This standard specifies the type, size, technical requirements, test methods and inspection rules of straight handle hook beam blanks. JB/T 7687.1-1995 Straight handle hook beam blanks JB/T7687.1-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Rough parts of straight shank hook beam
1 Subject content and scope of application
JB/T 7687.1--95
This standard specifies the types, dimensions, technical requirements, test methods and inspection rules of rough parts of straight shank hook beam. This standard is applicable to the die forged, free forged and rolled rough parts of straight shank hook beam on lifting machinery and equipment (hereinafter referred to as rough parts of beam).
Note: This standard should be used in conjunction with GB10051.1.GB10051-2, GB10051.4, GB10051.5 and JB/T7687.2 and JB/T7687.3. 2 Reference standards
GB 2975
Metal tensile test method
Steel mechanical and process performance test sampling points GB 10051. 1
Lifting hook mechanical properties, lifting capacity, stress and materials GB 10051.2
Lifting hook
GB 10051.4
Lifting hook
GB10051.5Lifting hook
GB12361
Steel die forgings
Technical conditions for straight shank hook
Rough parts of straight shank single hook
Straight shank single hook
General technical conditions
GB12362 Tolerances and machining allowances of steel die forgings GB/T13384 General technical conditions for packaging of electromechanical products JB/T7687.2 Straight shank hook beam
3 Strength grade of rough parts of beam
According to their mechanical properties, they are divided into 5 strength grades, which are the same as the strength grades of the matching lifting hooks, see GB10051.1 Chapter 3 Electricity Meter 1.
4 Classification
4.1 Type
4.1.1 Beam blanks are divided into the following three types according to their forging methods: a. Die forged beam blanks - generally used to manufacture beams with A-type hooks of 006~1, B-type hooks of 1.6~16 and C-type hooks of 2.5~40 in JB/T7687.2.
h. Free forging and rolling beam blanks
Beams in the hook device of the nut positioning plate. 4.1.2 Model indication method
Generally used for manufacturing C-type hooks No. 2.5 to No. 250 in JB/T7687.2 and hooks with hooks. Approved by the Ministry of Machinery Industry of the People's Republic of China on 1995-06-16 194
Implementation on 1996-07-01Www.bzxZ.net
4.1.3 Marking example
JB/T 7687.1--95
Strength grade: M, P, S, T, V
Hook number: 006 -~ 250
Forging method: die forging M, free forging Y, rolling Z beam rough parts
Hook number 006. Die forged hook beam rough parts with strength grade M should be marked as: beam rough parts HMM006-MJB/T7687.1 Hook number 40. Die forged hook beam rough parts with strength grade P should be marked as: beam rough parts HMM40-PJB/T7687.1
Hook number 100, free forging hook with strength grade M The rough parts of the crossbeam should be marked as: rough parts of crossbeam HMY100-MJB/T7687.1d.
Hook number 2.5, the rough parts of the rolled hook crossbeam with strength grade V should be marked as: rough parts of crossbeam HMZ2.5-VJB/T7687.14.2 Structural types and dimensions
4.2.1 The structural types and dimensions of the die-forged crossbeam rough parts are shown in Figure 1 and Table 1. 1) Center reference line
Note: () The slope is 7° if not noted.
1), the center should be on the reference line shown in the figure, and its value should make the outer contour from the beam journal to the beam center smooth and complete 195
010 and 012
020 and 025
04 and 05
08 and 1
145285
Note: 2 is not rounded.
