This standard specifies the dimensions, appearance, technical requirements, test methods, acceptance rules, packaging, marking, quality certificates, etc. of continuous hot-dip aluminum-zinc-silicon alloy coated steel strips and steel plates. This standard applies to steel strips and steel plates with a nominal thickness of 0.25~2.50mm and a nominal width of 150~750mm. Steel plates are cut from steel strips. GB/T 14978-1994 Continuous hot-dip aluminum-zinc-silicon alloy coated steel strips and steel plates GB/T14978-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Continuous hot-dip aluminium zinc sillcenalloy coated steel strips and sheets1Subject content and scope of application
GB/T 14978—94
This standard specifies the size, shape, technical requirements, test methods, acceptance rules and packaging, marking quality certificates of continuous hot-dip aluminium zinc silicon alloy coated steel strips and sheets (hereinafter referred to as steel strips and sheets). This standard applies to steel strips and sheets with a nominal thickness of 0.25~~2.50mt1. Nominal width of 150~~750mtm. Steel plates are cut from steel strips.
2 Reference standards
GB228 Metal tensile test method
GB232 Metal bending test method
(B 247 Acceptance, packaging, marking and quality certificate of steel plates and strips: general provisions GB18398
Method for determining the plating load of galvanized steel plates (strips)
GB2975 Sampling regulations for mechanical and process performance tests of steel materials GB6397 Metal tensile test specimens
3 Definitions
3.1 Normal crystal flower: The coating produces regular A1, 711, Si under normal solidification conditions Surface structure of alloy body. 3.2 Chromic acid passivation: Acid passivation chemical treatment is performed on the surface of steel strips and steel plates to prevent white rust during transportation and storage. The anti-corrosion effect of chromic acid passivation is limited. If the steel strips or steel sheets are damp during transportation or storage, they should be dried or used immediately. 3.3 Oiling: Steel strips and steel plates can be oiled to reduce white rust. When the steel strips and steel plates are passivated, oiling will further reduce the harm of white rust.
4 Classification and Code
4.1 The categories and codes of products shall be in accordance with the provisions of Table 1. Table 1
Classification method
According to the performance
Classification approved by the State Technical Supervision Bureau on June 13, 1994
General purpose
Mechanical bite
Implementation on January 1, 1995
Classification method
Surface knot
According to surface treatment
According to dimensional accuracy
4.2 Marking example
GB/T 14978:94
Continued Table 1
Positive tape quality
Chromic acid passivation
Chromic acid passivation plus oiling
Commercial grade slight
Normal consistency
Coating weight is 200g/mAZ20), mechanical bonding (JY), surface chromic acid purification treatment (1.), dimensional accuracy is Class B, specifications are 0.50mm×320mm×1000mm plate, or 0.50mm×320mm strip, marked as: plate Az200-YLB-0.50×320X1 000-GB/T 14978-94 I; strip AZ200-JY-LB-0.50X 320-GB/T 14978-94 I5 Dimensions, shape and their allowable deviations
5.1 Dimensions and their allowable deviations
5.1.1 The nominal dimensions of steel strips and steel plates shall comply with the provisions of Table 2. Table 2
Note: ① If the purchaser has special requirements, the supply and demand shall be agreed upon. ② The requirements for the inner diameter after longitudinal shearing can be agreed upon by both parties. 5.1.2 The allowable deviations of the dimensions of steel strips and steel plates shall comply with the provisions of Table 3. Metric
0. 25 -~ 1. 00
Old inner diameter 450
15~750
1. 00~2. 50
Inner diameter of coil more than 01)
According to the order but more than 6 000
Note, D The distance between the thickness measuring part and the edge shall not be less than 20mmGB/T14978-94
Thickness allowable deviation (IJY, JG)
②The maximum thickness allowable deviation within 30m of the head and tail of the feather belt shall not exceed 50% of the value specified in Table 3③The maximum thickness allowable deviation within 20m of the welding zone of the feather belt shall not exceed 2% of the value specified in Table 3. ①According to the requirements of the purchaser, when supplying steel strips with intermediate specifications of nominal thickness in Table 3, the thickness allowable deviation shall be in accordance with the provisions of the adjacent small size. 5.7.3 The allowable deviation of the width of steel strips and steel plates shall comply with the provisions of Table 4. Table 4
Nominal width
150~750
High-grade precision A
Note: If the purchaser has higher requirements for the degree of precision, the effective party can agree to supply. 5.1.4 The allowable deviation of the length of steel plates shall comply with the provisions of Table 5. Table 5
Nominal length
High-grade precision A
5.2 Appearance
+0. 001 5×Nominal length
5.2.1 The maximum value of the insert bend of steel strips and steel plates shall comply with the provisions of Table 6. Width allowable tolerance
Ordinary precision B
Length allowable deviation
Ordinary alcohol content B
+ 0.003 0 × nominal length
GB/T14978-94
Maximum value
0.003X nominal length
5.2.2 The unevenness of steel plates and steel strips shall comply with the provisions of Table 7. Table?
Nominal width
150--750
Advanced precision A
0.70~1.20
Source length
Nominal length
Ordinary precision B
0. 70~-4.1, 20
5.2.3 The unevenness of steel strips is generally not measured. When the purchaser has requirements for unevenness, the unevenness index can refer to the steel plate index. 5.2.4 The cutting inclination of the steel plate should not be greater than 1%.
