GB/T 1174-1992 English PDF (GBT1174-1992)
GB/T 1174-1992 English PDF (GBT1174-1992)
See Chinese contents: GB/T 1174-1992
GB/T 1174-1992: Cast bearing metals
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
Cast bearing metals
APPROVED ON: NOVEMBER 05, 1992
IMPLEMENTED ON: OCTOBER 01, 1993
Issued by: State Bureau of Technical Supervision
Table of Contents
1 Subject contents and scope of application ... 3
2 Normative references ... 3
3 Representation of alloy designation ... 3
4 Technical requirements ... 4
5 Test methods and inspection rules ... 6
Appendix A (Informative) Bimetallic sliding bearing - Bonding test - Ultrasonic testing for bonding defects of bearing alloy layer of not less than 2 mm thickness ... 10
Appendix B (Informative) Bimetallic sliding bearing - Bonding test -
Determination of the bonding strength of the bearing alloy layer with a thickness of not less than 2 mm ... 16
Additional information: ... 20
NATIONAL STANDARD OF THE PEOPLE REPUBLIC OF
Cast bearing metals
1 Subject contents and scope of application
This standard specifies the technical requirements and inspection rules, for cast tin-based, lead-based, copper-based, aluminum-based bearing alloys.
This standard applies to the manufacture of tin-based, lead-based bimetallic sliding bearings, AND copper-based and aluminum-based alloy integral sliding bearings.
2 Normative references
GB 228 Metallic materials - Tensile testing at ambient temperature
GB 231 Metallic materials - Brinell hardness test
GB 1173 Casting aluminum alloys - Technical specifications
GB 1176 Specification for cast copper alloys
GB 1198 Methods for chemical analysis of aluminum
GB 3260.1 ~ 3260.9 Methods for chemical analysis of tin
GB 4103.1 ~ 4103.12 Methods for chemical analysis of lead and lead alloys GB 8002 Methods for chemical analysis of tin bronze
YB 55 Methods for chemical analysis of aluminum bronze
3 Representation of alloy designation
The designation of cast bearing alloy is composed of the chemical symbols, of the base metal elements AND the main alloying elements. The main alloying element is followed by a number, which indicates its nominal percentage content (the nominal percentage content is the rounded value of the average percentage content of the element). If the nominal percentage content of GB/T 1174-92
Replacing GB 1174-74
5 Test methods and inspection rules
5.1 Chemical composition
5.1.1 The inspection of the chemical composition of alloy shall be carried out, in accordance with the requirements of GB 3260.1 ~ GB 3260.9, GB 4103.1 ~ 4103.12, GB 8002, YB 55. Under the condition of ensuring the accuracy of the analysis, it is allowed to use other methods. When there is a dispute, the chemical analysis method shall be used for arbitration.
5.1.2 For the chemical composition inspection, it shall be carried out, according to each smelting furnace OR according to the requirements of the purchaser. Chemical composition specimens can be taken from castings (including the attached specimen of castings).
5.1.3 For the inspection of chemical composition, a specimen is sent for the first time. If the analysis result meets the requirements of Table 1, the alloy's chemical composition is qualified. If it does not meet the requirements of Table 1, it is allowed to send another specimen. If the analysis result meets the requirements of Table 1, the chemical composition of alloy of the smelting furnace is qualified; otherwise, it is unqualified.
5.1.4 For the inspection of chemical composition, it may only analyze the main elements. For the content of other elements, it can be spot-checked as required by the purchaser.
5.2 Mechanical performance
5.2.1 For cast bearing alloys, only the as-cast (F) mechanical properties are tested. The values are as shown in Table 2.
5.2.2 For the testing of mechanical properties of the alloy, based on each smelting furnace, one specimen (or a test block) shall be sent for the first time, to determine the mechanical properties. If it meets the requirements of Table 2, the mechanical properties of the alloy of this furnace are qualified. If it does not meet the requirements of Table 2, it is allowed to take two more specimens (or two test blocks), for inspection again. If both specimens (or two test blocks) are qualified, the mechanical properties of the alloy of this furnace are qualified; otherwise, the mechanical properties of the alloy of this furnace are unqualified. 5.2.3 When a single casting specimen is found, by naked eyes, to have casting defects, OR the inspection result is unqualified due to the failure of the test itself, it may not be counted in the number of inspections. Replace the specimen; re- submit it for inspection.
