This standard specifies the main inspection items and test methods for high-strength bolts for construction machinery. This standard applies to high-strength bolts for construction machinery with performance grades of 8.8, 10.9 and 12.9. JB/T 7150-1993 Main inspection items and test methods for high-strength bolts for construction machinery JB/T7150-1993 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T 7150-93
High-strength bolts for construction machinery
Main inspection items and test methods
Published on November 21, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on March 1, 1994
Machinery Industry Standard of the People's Republic of China
High-strength bolts for construction machinery
Main inspection items and test methods
1 Subject content and scope of application
This standard specifies the main inspection items and test methods for high-strength bolts for construction machinery. This standard is applicable to high-strength bolts for construction machinery with performance grades of 8.8, 10.9 and 12.9. 2 Reference standards
GB1214
GB1216
GB1219
GB1957
GB2928
GB 3934
GB5267
GB5617
GB6315
GB9054
JBJ04006
Names of screw parts
Vernier caliper
Outside micrometer
Dial indicator
Smooth limit gauge
Projector
Mechanical properties of fasteners Bolts, screws and studs Common thread gauge
Threaded fasteners Electroplating layer
Determination of effective hardened layer depth after induction quenching or flame quenching of steel Surface defects of fasteners - Bolts, Screws and studs - general requirements Universal angle ruler
Radius template
Magnetic particle inspection method for steel materials
The names of the parts of the bolt are shown in the figure below and Table 1,
Approved by the Ministry of Machinery Industry on November 21, 1993
JB/T7150-93
Implementation on March 1, 1994
Head bearing surface
Corner of the figure
Matching rod surface
Elastic part of the rod
Screw end
Split pin hole
Main inspection items and inspection methods
JB/T 7150~93
Thread end
Position of the axis centerline of the split pin hole to the axis line of the screw Potential effective length 6
Distance from the auxiliary centerline of the split pin to the head bearing surface, nominal length!
Tightening dimensions (head height K, width across flats S, diagonal width e)
Main inspection items and testing methods for high-strength bolts for engineering machinery shall be in accordance with the provisions of Table 2. During arbitration, method 1 shall prevail. Table 2
Inspection items
Tensile strength
a. Bolt head hardness:
b. Bolt support
c. Bolt core hardness
Guaranteed load
Mould negative comparison
Impact test
Thread decarburization layer
Each material shall be tested once, and repeated testing shall be carried out in special circumstances. The material shall be selected by the manufacturer, but must meet the requirements of the corresponding material mechanical properties and implement the relevant provisions of Article 8.2 of GB3098.1. Within the corresponding tensile strength requirements of the bolt, no fracture is allowed to occur and implement the relevant provisions of Article 8.3 of GB3098.1. Track bolt head hardness inspection position (as shown in the figure) National
The hardness of the bolt core refers to the hardness measured at R/2 from the thread surface (as shown in the figure)
Implement the relevant provisions of Article 8.4 of GB3098.1 Implement the relevant provisions of Article 8.5 of GB3098.1, the position of the screw should be at the screw effect, the necking should be obvious after fracture, the shape of the fracture should be close to 45*, and the fillet under the head is not allowed to break. Implement the relevant provisions of Article 8.6 of GB3098.1 According to the decarburization requirements of performance grade 10.9 in Table 3 of GB3098.1 and the relevant provisions of Article 8.8 test methods, implement the relevant provisions of ZBJ04006.
Connecting rod screw inspection parts inspection
Name of inspection tool
Colorimeter
Universal material testing machine
Hardness tester
Universal material testing machine
Chain-type impact testing machine
Microscope
Hardness tester
Magnetic particle flaw detector
Inspection items
Hard layer depth of track bolt head
Major thread diameter
Thread accuracy
Thread length b
b. Clamp length 1
JB/T7150-93
Continued Table 2
Implement the relevant provisions of GB5617,
When the thread diameter is less than or equal to M12, the hard layer depth is 3~5mm, and when it is greater than M12, it is 4~7mm.
The depth of the zinc hard layer should be evenly distributed, and there should be no valve tilt and instability. The sampling position is shown in the figure.
