunctions.

Therefore, the salt spray test is an extremely effective method for verifying the corrosion resistance of products and materials before they are sold on the market.

The saline solution used for creating a corrosive environment

As previously mentioned, a fundamental element of the test is the saline solution.

This is prepared to reproduce the environmental conditions in which the product will be used. This way, it’s possible to simulate the conditions of the product when exposed to corrosion.

Type of saline solution used

The saline solution used for the test is generally 5% sodium chloride (NaCl) dissolved in demineralised water with a neutral PH value. However, depending on the specific applications, solutions of mixed chlorides or other substances, such as copper sulphate, may be used.  It depends on the type of corrosive environment to which the product will be exposed.

Within the chamber, the saline solution spray produces a dense fog which deposits on the surface of the samples, imitating the exposure of the product to aggressive environmental conditions.

Salt spray test applications

During an in-depth study on salt sprays, we carried out a LinkedIn survey to find out how many professionals in the sector have actually used this method.

The results of the poll, which can be seen below, show an interesting overview of the use of this quality control technique among platform subscribers.

The purpose of the survey was to better understand how widespread the use of the salt spray chamber is among quality control professionals and which sectors benefit the most from it. In the end, the data collected revealed that a large number of subscribers had direct or indirect experience with this test methodology, confirming its importance as a corrosion resistance assessment tool.

Moreover, the participants shared their experiences and specific applications in their respective industries, highlighting the versatility and effectiveness of this tool.

Industries where the salt spray chamber is used

Based on the comments and responses from our poll, we’ve identified some of the most common uses of the salt spray chamber:

  • Automotive: Used to test the corrosion resistance of metal parts and coatings used in vehicles, such as engine components, exhaust systems and body parts.
  • Electronics:  Used to evaluate the corrosion resistance of circuit boards, connectors, and metal enclosures in electronic and telecommunications devices.
  • Naval sector: Used to check the durability of materials and coatings used in the construction of boats and port infrastructures, exposed to extreme salt-based conditions.
  • Construction: Used to test the corrosion resistance of fasteners, metal structures and protective coatings used in buildings and in bridge construction.
  • Aerospace: Used to check the corrosion resistance of metallic components and coatings used in aircraft and aircraft engine manufacturing.
  • Other sectors.

Why choose the SAMA Tools name-brand salt spray chamber?

Our customers have purchased SAMA Tools name-brand salt spray chamber for several reasons:

Quality: Our chambers are subject to strict quality controls during production.
Experienced Technicians: Our experienced engineers conduct on-site surveys prior to chamber shipment to ensure that all customer requirements are met and that the chamber is suitable for the specific application.
After-sales service: We offer a complete after-sales service to meet customer needs in case of problems or maintenance requests.
Multiple applications: The SAMA Tools name-brand salt spray chamber can be used in various industrial sectors, such as automotive, aeronautical and naval industries.

Don’t miss this opportunity to protect your products from corrosion and ensure maximum durability over time.  Contact us now to evaluate the purchase of your SAMA Tools salt spray chamber with us and find out how our experienced technicians can assist you in choosing the right model for your needs.

What is the salt spray test?

 

The salt spray test is a standardized test method used to check corrosion resistance of coated samples.

During the salt spray test, an accelerated corrosive attack is produced in order to predict the coated samples suitability in use as a protective finish.

Salt spray tests are generally employed to produce rapid comparisons between expected and real corrosion resistance.

 

 

Salt spray test

How the test works?

Tests are carried out in a closed testing chamber.

A salt-water solution is applied to a sample through a spray nozzle.

This produces a corrosive environment of dense saline fog to emulate a corrosive experiment.

The appearance of corrosion products (oxides) is evaluated after a period.

The more corrosion resistant the coating is the longer will be the period in testing without showing signs of corrosion.

Tests can take between 24 and over 1000 hours for certain coatings.

 

 

Salt spray test

[Video] Salt spray test to check corrosion resistance

 

Which is the UNI reference standard?

The reference standard is UNI EN ISO 9227: 2006: Corrosion tests in artificial atmospheres – Salt fog tests.

It defines the equipment, reagents and procedures that must be used to perform the tests in neutral salt spray (NSS), salt spray-acetic (AASS) and cupro acetic salt spray (CASS).

The aim is to evaluate the corrosion resistance of metallic materials, with or without permanent or temporary anti-corrosive protections.

The standard does not indicate the duration of the salt spray tests since it is indicated by the product standards.

 

 

 

Salt spray test

Why a salt spray cabin is so useful?

The resistance results of a material or coating to corrosion in a salt spray test is useful to determine the strength of a particular fastener or coating for the purpose of your production needs.

Watch the salt spray cabin test!