GB/T 14906-2018Classification of internal combustion engine oils viscosity (English PDF)

Foreword

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

This standard replaces GB/T 14906-1994 "Internal combustion engine oil viscosity classification". Compared with GB/T 14906-1994, except for editorial modifications, the main technical changes are as follows:

--- Increased the viscosity level of 8, 12, 16 (see Table 2);

--- "Low temperature viscosity" was changed to "low temperature start viscosity", and the test conditions and index limits were changed (see Table 2, 1994 edition table);

--- "Boundary pumping temperature" was changed to "Cryogenic pumping viscosity", and the test methods and index limits were changed (see Table 2, 1994 edition table)

--- The viscosity index of 100 °C in the 20 viscosity grade is changed from "not less than 5.6mm²/s~ less than 9.3mm²/s" to "not less than 6.9mm²/s~ less than 9.3mm²/s" (see Table 2, table of 1994 edition);

--- Increased high temperature and high shear viscosity testing items and testing methods (see Table 2);

--- Increased the representation of SAE8~SAE20 high temperature viscosity grade (see 4.3);

--- Added Appendix A "SE, SF quality grade gasoline engine oil and CC, CD quality grade diesel engine oil and agricultural diesel engine oil viscosity Degree classification" (see Appendix A).

1 Scope

This standard specifies the viscosity classification of internal combustion engine oil only from the perspective of rheology.

This standard applies to the determination of the viscosity grade of internal combustion engines and does not relate to other characteristics of the oil.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 265 petroleum product kinematic viscosity measurement method and dynamic viscosity calculation method

GB/T 6538 engine oil apparent viscosity determination cold start simulator

GB/T 9171 engine oil boundary pumping temperature measurement method

NB/SH/T 0562 Determination of yield stress and apparent viscosity of engine oil at low temperature

SH/T 0618 Lubricating oil dynamic viscosity method under high shear conditions (Rayfanfelt method)

SH/T 0703 Lubricating oil at high temperature and high shear rate conditions, apparent viscosity measurement (multicapillary viscometer method)

SH/T 0751 Viscosity measurement at high temperature and high shear rate (cone plug viscometer method)

3 Classification methods

3.1 This standard uses two series of viscosity grades including letter W and letter W. A group of single-stage internal combustion engine oils containing the letter W are low Temperature start viscosity, low temperature pumping viscosity and kinematic viscosity at 100 °C to separate viscosity grade; a group of single stage internal combustion engine oil without letter W is The viscosity is classified by the kinematic viscosity at 100 ° C and the high shear viscosity at 150 ° C.

3.2 A multi-viscosity class of internal combustion engine oil, its low temperature start viscosity and low temperature pumping viscosity should meet the requirements of a Class W in the series, the same The 100 ° C kinematic viscosity and 150 ° C high temperature high shear viscosity should be within the viscosity range specified by a non-W classification in the series.

4 Viscosity grade representation

4.1 The viscosity grade in this standard is based on six low-temperature viscosity grades (WW, 5W, 10W, 15W, 20W, 25W) and eight The high temperature viscosity grade number (8, 12, 16, 20, 30, 40, 50, 60) containing the letter W is indicated.

4.2 Viscosity grades are divided into single grade oil and multi grade oil. Any Newtonian oil can be labeled as a single grade oil (with or without W). Some aggregated The viscosity of the viscosity index improver is non-Newtonian oil, and should be marked with appropriate multi-viscosity grade (including W and high temperature grade), ie containing W viscosity grade. And high temperature viscosity grade, and the difference between the two viscosity grades is greater than or equal to 15. For example, a multi-grade oil can be labeled 10W-30 or 20W-40 without Marked as 10W-20 or 20W-20. An oil may meet multiple W grades at the same time, and the marked W grade or multi viscosity grade is only the lowest. W grade number. For example, a multi-grade oil meets 10W, 15W, 20W, 25W, and 30 grades at the same time, and the viscosity grade can only be labeled 10W-30.

4.3 For engine oils with viscosity class SAE8~SAE20, the 100°C kinematic viscosity may meet more than one high temperature viscosity at the same time. Degree level requirement, when marking a single-stage oil or multi-grade oil that meets the requirements of more than one high-temperature viscosity grade, only the maximum temperature is required to be marked. Viscosity grade for high shear viscosity. See Table 1 for examples of their markings.