There are 2 threads at the end of the thread and the end of the screw. Detection method 1:
Use an outside micrometer to measure in any two mutually perpendicular diameter directions of the test position.
Method 2:
Use a through-end smooth caliper to clamp the bolt thread, which should be able to pass smoothly. Use a stop-end smooth caliper to clamp the bolt thread, which should not pass through the through-end blasting blasting ring gauge: It should be able to enter freely by hand force. The number of passing buckles of the stop effect ring gauge cannot exceed the total number of buckles of the stop end ring gauge (generally not more than 2 buckles), and the edge line of the pin hole must be visible for the bolt with a pin hole on the rod.
8. According to the provisions of GB5267: the position of the tolerance zone of the media thread before the chain is g, j or e+, and only 6h or 8h grade end thread gauge is used for detection after the chain: b. If the burst thread gauge judged to be qualified is in accordance with the provisions of GB3934, the thread should be judged to be qualified
a. Use a caliper with an accuracy of 0.05mm to measure from the end of the screw to the end face of the through thread ring gauge (as shown in the figure). b. Measure the distance from the support surface (or the intersection of the support surface and the explosion rod) to the end of the through-end thread ring gauge (as shown in the figure)Thread ring gauge
Name of inspection tool
Hardness tester
Thousands specified in GB1216
Through and stop end caliper gauge specified in GB3934
Frequency ring gauge
Card gauge specified in GB1214
Through and stop end caliper gauge specified in GB3934
Comprehensive thread ring gauge
Inspection items
Nominal length!
Screw size
a.Head height K:
b.Across-side width s
c.Diagonal width.
Head lower angle radius
Matching rod diameter
Elastic part of rod
Degree of maturity of bolt head to bolt rod
JB/T715093
Continued Table 2
Based on the short side, use a caliper with an accuracy of 0.05mm to measure the distance from the end of the table rod to the head support
Measure with a caliper with an accuracy of 0.02mm at the maximum size Method 1:
Side measurement with a projector
Method 2:| |tt||Measure with a special radius template
The cylindrical tolerance value should be less than 1/2 of the size tolerance value. Method 1,
Measure with a caliper with an accuracy of 0.02mm
Method 2:
Measure with a special through and stop gauge
Measure with a caliper with an accuracy of 0.05mm
The reference surface should be one of the threaded part surface, the matching rod surface or the rod elastic part surface, and should not be composed of any of the above two parts, and should be selected as close to the head support surface as possible. The reference surface should avoid the fillet under the head and the explosive effect collection end 2 loss buckle
Method 1:
a.For hexagonal head and square head: place the bolt on the V-shaped frame and rotate it (no axial movement is allowed), move the probe of the dial indicator, measure the minimum reading value of each wrench surface, calculate the difference between each pair of plane readings, and take the maximum value (as shown in the figure),
Mass point text
V-shaped frame
b, for drawing head, etc., identify the bolt on the V-shaped frame and rotate it (no axial movement is allowed), use the dial indicator to measure, and measure the pointer reading value. The maximum difference of the inspection tool name
Card specified in GB1214
Throw specified in GB2928
GB 9054 specified radius sample
GB1214 specified caliper
GB1957 specified caliper
GB1214 specified caliper
GB1219 specified vernier gauge and special V-shaped frame
Inspection items
Coaxiality of bolt head to bolt rod
Verticality of the axis of the head support facing the rod
Bolt straightness
Method 2:
JB/T 715093
Continued Table 2
First measure the minimum height value between each line of the screw and the wrench surface or outer circle with a caliper with an accuracy of 0.02mm; then measure the height value in the relative direction, and the difference between the two is the measured value
The selection of measurement basis is the same as that of No. 18 in this table. The measuring circumference should be 0.8 mm, the width of opposite sides is 5 mm or the diameter of the head of the cylindrical bolt. Method 1: Place the end bolt on the V-shaped frame and rotate it (no axial movement is allowed). Use a dial indicator to measure the maximum difference in the pointer reading (as shown in the figure). The measuring circumference of the scene. Point support. V-shaped frame. Method 2: Use a special fixture with a chuck and a dial indicator to measure. The selection of the measurement basis is the same as No. 18 in this table. Method 1: Place the end bolt on the V-shaped frame, use a dial indicator to measure at the large curved part, rotate the bolt one circle, measure the maximum difference in the pointer reading, and take 1/2 of it as the fixed value (as shown in the figure). Total large part. Black dot bearing. Method 2: Screw the media rod into the special inspection mold with internal media by hand. In the middle, it should be able to screw into Figure 2 and above (calculated from the control and withdrawal explosion rod) (as shown in the figure) Metal inspection structure
