SH/T 0533-1993 Rust corrosion evaluation method for rust-preventive oil and grease test specimens after rust-prevention testing

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

1. Method number / full title / English title / replacement relationship

• Standard number: SH/T 0533-93 (confirmed in 2004)
• Chinese title: Rust corrosion evaluation method for rust-preventive oil and grease test specimens after rust-prevention testing
• English title: not provided in the available source
• Replacement relationship: replaces SY 2751-82
• First issued: 1975 (see additional notes)

2. Scope of application and non-application

• Applicable: rust corrosion evaluation of metal test specimens after salt spray testing, humid heat testing, and atmospheric semi-exposure testing of rust-preventive oils and greases.
• Not applicable: not provided in the available source.

3. Method principle

Overlay the rust corrosion evaluation plate on the test specimen to be evaluated after salt spray testing, humid heat testing, or atmospheric semi-exposure testing of rust-preventive oils and greases, so that the square frame is exactly at the center of the test specimen. Observe the squares within the square frame serving as the effective area, and count the total number of rusted squares within the effective area. This is called the degree of rusting and is expressed as a percentage.

4. Reagents and materials (purity / preparation)

not provided in the available source.

5. Instruments and equipment

• Rust corrosion evaluation plate: made of a colorless transparent flat plate of 50mm × 50mm × 2mm. At the center there is a 40mm × 40mm square frame, within which are engraved 100 square cells of 4mm × 4mm, and the width of the engraved lines of the cells is not greater than 0.1mm.
• Note: the original text “40imn” is source-text extraction noise; based on the context and the calculation from 100 cells of 4mm×4mm, it should be 40mm, requires confirmation against the source standard (source-text extraction).

6. Recommended operating conditions

• Observation conditions: observe with the naked eye under sufficient light.
• Effective area: the 100 squares of 40mm × 40mm at the center.

7. Sampling and specimen preparation

not provided in the available source.

8. Analytical procedure

Overlay the rust corrosion evaluation plate on the test specimen to be tested, so that the square frame is exactly at the center of the test specimen. Observe with the naked eye under sufficient light, take the 100 squares of 40mm × 40mm at the center as the effective area, and count the total number of rusted squares within the effective area. This is called the degree of rusting and is expressed as a percentage.

For rust spots on the dividing lines or intersections of the rust corrosion evaluation plate, when their size is equal to or greater than 1mm, any that extend into a square are counted as a rusted square. When smaller than 1mm, they are counted as one rusted square.

• Note: The dimension and unit are unclear in the source transcription. Their interpretation as 1 mm is provisional and requires verification against the original.

9. Qualitative and quantitative determination and calculation formula

9.1 Provisions for the evaluation surface (Chapter 5 Judgment of results)

• 5.1 For atmospheric semi-exposure test specimens, evaluate both surfaces, and take the arithmetic mean of the rust degrees of the two surfaces as the degree of rusting.
• 5.2 For salt spray test specimens, evaluate the exposed surface.
• 5.3 For humid heat testing, take the more heavily rusted surface as the evaluation surface.
• 5.4 On each evaluation surface, evaluate the degree of rusting and grade according to the table below.

9.2 Rust corrosion grading table (Article 5.4)

• Note: although the degree of rusting is 1%—3%, if among them there is 1 spot equal to or greater than 1mm, the rating is set as grade 2.
• Note: the original text “not greater than I-” is source-text extraction noise; based on the context it should be “not greater than 1mm”, requires confirmation against the source standard (source-text extraction).
• Note: for the two rows “Number of rust spots” and “Rust spot size”, the original table does not give corresponding content at grades 3, 4, and 5, and they are marked as not provided in the available source.

9.3 Excluded areas on the evaluation surface

Unless otherwise specified, on the evaluation surface of each test specimen, rust corrosion occurring on the periphery at a distance of 5mm from the edge and at the two holes shall not be considered during evaluation.

9.4 Color change grading for non-ferrous metals (Article 5.5)

• Grade 0 — no change (compared with the surface of a newly polished test specimen, no change in luster);
• Grade 1 — slight change (compared with the surface of a newly polished test specimen, uniform slight discoloration);
• Grade 2 — moderate change (compared with the surface of a newly polished test specimen, obvious discoloration);
• Grade 3 — severe change (compared with the surface of a newly polished test specimen, severe discoloration with obvious corrosion).

10. Precision

not provided in the available source.

11. Report

not provided in the available source.

12. Referenced documents

not provided in the available source.

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick reference Q&A