GB/T 35858-2018Rubber,vulcanized—Test method of salt mist aging (English PDF)

Foreword

This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This Standard specifies the test method for determining the change of appearance and physical properties of vulcanized rubber after it is aged in salt mist environment.

This Standard is applicable to the evaluation of the resistance of vulcanized rubber to salt mist aging.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 2941, Rubber - General procedures for preparing and conditioning test pieces for physical test methods

GB/T 6682, Water for analytical laboratory use - Specification and test methods

GB/T 10587, Specifications for salt mist testing chambers

3 Method summary

Expose a vulcanized rubber sample to a salt mist environment. Under the action of hot air and salt solution, the performance of the sample before and after aging is tested after a specified time so as to evaluate the salt mist aging resistance […]

7 Test conditions

d) Salt mist settling rate. 1.0 mL/(h·80cm²) ~ 2.0 mL/(h·80cm²).

7.2 The test period can be determined according to actual needs or consultations of relevant parties. The following test cycles are recommended.

a) 24h, or multiple of 24h;

b) 7d, or multiple of 7d.

7.3 For sample adjustment, unless otherwise specified, the sample shall be adjusted according to the relevant provisions of GB/T 2941 before and after the salt mist aging test.

8 Test steps

8.1 The preparation of the salt mist solution (sodium chloride solution) includes the following two steps.

a) Preparation of sodium chloride solution. dissolve sodium chloride (5.1) of which the mass is (5±1) portions in water (5.4) of which the mass is 95 portions;

b) Sodium chloride solution pH adjustment. when the temperature is (35±2)°C, the pH shall be controlled within the range of 6.5~7.2. If the pH value is out of range, use hydrochloric acid solution (prepared from 5.2 hydrochloric acid at a concentration of 0.1mol/L~0.5mol/L) or sodium hydroxide solution (prepared from 5.3 sodium hydroxide at a concentration of 0.1mol/L~0.5mol/L) to adjust.

8.2 First adjust the sample according to 7.3. Then determine the performance of the sample before aging.

8.3 Open the salt mist aging box. After the specified test conditions are met, the sample is put into the test and the test time is calculated.

8.4 The sample shall be placed in the effective working area of the salt mist aging box for exposure. At the same time, care shall be taken to avoid accumulation of fluid on the surface of the sample. Samples shall not overlap or touch each other, and the spacing shall not be less than 5mm. The distance between the sample and the wall of the box shall not be less than 70mm.

8.5 Salt mist settling rate shall be monitored at least every 24h to ensure it is within the specified range. The salt mist settling rate test method shall be carried out in accordance with the provisions of GB/T 10587.

8.6 After the specified test time is reached, the sample is taken out from the salt mist aging box. Use distilled water or deionized water to wash the salt or other […]