Country/Industry/Company of Origin: Japan Automotive

Mazda MES MN 601G  Test Method for Paint Film

Section 27 for this test standard discusses the 5 class requirements for corrosion testing

Class 1 – Salt Spray Test

Class 2 – Perforation Corrosion Resistance Test

Class 3 – Scratch Corrosion Resistance Test

Class 4 – Edge Corrosion Resistance Test

Class 5 – Filiform Corrosion Resistance Test

Class 2 OR Class 3 can be tested to MAZDA MCT-2M which requires a fully enclosed chamber to perform the following test steps:

• 6 hour Salt Spray @ 35°C in accordance with JIS Z 2371
• 3 hours Drying @ 50°C /  20-40%RH
• 14 Hour wetting @ 50°C / 95% RH
• 1 hour standard ambient temperature

The test profile runs for 24 hours

For Class 2 testing this should be ran for 120 cycles

For Class 3 testing this should be ran for 60 cycles

This test can be ran in an Ascott Cyclic Chamber fitted with some accessories

Nissan Engineering Standard – Composite Corrosion Test

NES M-0007 is used to measure the degree of rusting, blistering and adhesion when the specimen is exposed to corrosive conditions such as salt spray, drying and wetting (condensate humidity)

Method B of the standard requires a Cyclic corrosion chamber which can automatically cycle between periods of salt spray, drying and wetting.

Any one of the following cycles below can be chosen to run this test in agreement with the parties concerned

• CCT-1 -Salt Spray (35°C, 4h) → drying (60°C, 2h)→ wetting (50°C, 95% RH, 2h)
• CCT-2- Salt Spray (35°C, 2h) → drying (60°C, 2h)→ wetting (50°C, 95% RH, 4h)
• CCT-4 -Salt Spray (35°C, 10min) → drying (60°C, 155min)→ wetting (60°C, 95% RH, 75min), with a sub-programme of drying (60°C, 160min)→wetting (60°C, 95%RH, 80min) repeated 5 times

See above hyperlinks for further information on each of these test methods

Nissan NES M0158 – Methods of Compound Corrosion Test

This Nissan engineering standard specifies the method to measure compound corrosion that uses the combined processes of salt spraying or salt solution immersion followed by drying and moistening. The process will simulate and accelerate corrosion of metal materials used on automobiles. Therefore this test will measure corrosion of metals of functional decorative parts together with the coating effect of inorganic or organic plating of vehicle models.

It is an accelerated laboratory corrosion test method that can be used to determine the corrosion resistance of automotive assemblies and components. It is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

As a rule, the testing equipment shall have the ability to generate and automatically repeat 3 different processes, i.e. salt solution spraying or immersion, drying and moistening.

• CCT-I Corrosion resistance in general (surface rust and penetrated rust): Vehicle body panel, road wheel, under-floor piping, drive shaft, propeller shaft, fastening parts (bolts and nuts) etc.
• CCT-IV External panel scab rust: External panel, external topcoat
• CCT-V Internally accelerated penetration of rust: Internal panel, box structure parts

See the hyperlinks above for information on each individual test standard

Nissan NES M0158 – CCT 5 (CCT-V)

This Nissan engineering standard specifies the method to measure compound corrosion that uses the combined processes of salt spraying or salt solution immersion followed by drying and moistening. The process will simulate and accelerate corrosion of metal materials used on automobiles. Therefore this test will measure corrosion of metals of functional decorative parts together with the coating effect of inorganic or organic plating of vehicle models.

It is an accelerated laboratory corrosion test method that can be used to determine the corrosion resistance of automotive assemblies and components. It is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

Test specimens are placed in an enclosed chamber and exposed to a changing climate that comprises of a relatively short period of salt immersion, followed by exposure to hot/humid and hot/dry atmospheres.  1 entire test cycle takes 2 hours to execute. The number of entire cycle repeats and therefore the test duration is variable.

The main test cycle begins with 5 minutes salt water immersion at 60°C  followed by 55 minutes of drying at 80°C , Humidity less than 30%rh . The final step is wetting at 60°C / 95%RH for 1 hour.

The total cycle is 2 hours and repeatable

The atmosphere in the chamber must be “instant setting” with a transition time of less than 10 seconds, and 1 cycle should take 2 hours. However, the process of Drying → Moistening should take less than 30 minutes.

