SH/T 0220-1992 Determination of Cooling Performance of Heat Treatment Oils

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Card type: Test method

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

• Standard number: SH/T 0220-92
• Chinese name: Determination of Cooling Performance of Heat Treatment Oils
• English name: not provided in the available source
• Replacement relationship: replaces ZB EA5 003—88
• Other: confirmed in 2004; approved by China Petrochemical Corporation 1992-05-20, implemented on 1992-05-20

2. Scope of application and non-applicability

• This standard specifies the method for determining the cooling performance of heat treatment oils based on cooling curves.
• This standard applies to heat treatment oils.
• Not applicable: not provided in the available source.

3. Method principle

After the silver probe is heated to 810°C and held for 2~3min, it is quickly quenched into the sample, and the function curve of the silver probe temperature decrease with time is continuously recorded; the cooling performance of the sample is determined from the cooling curve.

4. Reagents and materials (purity / preparation)

• 4.2.1 Metallographic abrasive paper: M10 (800) or M7 (1000).
• 4.2.2 Polishing paste: green soap polishing paste.
• 4.2.3 Silk cloth: white or yellow silk cloth.
• 4.2.4 Solvent naphtha: conforms to SH 0004 specifications.
• 4.2.5 Calibration liquid: dioctyl phthalate, chemically pure.
• Appendix A Standard oil quality indicators (Table A1): kinematic viscosity (50°C) 19–20 mm²/s (GB/T 265); flash point (open cup) not lower than 180°C (GB/T 267); molecular weight 310–325 (Appendix B); water content none (GB/T 260).
• Appendix B Reagents: phenanthrene (high purity, used as standard sample; other pure substances may also be used as standard samples, provided that the vapor pressure of the standard sample under the measurement conditions does not exceed 26.66Pa (0.2mmHg)); benzene (guaranteed reagent grade, used as solvent; in general benzene is used as solvent, and when the sample cannot be completely dissolved in benzene, chloroform, acetone or other solvents may also be used); benzene (chemically pure, used for washing syringe needles); petroleum ether 30~60°C, analytical reagent grade, used for washing syringe needles.

5. Instruments and equipment

• 4.1.1 The cooling performance measuring apparatus is shown in Figure 1, and consists of a tube furnace equipped with a controllable temperature device, a X-Y function recorder, a potentiometer, and a silver probe lifting mechanism, etc.
• 4.1.2 Silver probe: ZJY-10 integrally extruded silver probe; its structure and main technical conditions are given in Appendix A.
• 4.1.3 Multimeter: class 0.5.
• 4.1.4 X-Y Function recorder: model IZ3-204; accuracy class 0.5; specifications 25×30, 220V, 50Hz, 0.5A (or other recorder models with the same specifications and accuracy).
• 4.1.5 Potentiometer: accuracy class 0.1.
• 4.1.6 Beaker: 300mL.
• 4.1.7 Closed electric furnace: 1kV (requires confirmation against the source standard (source-text extraction), suspected to be 1kW).
• 4.1.8 Thermometer: 0~150°, scale division value 1°C.
• Appendix A: The manufacturing dimensions and precision of the silver probe must meet the requirements of Figure A1; the deviation of the center of the thermocouple hot junction from the centerline of the silver rod diameter 10mm must not exceed 0.2mm; the thermocouple hot junction and the silver rod body should be tightly joined, and after magnification 100 times inspection there must be no voids or inclusions; the silver probe must be made of grade one (purity 99.99%) or grade two (purity 99.95%) pure silver (GB 4135); the thermocouple is made of nickel-chromium-nickel-silicon thermocouple wire with diameter 0.5mm, and when the free end is 0°C its thermoelectric potential shall conform to the provisions of EU-2 (GB/T 2614); the thermocouple uses a porcelain tube, outer diameter 3mm, inner diameter 0.6mm two-hole porcelain tube, with center distance between the two holes 1.2mm.
• Appendix B: B2.1 molecular weight measuring instrument (recommended to use West German Knauer molecular weight measuring instrument); B2.2 volumetric flask 5mL or other capacity; B2.3 syringe 1mL, needle with spring.

6. Recommended operating conditions

• Silver probe heating temperature: 810°C ± 2°C, hold for 2~3min.
• Sample amount: 250mL, heated to 80°C ± 2°C.
• Quenching time: within 2s.
• X-Y Function recorder paper speed: 1s/mV setting.
• Distance between the lower end of the silver probe and the bottom of the beaker: 15mm.
• Calibration liquid amount: 250mL, heated to 80°C ± 2°C.
• Appendix B Test temperature: 45°C when benzene is used as solvent; 37°C when chloroform or acetone is used as solvent.

