This standard specifies the dimensions, shape, technical requirements, test methods, inspection rules, etc. of hot-rolled steel plates for automobile beams (longitudinal beams and cross beams). This standard is applicable to the manufacture of low-alloy hot-rolled steel plates with a thickness of 2.5~12mm for automobile beams. GB/T 3273-1989 Hot-rolled steel plates for automobile beams GB/T3273-1989 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Hot-rolled steel plates and sheetsfor automobile girders
Hot-rolled steel plates and sheetsfor automobile girders
1 Subject content and scope of application
GB 3273--89
Replaces GB373-82
This standard specifies the dimensions, appearance, technical requirements, test methods, inspection rules, etc. of hot-rolled steel plates for automobile girders (longitudinal beams and cross beams). This standard is applicable to low-alloy hot-rolled steel plates with a thickness of 2.5 to 12 mm for making road automobile girders. 2 Reference standards
GB222 Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products GB223 Chemical analysis methods for steel and alloys
Metal tensile test method
Metal bending test method
GB 247
General provisions for acceptance, packaging, marking and quality certification of steel plates and strips GB709
Dimensions, shape, weight and permissible deviations of hot-rolled steel plates and strips GBE591
GB 2975
GB 6394
GB6397
Low-alloy structural steels
Sampling provisions for mechanical and process properties tests of steels Method for determining the average grain size of metals
Metal tensile test specimens
Method for evaluating the microstructure of steel (free cementite, banded structure and Widmanstatten structure) 3 Terms and symbols
3.1 Steel plates are supplied in flat form and can be directly rolled or cut from wide steel strips. L represents the steel used for automobile weaving and cross beams.
4 Size, shape
4.1 Size
4.1.1 Size range of steel plate
Thickness: 2.5 ~ 12.9 mm
Width: 210~1300mm
Length: 2000~10000mm
4.1.2 The size of the supplied steel plate (including fixed length and custom length) shall be requested by the purchaser and shall be indicated in the contract. 4.1.3 According to the purchaser's requirements, after agreement between the supply and demand parties, steel plates outside the above size range may be supplied. 4.2 Thickness allowable deviation
4.2.1 The thickness allowable deviation of the boiler plate shall comply with the provisions of Table 1. Approved by the Ministry of Metallurgical Industry of the People's Republic of China on February 16, 1989 and implemented on January 1, 1990
G8 3273-89
4.2.2 Based on the requirements of the purchaser, positive and negative deviations may be adjusted within the tolerance band. Table 1
2. 5 ~ 3. 5
>8. 5 ~ 4. 5
>4. 5 ~ 6. 0
>6. 0 ~7. 5
>7. 5 ~ 9. 5bzxZ.net
>9. 5 ~ 12. 5
4.3 Allowable deviation of width and length
≥1 250 ~ 1 60
— 0. 25
— 0. 50
The allowable deviation of width and length of steel plates shall conform to the relevant provisions of GB 709. 4.4 Appearance
4.4.1 Roughness
The roughness of steel plates shall conform to the relevant provisions of G8709. 4.4.2 Camber
The total camber of the steel plate delivered in the rolled state without trimming shall meet the following requirements: Length: 2000~4000mm
>4 000~7 000 mm
27 000 mm
4.4.3 Cutting slope
Total camber ≤12mm
Total cutting slope ≤22 mm
Total camber ≤26mm
>1 600
For the steel plate delivered after trimming, the cutting slope shall not exceed the allowable deviation of the length and width of the steel plate, and the minimum rectangle of the nominal size shall be ensured. 5 Technical requirements
5.1 Grade and chemical composition
5.1.1 The grade and chemical composition of the steel shall meet the requirements of 2. Under the condition of ensuring performance, the lower limit of carbon, silicon and manganese content may not be assessed for delivery conditions.
5.1.2 The residual element content in steel shall comply with the provisions of GB1591. 5:1.3 The allowable deviation of the chemical composition of the finished steel plate shall comply with the provisions of Table 1 of GB222. 5.1.4 The analysis results of rare earth (RE) shall be filled in the quality certificate. 5.2 Delivery status
5.2.T The steel plate shall be delivered in the hot-rolled state or heat-treated state after pickling and oiling. With the agreement of the supply and demand parties, the steel plate may also be delivered without pickling, but the positive and negative deviations of the steel thickness shall leave a larger washing margin of 0.1 mm. 5.2.2 The steel plate shall be delivered with the four sides cut, but the single-length steel strip with a direct rolling width of less than 600mm may be delivered without cutting the longitudinal edge. Guide
O9MnREL
16MnREL
5.3 Mechanical properties and process properties
GE 3273-89
Chemical composition, %
5.3.1 The mechanical properties and process properties of the steel plate shall comply with the provisions of Table 3. 5.4 High power inspection
5.4, 1 The grain size of the steel plate shall be 6 to 11 levels, and its adjacent levels shall not exceed three levels. 5.4.2 The banded structure of the steel plate shall not be greater than 2 levels. Steel plates greater than 2 to 3 levels can also be delivered. 3
Cancer service strength α
09MnREL
09sIVL
16MnREL
2. 5 ~ 12. 0
2. 5 ~ 12. 0
5. 0~7. 0
2. 5~ 7. 0
>7. 0~12. 0
2. 5 ~ 7. 0
>7. D ~ 12. 0
Note: It is the width of the cold specimen.
not less than
tensile strength b
375~470
375~ 480
390~~510
510630
510~610
510~610
510-610
510~610
510~610
Elongation.
Not less than
Additional amount
Cold bending 180
A-Test specimen thickness
b±35mm
d-Bending center diameter
± = 0. 5d
5.5Surface quality
The surface of the steel plate shall not have cracks, bubbles, inclusions, scars, folds and obvious scratches. The steel plate shall not have delamination. If there are the above defects on the surface of the steel plate, it is allowed to clean up, and the cleaning depth shall not exceed half of the allowable tolerance of the steel plate thickness. Other defects are allowed to exist, and their depth or height shall not exceed half of the allowable tolerance of the steel plate thickness.
6 Test method
6:1 Direction of tensile test specimen
GB3273—89
When the plate width is less than 600mm, the specimen shall be taken along the rolling direction; when the plate width is equal to or greater than 600mm, the specimen shall be taken perpendicular to the rolling direction.
6.2 The number of specimens, sampling method and test method for each batch of steel plates shall comply with the requirements of Table 4. Table 4 Inspection rules Test neck Chemical composition Product particle size Banded structure Test number, pcs 1 (furnace number) Suction sampling method GB 222 GB2975 GB2975 Test method GB6397 Test sample P4 or GB8228 GB6394 7.1 Steel plates shall be inspected in batches. Each batch shall consist of steel plates with the same rolling system and heat treatment system (referring to heat-treated steel plates).
7.2 Other inspection rules for steel plates shall be in accordance with GB 247. Packaging, marking and quality certificates
The packaging, marking and quality certificates of steel plates shall comply with the provisions of GB247. Additional remarks:
This standard was proposed by the Information Standard Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Fourth Steel Plant of Changcheng Special Steel Company, the Third Steel Plant of Shanghai, and the Information Standard Research Institute of the Ministry of Metallurgical Industry. The main drafters of this standard are Ning Jie, Ran Shaowu and Tang Fan. This standard is marked with GB 3273--89 Y
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