Mazda MES MN 601G  Test Method for Paint Film

Section 27 for this test standard discusses the 5 class requirements for corrosion testing

Class 1 – Salt Spray Test

Class 2 – Perforation Corrosion Resistance Test

Class 3 – Scratch Corrosion Resistance Test

Class 4 – Edge Corrosion Resistance Test

Class 5 – Filiform Corrosion Resistance Test

Class 3-4 are commonly referred to as MAZDA MCT-3M which requires a fully enclosed chamber to perform the following test steps:

• 1 hour Salt Spray @ 35°C in accordance with JIS Z 2371
• 6 hours Drying @ 60°C /  10-30%RH
• 1 Hour wetting @ 50°C / 95% RH

The test profile runs for 8 hours and 180 cycles

This test can be ran in an Ascott Cyclic Chamber fitted with accessories ACC42 & ACC47

Cosmetic Corrosion Test Method for Automotive Parts

This standard specifies a test method for examining the cosmetic corrosion of metallic automotive parts and their surface treatments. It is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

Test specimens are placed in an enclosed chamber and exposed to a changing climate that comprises of the following 3 part repeating cycle. 2.0 hours exposure to salt spray at +35C according JIS Z 2371. This is followed by 4.0 hours of air drying in a climate of 20 to 30%RH at +60C. This is followed by 2.0 hours exposure to a condensing water climate (wetting) of 95 to 100%RH at +50C. The number of cycle repeats and therefore the test duration is variable.

The maximum transition times between each part of the test cycle are also specified as follows:

From salt spraying to air drying within 30 minutes.

From air drying to wetting within 15 minutes.

From wetting to salt spraying within 30 minutes.

Please see elsewhere in this document for details of JIS Z 2371.

Chamber volumes of less than 400 Litres are not permitted by this test standard.

This test is also referred to as a Cyclic Corrosion Test, often abbreviated to CCT.

Corrosion test method for Automotive Materials

This standard specifies a test method to determine the corrosion resistance of steel sheets for automotive use. It is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

Test specimens are placed in an enclosed chamber and exposed to a changing climate that comprises of the following 3 part repeating cycle. 2.0 hours exposure to salt spray at +35C according JIS Z 2371. This is followed by 4.0 hours of air drying in a climate of 20 to 30%RH at +60C. This is followed by 2.0 hours exposure to a condensing water climate (wetting) of 95 to 100%RH at +50C. The number of cycle repeats and therefore the test duration is variable.

The maximum transition times between each part of the test cycle are also specified as follows:

From salt spraying to air drying within 30 minutes.

From air drying to wetting within 15 minutes.

From wetting to salt spraying within 30 minutes.

Please see elsewhere in this document for details of JIS Z 2371.

Chamber volumes of less than 400 Litres are not permitted by this test standard.

This test is also referred to as a Cyclic Corrosion Test, often abbreviated to CCT.

This is an accelerated laboratory corrosion test method that can be used to determine the corrosion resistance of automotive assemblies and components. It is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

Test specimens are placed in an enclosed chamber and exposed to a changing climate that comprises of a relatively short period of salt spray, followed by exposure to hot/humid and hot/dry atmospheres. The entire test cycle comprises of a main cycle and a sub-cycle. 1 entire test cycle takes 24 hours to execute. The number of entire cycle repeats and therefore the test duration is variable.

The main test cycle begins with 10 minutes exposure to a continuous indirect spray of salt water solution, in a chamber temperature of +35C . This is followed by 155 minutes of air drying at +60C. This is followed by 75 minutes exposure to a high humidity climate of 95%RH at +60C.

This is then followed by a repetitive sub-cycle comprising of 160 minutes of exposure to an air drying at +60C, followed by 80 minutes exposure to a humid climate of 95%RH at +60C. This sub-cycle is repeated 5 times in total, before the main test cycle starts again.

This is an accelerated laboratory corrosion test method that can be used to determine the corrosion resistance of automotive assemblies and components. It is cyclic in nature, i.e.; test specimens are exposed to changing climates over time.

Test specimens are placed in an enclosed chamber and exposed to a changing climate that comprises of the following 3 part repeating cycle. 2.0 hours exposure to a continuous indirect spray of neutral (pH 6.5 to 7.2) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.0ml/80cm²/hour, in a chamber temperature of +35C . This is followed by 4.0 hours of air drying in a climate of 20 to 30%RH at +60C. This is followed by 2.0 hours exposure to a condensing water climate (wetting) of 95 to 100%RH at +50C. The number of cycle repeats and therefore the test duration is variable.

The maximum transition times between each part of the test cycle are also specified as follows:

From salt spraying to air drying within 30 minutes.

From air drying to wetting within 15 minutes.

From wetting to salt spraying within 30 minutes.