7. Sampling and sample preparation

• 5.1 Use silk cloth coated with polishing paste to polish the surface of the silver probe so that it presents a bright metal surface. Then clean it with solvent naphtha, wipe it dry with clean silk cloth, and use a multimeter to measure whether the two thermocouple wires are connected.
• 5.2 Place the 300mL beaker under the tube furnace as shown in Figure 1, place the silver probe prepared according to clause 5.1 at the central position of the tube furnace, and adjust the geometric center of the silver probe to be located at the center of the beaker, so that the lower end of the silver probe is at a distance of 15mm from the bottom of the beaker.
• 5.3 Connect the silver probe thermocouple wires to the potentiometer and the X-Y function recorder respectively (see Figure 1). Set the paper speed of the X-Y function recorder to the 1s/mV setting.
• 5.4 Heat the silver probe in the tube furnace to 810°C ± 2°C, and hold for 2~3min.
• 5.5 Add 250mL calibration liquid to the 300mL beaker, and heat to 80°C ± 2°C.
• 5.6 Start the paper feed switch of the X-Y function recorder, and quench the silver probe, which has been heated to 810°C ± 2°C, into the calibration liquid within 2s.
• 5.7 Determine the cooling performance of the calibration liquid from the cooling curve; it shall meet the following requirements: characteristic temperature 510°C ± 10°C; time from 800°C cooling to 400°C 5.3s ± 0.3s. If the above requirements are not met, the silver probe should be re-polished according to clause 5.1, and if necessary, gently ground with metallographic abrasive paper and then polished, and then recalibrated.
• 6.1 Heat the calibrated silver probe in the tube furnace to 810°C ± 2°C, and hold for 2~3min.
• 6.2 Pour 250mL of sample into the beaker, and heat to 80°C ± 2°C, and place it under the tube furnace at the specified position according to clause 5.2.
• 6.3 Start the paper feed switch of the X-Y function recorder, quench the silver probe into the sample within 2s, and record the function curve of the silver probe temperature changing with time.
• 6.4 After each test, the silver probe should be cleaned. When the silver probe has cooled below 60°C, clean it with solvent naphtha. If a paint film remains on the surface of the silver probe or the measured cooling curve is not repeatable, it should be treated and calibrated according to clause 5.7.

8. Analytical procedure

See section 7 (the source text lists preparation work and test procedure separately in chapters 5 and 6; this section summarizes according to the source text 6.1~6.4):

• 6.1 Heat the calibrated silver probe in the tube furnace to 810°C ± 2°C, and hold for 2~3min.
• 6.2 Pour 250mL of sample into the beaker, and heat to 80°C ± 2°C, and place it under the tube furnace at the specified position according to clause 5.2.
• 6.3 Start the paper feed switch of the X-Y function recorder, quench the silver probe into the sample within 2s, and record the function curve of the silver probe temperature changing with time.
• 6.4 After each test, the silver probe should be cleaned. When the silver probe has cooled below 60°C, clean it with solvent naphtha. If a paint film remains on the surface of the silver probe or the measured cooling curve is not repeatable, it should be treated and calibrated according to clause 5.7.

9. Qualitative and quantitative determination and calculation formulas

• Calculate the characteristic temperature of the sample and the time from 800°C cooling to 400°C from the cooling curve.
• Calculation method: draw two tangent lines along the upper abrupt-change region of the curve, draw a line parallel to the X axis through the intersection of the tangent lines to intersect the curve at a point; the temperature corresponding to this point is the characteristic temperature; draw a parallel line at 400°C on the Y axis to intersect the curve at a point; the time corresponding to this point is the time from 800°C cooling to 400°C (see Figure 2).
• Appendix B Calculation: ΔV = K × (M1/M2) × C2 (formula B3); K = M × (ΔV/Cw)₀ (B5.4); sample molecular weight M = (ΔV/Cw)₀ (formula B4, as in the source text, requires confirmation against the source standard (source-text extraction)).
• Appendix B Method summary: ΔT = A × (M1/M2) × C2 (formula B1); ΔV = B × (E/T²) × ΔT (formula B2).

10. Precision

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

• 8.1 Repeatability: the difference between two results obtained by the same operator in repeated determinations shall not exceed the value specified in Table 1.
• 8.2 Reproducibility: the difference between two results submitted by different laboratories shall not exceed the value specified in Table 1.

Table 1

11. Report

Take the arithmetic mean of the two results that meet the requirements of Chapter 8 as the characteristic temperature and the time from 800°C cooled to 400°C.

12. Normative References

• GB/T 260 Petroleum products—Determination of water
• GB/T 265 Petroleum products—Determination of kinematic viscosity and calculation of dynamic viscosity
• GB/T 267 Petroleum products—Determination of flash point and fire point (open cup method)
• GB/T 2614 Nickel-chromium/nickel-silicon thermocouple wires and reference tables
• GB 4135-84 Silver
• SH 0004 Solvent naphtha for the rubber industry
• Appendix B Determination of number-average molecular mass of petroleum products and additives (vapour pressure osmometry) (supplementary document)
• Reference adoption of Japanese Industrial Standard JIS K 2242—1980 'Heat treatment oils', clause 5.2 'Cooling performance test method'

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