Method 3:
Put the medium inspection into the special inspection mold by hand, and it should be able to rotate 360° freely
Name of inspection tool
Card specified in GB1214
Hundred meter and special V-shaped frame specified in GB1219
Hundred meter and special inspection tool specified in GB1219
Hundred meter and special V-shaped frame specified in GB1219
Method 2:
Special inspection mold, its aperture
Special inspection mold, its grid width
Inspection items
Diameter of cotter pin hole
Symmetry of cotter pin hole to the axis
Line of rod
Cotter pin hole Position of the axis to the screw axis
Distance from the axis of the cotter pin hole to the head bearing surface
Surface roughness
a. The fillet under the head and the head bearing surface:
b. The weakening surface of the bolt rodbzxz.net
c. The side surface of the thread
Method 1:
JB/T7150—93||t t||Continued Table 2
Measure with a caliper with an accuracy of 0.02mm
Method 2
The standard pin should be able to be inserted into the cotter pin hole (as shown in the figure in No. 22 of this table)
Method 1:
Measure along the diameter direction with a caliper with an accuracy of 0.02mmMethod 2:
Insert the screw into the special screw effect ring gauge, and the pin should be able to be inserted into the open auxiliary hole (as shown in the figure)
Thread ring line
Method 1:
First insert the special pin into the cotter pin hole, then place it on the projector, and measure the deviation value of the two intersection points of the projection line on the same side of the special pin and the screw (as shown in the figure)
Measure with a universal angle ruler and a special pin ladderName of the inspection tool
The standard pin tower specified in GB1214 has a diameter of 4
equal to the parallel port The minimum limit size of the pin hole is the special groove ring gauge and standard pin selection specified in GB1214. The cumulative groove of the special groove ring is equal to the minimum limit size of the cotter pin hole with the same standard groove diameter 4; the groove width of the ring gauge is S,-d, +
Projector and special pin specified in GB2928, the diameter of the special pin is .d.
Universal angle ruler and special pin specified in GB6315
Measure with 0.02mm precision caliper
Compare with surface roughness comparison sample block Visual inspection with surface roughness comparison sample block specified in GB1214
Inspection items
Surface anti-rust treatment||tt| |Surface defects
Final metallographic comparison and metal
Metal fiber streamlines
Additional notes:
JB/T7150--93
Continued Table 2
Visual inspection, implement the relevant provisions of GB5779.1. If the coating or chain layer affects the identification of surface defects, the coating or plating should be removed before testing
A longitudinal surface is cut along the center line of the bolt, installed on the tool or connected to the visual material, and then illuminated until the metallographic comparison test can be carried out. Use a microscope to avoid comparison tests, and check the metal fiber streamlines at the same time. The macroscopic fiber texture of the bolt should be clear, and the transition between the bolt and the metal fiber should be smooth. This standard was proposed and coordinated by the Tianjin Engineering Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Tianjin Engineering Machinery Research Institute and Chaobei Yangxin Machinery Factory. The main drafters of this standard are Shang Haibo and Yu Shuiying, and their names are Cheng
Microscope0.2mm precision caliper for measurement
Method 2
The standard pin should be able to be inserted into the cotter pin hole (as shown in the figure in No. 22 of this table)
Method 1:
Measure along the diameter direction with a 0.02mm precision caliperMethod 2:
Insert the screw into the special screw effect ring gauge, and the pin should be able to be inserted into the open auxiliary hole (as shown in the figure)
Thread ring line
Method 1:
First insert the special pin into the cotter pin hole, then place it on the projector, and measure the deviation value of the two intersection points of the projection line on the same side of the special pin and the screw (as shown in the figure)|| tt||Use universal angle ruler and special pin ladder to measure. Name of the inspection tool. The diameter of the standard pin ladder specified in GB1214 is equal to the minimum limit size of the cotter pin hole. The special groove ring gauge and standard pin specified in GB1214 are selected. The cumulative groove of the special groove ring is equal to the minimum limit size of the cotter pin hole with the same diameter of the standard pin ladder; the groove width of the ring gauge is S,-d, +
Projector and special pin specified in GB2928, the diameter of the special pin is .d.