JB/T 7687.1
Reference heavy
The structural type and size of the free forged and rolled beam blanks shall be determined according to the corresponding specifications and dimensions of the C-type straight handle hook beam in JB/T7687.24.2.2
Technical requirements
The beam blanks shall comply with the forging drawings and the requirements of this standard. 5.1
5.2 Materials
The materials used for the crossbeam blanks should match those of the hooks. The mechanical properties and chemical composition of the crossbeam blanks should comply with the requirements of GB10051.1. 5.3
Forging and heat treatment
The forging of the rough beam parts shall meet the following requirements. The forging ratio of the rough beam parts shall be in accordance with the provisions of Article 3.2.1 of GB10051.2: The dimensional tolerance and shape and position tolerance of the rough beam parts for die forging shall be determined in accordance with the relevant contents of Article 3.2 of GB12362: The tolerance of the rough beam parts for self-forging or rolling shall be negotiated by the supply and demand parties and in accordance with the provisions of the forging drawings; any type of rough beam parts is not allowed to be overburned. Overburned forgings must be scrapped. The heat treatment requirements for the rough beam parts are as follows. The heat treatment delivery status shall be indicated on the forging drawing: Normalizing or quenching and tempering: The number of heat treatments shall not be more than three times, but the number of tempering is unlimited. Surface and internal quality
JB/T 7687.1--95
5.4.1 The surface should be smooth and free from defects such as cracks and folds. 5.4.2 There should be no cracks, self-points or other defects that affect its safety in use. 5.4.3 Shot blasting or sand blasting is recommended for cleaning the surface oxide scale. 6 Test methods
6.1 The sampling for chemical analysis of materials shall comply with Article 4.1.1.1 of GB10051.2, and the chemical composition analysis shall comply with Article 4.1.1.2. 6.2 The tensile test for mechanical properties shall comply with the provisions of GB228: the impact test shall comply with Article 4.1.2.3 of GB10051.2. 7 Inspection rules
7.1 The inspection of rough parts of the crossbeam shall be carried out by the quality inspection department of the supplier (manufacturer) according to the forging drawings, technical agreements and this standard, and technical documents such as certificates of conformity shall be provided. || tt||7.2 Inspection items and quantity
The inspection items and quantity of rough beam parts shall be in accordance with the provisions of Table 2. Table 2
Mechanical properties
One piece shall be randomly inspected from each batch or tested with a test sample
Geometric dimensions
Die forgings: 10% random inspection. But not less than 3 pieces
Free forgings: 100%
Surface quality
Internal quality
When the height of the maximum cross section of the hook beam is greater than or equal to 1 50mm.
All forgings shall be subjected to ultrasonic testing
Note: Each batch refers to forgings with the same hook number, the same melting furnace number, the same heat treatment furnace and the same production batch. 7.3 The inspection position, sample cutting direction and quantity of each inspection item shall comply with the provisions of the forging drawing and special technical documents. 7.4 Judgment rules
When the first result of a test is unqualified, it shall be handled according to the following principles. 7.4.1 When white spots are found inside, all forgings of the melting furnace number shall be scrapped. 7.4.2 If overheating and breaking are found, it is allowed to re-heat treat and re-batch for acceptance. 7.4.3 If the mechanical properties are unqualified, it is allowed to take twice the number of samples for repeated testing. If ·· samples are unqualified during repeated testing, the batch of forgings is unqualified.
7.4.4 If other metallurgical defects are found, the supplier and the buyer shall negotiate to deal with them. 8 Marking and packaging
8.1 Clear marks should be made on the appropriate parts of the rough beam parts. For small forgings, it is not easy to have fixed marks. It is allowed to add labels or apply identification marks. The marking content is:
Supplier name or code (if necessary);
h. Hook;
Strength grade.
8.2 The packaging of rough beam parts shall comply with the relevant provisions of GB/T13384. The certificate of conformity and other random documents should be placed in the packaging box. The contents of the certificate of conformity are:
Supplier name or code;
Hook number:
Material brand:
Smelting furnace number;
Final conclusion of the chemical composition and mechanical properties test results of the forgings: Delivery status (normalizing or quenching and tempering):
Quantity;
Standard number.
JB/T 7687.1
Additional instructions:
This standard was proposed and managed by the Beijing Hoisting and Conveying Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Taiyuan Heavy Machinery Plant. The main drafters of this standard are Zhao Yonghua and Yan Shaoquan. 198
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