SH/T 0219-1992 Determination of Thermal Oxidation Stability of Heat Treatment Oils

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Card type: Test method

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

• Method number: SH/T 0219-92
• Full name: Determination of Thermal Oxidation Stability of Heat Treatment Oils
• English name: not provided in the available source
• Replacement relationship: replaces ZB E45 001-87
• Approval/implementation: approved by China Petrochemical Corporation 1992-05-20, implemented on 1992-05-20
• Reference adoption: clause 5.3 "Stability Test Method" in Japanese Industrial Standard JIS K 2242—1980 "Heat Treatment Oil"

2. Scope of application and non-applicability

• Scope of application: This standard applies to heat treatment oils.
• Non-applicability: not provided in the available source.

3. Method principle

In the presence of iron and copper catalysts, dry air is passed into the sample, and after continuous oxidation at a temperature of 165℃ for 24h, the kinematic viscosity and carbon residue of the sample before and after oxidation are determined; the degree of oxidation of the heat treatment oil is judged by the viscosity ratio and the increase in carbon residue.

4. Reagents and materials (purity / preparation)

4.1 Reagents

• 5.1 95% Ethanol: analytical reagent grade.
• 5.2 Benzene: analytical reagent grade.
• 5.3 Petroleum ether: 60~90℃, analytical reagent grade.

4.2 Materials

• 4.2.1 Emery cloth: grit size 150 or 180.
• 4.2.2 Low-carbon steel wire: conforms to GB 1300 medium H08 low-carbon steel wire, diameter 1.6 mm, length 3m.
• 4.2.3 Electrolytic copper wire: conforms to GB 466 medium 2 grade copper, diameter 1.6 mm, length 3m.
• 4.2.4 Solvent naphtha: conforms to SH 0004 specifications.

4.3 Preparation of cleaning solution

• Ethanol-benzene mixed solution: volume ratio 1:4 (see 6.1, 7.2).

5. Apparatus and equipment

• 4.1.1 Oxidation tube: made of heat-resistant hard glass, composed of a test tube, an air inlet tube and an outlet tube, see figure (the original text includes an oxidation tube figure, labeled: 1— cork stopper; 2— test tube; 3— air inlet tube; 4— catalyst coil; 5— sample liquid level; 6— constant-temperature bath liquid level; 7— air outlet tube; glass tube outer φ7, inner φ5; glass rod φ6; φ40; 300mL mark line).
• 4.1.2 Constant-temperature bath: equipped with electric heating device and stirring device, capable of maintaining constant temperature at 165±0.5℃, and capable of immersing the test tube in the bath to a depth of 350 mm.
• 4.1.3 Thermometer: 0~200℃, with a scale division of 0.5℃.
• 4.1.4 Flowmeter: flow rate 10±0.1 L/h.
• 4.1.5 Catalyst coil winding rod: same as the catalyst coil winding rod in GB/T 12581.

6. Recommended operating conditions

• Oxidation temperature: 165±0.5℃.
• Air flow rate: 10±0.1 L/h (dry air).
• Oxidation time: continuous 24h.
• Number of test tubes: three test tubes are used for the same sample.
• Sample liquid level: the sample liquid level in the test tube shall be lower than the constant-temperature bath liquid level by 60mm.
• Viscosity measurement temperature: when the kinematic viscosity of the sample before oxidation is less than 100 mm²/s at 40℃, measure the kinematic viscosity at 40℃; when it is greater than 100 mm²/s (including 100 mm²/s), measure the kinematic viscosity at 100℃.

7. Sampling and sample preparation

• 7.2 Place 300mL of sample into a clean, dry test tube.
• Wash the catalyst spiral coil with ethanol-benzene mixed solution, allow it to dry naturally or dry it with a hair dryer, then immediately use tweezers to place the spiral coil onto the air inlet tube, and put them together into the test tube.
• Other sampling requirements: not provided in the available source.