5.2.4 In the case of stable production (including: the stability of raw materials, Appendix A
Bimetallic sliding bearing - Bonding test - Ultrasonic testing for bonding defects of bearing alloy layer of not less than 2 mm thickness
This Appendix refers to ISO 4386/1 (1982 edition).
A1 Scope of application
This Appendix specifies the ultrasonic testing method for the bonding defect, BETWEEN the bearing alloy AND the backing (i.e., bonding-off). The backing material is steel, copper alloy or cast iron, on which a lead-based or tin-based bearing metal, which has a thickness of not less than 2 mm, is casted.
This Appendix only describes the pulse echo of the sound wave, which is input from the surface of the bearing alloy layer, that is, the sound energy, which is reflected from the bonding surface, is used to determine the quality of the bonding.
The following symbols are used in this Appendix:
IS: Input signal
BE: Bonding echo
WE: Back wall echo
RE: Datum echo (or reference echo).
A3 Testing equipment
The ultrasonic device used for testing shall have an amplifier, which uses decibel (dB) as the scale, whose measurement range can be adjusted.
Under normal circumstances, it shall use a standard design transducer, which has a diameter of 10 ~ 30 mm AND a frequency of 2 MHz. Only when the
resolution cannot meet the requirements, it shall use a high frequency
transducer, such as 4 MHz, OR a dual crystal transducer.
The measurement range on the screen can be adjusted by a standard
specimen, for example, using a stepped specimen to adjust. Within the
measurement range, at least two echoes shall be displayed. The material and thickness of the standard specimen shall be the same as the actual bearing. bonding, BETWEEN the bearing alloy AND the backing, does not meet the
requirements. If there is no back wall echo, BUT only repeated (at least three) combined echoes, it means that, there is no bonding, as shown in Figure A2. During the testing process, both of these results indicate the existence of bonding defects.
When the backing is thick and small, OR when a dual crystal transducer is used, due to the dispersion of the sound beam OR the weakening of the sound wave, even if the bonding is good, the back wall echo will be smaller than the combined echo. At this time, the ratio of the height between the two echoes of the ideal bonding to the defective bonding, shall be determined by the use of a standard specimen.
A6.1.2 Perform the testing, based on the reduction in the height of back wall echo. Use a standard steel test block to calibrate the testing equipment. Install the test block on the tested bearing, to obtain at least two echoes. The first echo is adjusted to 3/4 of the screen height. The lateral magnification shall be adjusted, to facilitate the display of the total wall thickness; the bonding defect or the backing material defect may be indicated, by the position of the intermediate wave, before the first back wall echo. The severity of the defect can be judged, by the reduction of the height of back wall echo. Refer to Figure A3 and Figure A4. For example, in the bearing evaluation process, the echo height of the more significant defects is not more than 50% of the screen height. A6.2 Testing of non-back wall echo
Use the reference echo of the standard specimen (same thickness, same
bearing alloy, backing material), to test the bonding. Adjust the reference echo to 80% of the screen height. Refer to Figure A5 and Figure A7. When the first combined echo is smaller than the reference echo, as shown in Figure A6, it is proved that the bonding is good. When the first echo, which is reflected from the bonding area, is equal to the reference echo, it indicates that there is a certain bonding defect, as shown in Figure A8. There is also a
misunderstanding, that is, if there is looseness, in the area close to the bonding defect, it is often regarded as a bonding defect.
A7 Calibration of bonding defects
Generally, calibration is required for bonding defects, which are equal to or greater than one-half of the diameter of the transducer.
A7.1 Calibration of defect range
If possible, it shall indicate the boundary of the defect range. The boundary, BETWEEN the bonding AND the non-bonding, can be determined by the center position of the transducer. For isolated point defects, it is expressed as one-half The markings of test levels and defect groups in this Appendix are as follows: For example, if the test is level 2 AND the defect group is C, it is marked as GB/T 1174/T-2C.
A9 Test report
The test report can be written, through negotiation, between the supplier and the buyer.
The test report shall include the following:
a. The size and material of the sliding bearing;
b. The thickness of the alloy layer of tested sliding bearing;
c. The testing equipment;
d. The model and size of the transducer;
e. The test frequency;
f. The magnification, range
g. Standard (reference) specimen (size and material);
h. Marking of the location and size of the defect, in the drawing on the bearing surface;
i. The test date, bearing manufacturer.