This standard is formulated for the conventional mechanical properties of soft and hard soldering joints. This standard is applicable to the determination of the instantaneous tensile strength, shear strength and high temperature creep strength of hard soldering joints of ferrous metals, non-ferrous metals and their alloys in cold, room temperature and hot states, as well as the instantaneous shear strength and creep strength of soft soldering joints in cold, room temperature and hot states. This standard specifies the shape of the tensile and shear specimens used and the unified operation method so that the test results can be reproduced and compared. GB/T 8619-1988 Brazing joint strength test method GB/T8619-1988 standard download decompression password: www.bzxz.net

Scope of application
National Standard of the People's Republic of China
Method of the strength test for brazed and soldered seam
This standard is formulated for the conventional mechanical properties of soft and hard soldered seams. UDC 621.791.062
: 620.172
GB 8619--88
This standard is applicable to the determination of the instantaneous tensile strength, shear strength and high temperature creep strength of hard soldered seams of ferrous metals, non-ferrous metals and their alloys in cold, room temperature and hot states, as well as the instantaneous shear strength and creep strength of soft soldered seams in cold, room temperature and hot states. This standard specifies the shapes of the tensile and shear specimens used and the unified operating methods so that the test results can be reproduced and compared.
2 Test piece preparation
2.1 Test piece and joint form
2.1.1 Conventional shear test piece
The test piece dimensions and assembly are shown in Figure 1. During assembly, a certain uniform gap should be maintained. $20bZxz.net
X: Determined by spacing
Test part drawing
Approved by the National Bureau of Standards on February 1, 1988
Assembly before brazing
Figure 1 Dimensions of shear test parts
Test piece after brazing
Implementation on August 1, 1988
2.1.2 Conventional tensile test piece
GB8619-88
The test piece dimensions and assembly are shown in Figure 2. During assembly, the brazing surfaces of the test piece are opposite and have a predetermined assembly gap.中13±:
0. 5 × 4
#15 ± 0.
Assembly before brazing
Test piece figure
2.2 Selection of parent material and joint gap
Figure 2 Dimensions of brazing test parts
Test piece after brazing
The selection of parent material for the test should ensure that the fracture load of the needle seam is lower than the load of the elastic limit of the parent material to ensure failure at the brazing seam. In special applications, the test piece material should be the metal of the component used, and the joint gap should also be the gap of actual application. The parent material and joint gap should be noted in the report. 2.3 Surface preparation
The surface to be welded should be cleaned to remove oxide scale, lubricant, oil, paint, etc. The cleaning process and cleaning agent should be suitable for the requirements of the parent material. 112
Before brazing, the surface to be welded can be polished with emery cloth. GB 8619-88
For special applications, the surface condition should be equivalent to the requirements of the actual component. 2.4 Application of brazing filler metal and brazing flux
The test piece is assembled in a vertical position, and the brazing filler metal is pre-placed on one side of the joint in an appropriate form (wire, powder, sheet, block, etc.) or fed manually. Its amount should be sufficient to fill the brazing gap after melting. If brazing flux must be used, the test needle should meet the requirements of the brazing filler metal and the base material, and its application should follow the manufacturer's instructions. The brazing filler metal and brazing flux used should be indicated in the report. 2.5 Heating brazing
2.5.1 The test piece is clamped vertically in the position shown in Figures 1 and 2, and the support frame should not hinder the expansion and contraction of the test piece assembly during heating and cooling. 2.5.2 When heating with an oxygen-acetylene flame, the device shown in Figure 3 can be used. Huangfu
Figure 3 Heating fixture device for oxygen-acetylene brazing test piece In order to adapt to the selected heating method, other clamping and adjustment devices can be selected. If the specimen is not heated as a whole (such as flame or induction heating), it must be ensured that the nail welding temperature is reached evenly within a range of 10 mm on both sides of the joint.
If flame or induction heating is used, the specimen should generally be heated to the brazing temperature in 40 to 60 seconds, and after the brazing material is melted, it should be kept for 10 to 30 seconds
2.5.3 The operating conditions should be listed in the test report. 2.6 Processing of specimens after brazing and the required number
The brazed specimens are processed into shear specimens and tensile specimens according to Figures 1 and 2. During processing, the strength properties of the brazed seam should not be affected. To determine the strength at room temperature or cold state, 5 specimens must be required, and to draw high temperature or creep strength curves, 5 to 10 specimens are required. 3 Strength test method
To avoid additional bending stress on the specimen, all tests are carried out on a fixture with adjustable fastening. The shear 113 test of the specimen in Figure 1
The test should be carried out on the fixture shown in Figure 4. #16
35
GB 8619-88
35
Figure 4 Tensile loading fixture
Both instantaneous shear and tensile tests are carried out on a tensile machine, and the loading speed and displacement speed should be adjusted to be equivalent to the characteristics of the test needle material.
Hot instantaneous shear specimens or tensile specimens should be placed on a tensile machine equipped with a furnace for loading. Before loading, the specimens should be kept warm for 1 hour, and the furnace temperature should be controlled within ± 1%.
The creep specimens should be carried out on a creep rupture machine. Before loading, the specimens should be kept warm for 1 hour, and the furnace temperature should be controlled within ± 1% (except for room temperature creep). The fracture surface should be inspected and the results should be recorded in the report. 4 Expression of results
Brazing joint strength (MPa) is equal to the breaking load (N) divided by the brazing joint area (mm2) 4.1 Room temperature instantaneous shear test and tensile test For each group of specimens, the average value x of the brazing joint strength must be calculated, and the following formula shall be used as the acceptance standard: 114
Wherein: Xi-
GB 8619--88
Brazing joint strength of each specimen (MPa)
—The sum of the brazing joint strengths of n specimens (MPa) Number of specimens:
—The minimum value of brazing joint strength (MPa) (guaranteed value proposed by the manufacturer) under the condition of given parent material and brazing filler metal. 4.2 Hot instantaneous shear test
The hot instantaneous shear test is used to determine the relationship curve between brazing joint strength (MPa) and temperature (℃). 4.3 Creep shear test
The creep shear test is used to determine the relationship between the fracture stress (MPa) of the needle seam and the creep failure time (h) at one or several temperature levels. The test stress is selected in the range of 0.1 to 103h according to the creep failure time. In special cases, the test stress should be selected within the creep failure time of 105 or 106h. Record
Table 1 Brazing joint strength test record
Test name
Test number
Base material brand (or main component)
Brazing filler material brand (or component)
Brazing flux brand (or main component)
Type and dosage of protective atmosphere (mL/min)Surface state and cleaning method of specimen brazing
Assembly gap of brazing joint (mm)
Heating method
Brazing temperature
Appearance of brazing joint after brazing
Record number
Main heating equipment
Time for heating to brazing temperature
( min)
Test date
Vacuum degree
Solder addition method
Heating time at pin welding temperature (min)
GB8619-88
Mechanical strength test results (ambient temperature, °C) Joint area
Tensile (shear) strength
(MPa)
(The creep shear test needs to record the test stress and rupture time. Then draw the relationship curve between the test stress and rupture time.) Filler
Additional remarks:
This standard was proposed by the State Machinery Industry Commission and is under the jurisdiction of Harbin Welding Research Institute. This standard was drafted by Harbin Institute of Technology. 116
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