8. Analysis procedure

8.1 Cleaning the oxidation tube (6.1)

Clean successively with solvent naphtha, ethanol-benzene mixed solution (volume ratio 1:4), 95% ethanol, water and chromic acid cleaning solution, then rinse several times with tap water, finally rinse with distilled water, and place in an oven to dry.

8.2 Preparation of catalyst (6.2)

• 6.2.1 Before use, clean the 3m long low-carbon steel wire and electrolytic copper wire with a piece of absorbent cotton moistened with petroleum ether, then polish with emery cloth of grit size 150 or 180 to expose a fresh surface, and then wipe clean with a clean silk cloth.
• 6.2.2 Combine one end of the 6.2.1 prepared low-carbon steel wire and electrolytic copper wire, insert them into the front notch of the catalyst coil winding rod, then rotate the handle to wind into a coil; one end of the coil shall align with the mark line at 300mL of the test tube.

8.3 Test procedure (7)

• 7.1 Heat the constant-temperature bath and maintain it at 165±0.5℃.
• 7.2 Place 300mL of sample into a clean, dry test tube, then wash the catalyst spiral coil with ethanol-benzene mixed solution, allow it to dry naturally or dry it with a hair dryer, then immediately use tweezers to place the spiral coil onto the air inlet tube, put them together into the test tube, and then place them together into the constant-temperature bath at 165±0.5℃. The sample liquid level in the test tube shall be lower than the constant-temperature bath liquid level by 60mm.
• 7.3 Pass dry air into the air inlet tube, control the flow rate at 10±0.1 L/h, and record the start time. Three test tubes are used for the same sample, and the oxidation test is carried out continuously for 24h.
• 7.4 After the oxidation test is completed, pour the samples from the three test tubes into three bottles respectively, stir thoroughly, then take samples, determine the kinematic viscosity according to GB/T 265, and determine the carbon residue before and after oxidation according to GB/T 268.

9. Qualitative and quantitative determination and calculation formulas

9.1 Viscosity ratio R is calculated according to formula (1):

R = ν / ν₀

Where:

• ν₀——the viscosity of the sample before oxidation at the specified temperature, mm²/s;
• ν—— the viscosity of the sample after oxidation at the specified temperature, mm²/s.

(Note: the formula symbols in the original text source-text extraction contain noise; the correspondence between ν₀ and ν is organized according to contextual semantics, requires confirmation against the source standard (source-text extraction).)

9.2 Increase in carbon residue X [% (m/m)] is calculated according to formula (2):

X = X₂ − X₁

Where:

• X₁——the carbon residue of the sample before oxidation, % (m/m);
• X₂——the carbon residue of the sample after oxidation, % (m/m).

10. Precision

Judge the reliability of the results according to the following provisions (95% confidence level).

Repeatability: For the viscosity ratio and increase in carbon residue obtained respectively from the three oxidation tubes, the difference between each value and the arithmetic mean of the three results shall not exceed the following values for their arithmetic mean.

(Note: the table in the original text source-text extraction is disordered in layout; the above table is organized according to the original text order, and the specific row correspondence requires confirmation against the source standard (source-text extraction).)

11. Report

Take the arithmetic mean of the test results that meet the precision requirements of Chapter 9 (rounded to one decimal place) as the viscosity ratio and increase in carbon residue.

(Note: the original text says "Chapter 9 Precision", but precision is actually Chapter 9, and the report is Chapter 10; this is how the original text states it, requires confirmation against the source standard (source-text extraction).)

12. Referenced documents

• GB/T 265 Petroleum products — Determination of kinematic viscosity and calculation of dynamic viscosity
• GB/T 268 Petroleum products — Determination of carbon residue (Conradson method)
• GB 466 Classification of copper
• GB 1300 Steel wire for welding
• GB/T 12581 Determination of oxidation characteristics of inhibited mineral oils
• SH 0004 Solvent naphtha for rubber industry

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