6 Technical requirements
6.1 Technical requirements for steel base
6.1.1 Steel grade and chemical composition
The grade and chemical composition are selected by the supplier. When the purchaser has requirements, the purchaser can also specify the grade or provide the chemical composition. 6. 1.2 Performance
The steel base is cold rolled strip. The steel base performance should comply with the provisions of Table 8. Table 8
180\Cold bending test
Additional performance
α, bend center diameter
a-test thickness
Tensile strength
270~500
Note: ① Steel cold bending test specimens are not allowed to have rust, cracks, fractures and delamination. ② Tensile test, the gauge length of the sample is 8 (m, width % 20mm. 6.2 Technical requirements for coating
6.2.1 Coating weight
Coating weight shall comply with the provisions of Table 9.
Combination point. .
Elongation
GB/T 14978-94
Three-point test average value
(double side) shall not be less than
Method: If the buyer has no specific requirements for the coating weight, supply shall be in accordance with A7.150. 6.2.2 Coating bend
Coating bend shall comply with Table 10 Regulations.
Three-point test value low value
180° bending test
d bend center diameter sample number
Note: The inlay layer is not allowed to fall off beyond 5mm from the edge of the sample, but cracks that do not expose the steel are allowed to appear on the surface. 6.2.3 Coating surface quality
The surface of the steel strip and steel plate should be smooth and flat, with uniform grain. Minor scratches, indentations and passivation spots are allowed. Small zinc particles and scars are allowed on the steel strip, as well as slight pitting caused by rust spots on the original steel strip. No missing plating spots are allowed on the steel plate.
6.2.4 Coating surface knots
The surface structure of the coating is normal grain:
6-2.5 Surface treatment of coating
The purchaser may select one of the following surface treatment methods: A. chromic acid passivation;
B. oiling;
C. chromic acid passivation plus oiling.
If the purchaser has no requirements, chromic acid passivation shall be applied. 7 Test methods
7.1 Measurement methods for size, shape and allowable deviation
7.1.1 The thickness of steel strips and steel plates shall be measured by ruler after hot dip coating. Width, length, camber, unevenness and cut slope shall be measured with a sample, caliper or ruler.
7.1.2 The camber measurement method of steel strips and steel plates shall be as shown in Figure 1. F Joint
CB/T 14978—94
Measurement length
7.1.3 Plate roughness measurement method: Place the steel plate on the platform and measure the maximum distance between the lower surface of the steel plate and the platform. The roughness of the saw blade is measured in accordance with the steel plate roughness measurement method. 7.1.4 The steel plate cutting slope measurement method is shown in Figure 2.
Cutting slope - Lu × 100%
7.2 Mechanical properties and .T. of steel strips and steel platesThe inspection of technical properties shall comply with the provisions of Table 11. Table 11
Inspection items
Tensile testbZxz.net
Cold test
Weight test
Plated bending test
Surface quality
Sampling force method
GI 2975,GB 6397
GB 2975,G 6397
GR 2975,GB 6397
Test method
CrH1839
G13232
Test after removing the plating layer
Test after removing the plating layer
Test area 50:m
Note, ① In the sampling method of the layer density test, if the steel thickness is greater than or equal to 250mm1, three samples are taken at equal distances in the width direction of the strip steel. If the steel thickness is less than 250mm, take 1 sample longitudinally on the center line of the strip length, and the sample interval is 50mm. Figure Tensile, cold bending, bending test samples are all one piece. 8 Inspection rules
8.1 Batch
GB/T 14978-94
Steel strips and steel plates should be accepted in batches. Each batch consists of steel strips or steel plates with the same brand, the same coating weight, the same processing performance, the same size, and the same surface treatment state. Each batch of steel plates shall not exceed 10t, and each coil of steel strip shall be a batch. Take one sheet from each batch of steel plates, and each coil of steel strip shall be a batch. Take one sheet from each batch of steel plates at random, and cut one sheet from the head or tail of each coil of steel strip for inspection. 8.2 Re-inspection
The re-inspection rules for strips and steel plates shall comply with the provisions of GB 247. 9 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel strips and steel plates shall comply with the provisions of GB247. Additional remarks#
This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard is under the jurisdiction of the Information Standards Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Iron and Steel Research Institute of the Ministry of Metallurgical Industry, Jiangsu Changshu Cold Rolled Strip Steel General Plant, and Jiangsu Zhangjiagang Wuyuan Steel Products Co., Ltd.
The main drafters of this standard are Li Lingyun, Zhang Guanghong, Su Jianqing, Xu Ruizhong, Lu Jianping, and Xu Wancui. This standard level mark
GB/T 14978—94 T
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