Universal angle ruler and special pin specified in GB6315
Measure with 0.02mm precision caliper
Compare with surface roughness comparison sample block Visual inspection with surface roughness comparison sample block specified in GB1214
Inspection items
Surface anti-rust treatment||tt| |Surface defects
Final metallographic comparison and metal
Metal fiber streamlines
Additional notes:
JB/T7150--93
Continued Table 2
Visual inspection, implement the relevant provisions of GB5779.1. If the coating or chain layer affects the identification of surface defects, the coating or plating should be removed before testing
A longitudinal surface is cut along the center line of the bolt, installed on the tool or connected to the visual material, and then illuminated until the metallographic comparison test can be carried out. Use a microscope to avoid comparison tests, and check the metal fiber streamlines at the same time. The macroscopic fiber texture of the bolt should be clear, and the transition between the bolt and the metal fiber should be smooth. This standard was proposed and coordinated by the Tianjin Engineering Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Tianjin Engineering Machinery Research Institute and Chaobei Yangxin Machinery Factory. The main drafters of this standard are Shang Haibo and Yu Shuiying, and their names are Cheng
Microscope0.2mm precision caliper for measurement
Method 2
The standard pin should be able to be inserted into the cotter pin hole (as shown in the figure in No. 22 of this table)
Method 1:
Measure along the diameter direction with a 0.02mm precision caliperMethod 2:
Insert the screw into the special screw effect ring gauge, and the pin should be able to be inserted into the open auxiliary hole (as shown in the figure)
Thread ring line
Method 1:
First insert the special pin into the cotter pin hole, then place it on the projector, and measure the deviation value of the two intersection points of the projection line on the same side of the special pin and the screw (as shown in the figure)|| tt||Use universal angle ruler and special pin ladder to measure. Name of the inspection tool. The diameter of the standard pin ladder specified in GB1214 is equal to the minimum limit size of the cotter pin hole. The special groove ring gauge and standard pin specified in GB1214 are selected. The cumulative groove of the special groove ring is equal to the minimum limit size of the cotter pin hole with the same diameter of the standard pin ladder; the groove width of the ring gauge is S,-d, +
Projector and special pin specified in GB2928, the diameter of the special pin is .d.
Universal angle ruler and special pin specified in GB6315
Measure with 0.02mm precision caliper
Compare with surface roughness comparison sample block Visual inspection with surface roughness comparison sample block specified in GB1214
Inspection items
Surface anti-rust treatment||tt| |Surface defects
Final metallographic comparison and metal
Metal fiber streamlines
Additional notes:
JB/T7150--93
Continued Table 2
Visual inspection, implement the relevant provisions of GB5779.1. If the coating or chain layer affects the identification of surface defects, the coating or plating should be removed before testing
A longitudinal surface is cut along the center line of the bolt, installed on the tool or connected to the visual material, and then illuminated until the metallographic comparison test can be carried out. Use a microscope to avoid comparison tests, and check the metal fiber streamlines at the same time. The macroscopic fiber texture of the bolt should be clear, and the transition between the bolt and the metal fiber should be smooth. This standard was proposed and coordinated by the Tianjin Engineering Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Tianjin Engineering Machinery Research Institute and Chaobei Yangxin Machinery Factory. The main drafters of this standard are Shang Haibo and Yu Shuiying, and their names are Cheng
Microscope
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