This standard specifies the classification, requirements, test methods, inspection rules, marking, packaging, transportation and storage of zinc-aluminum-cadmium alloy sacrificial anodes. This standard applies to the design, manufacture, inspection, storage, etc. of sacrificial anodes for cathodic protection of metal components in electrolytes such as seawater, desalinated water, and soil with a temperature below 50°C and a resistivity less than 15Ω·m, including sacrificial anodes for cathodic protection of steel structures such as ships, port facilities, marine engineering, buried metal pipelines, storage tanks, and seawater cooling water systems. GB/T 4950-2002 Zinc-aluminum-cadmium alloy sacrificial anodes GB/T4950-2002 Standard download decompression password: www.bzxz.net

UDC 669.55*71*73 : 621.95.035.2 +548.06 National Standard of the People's Republic of China GB 4950~4951--85 Sacrificial anode of Zn - Al - Cd alloy and chemical analysis 1985-02-04 Issued 1985-10-01 Implementation National Standard Approved W. National Standard of the People's Republic of China Sacrificial anode of Zn -Al -Cd alloy UDC669.55'71 73 : 621.35 GB 4950-85
This standard applies to the zinc-lead alloy sacrificial anode (hereinafter referred to as sacrificial electrode) used for cathodic protection of seawater, desalinated water medium and parts, mechanical equipment (condensers, seawater pumps, etc.), marine and port facilities (drilling platforms, steel docks, water diversions, etc.) and slideways, pipelines, cables and other facilities in mud and soil medium. The use temperature is lower than 160℃; the dielectric constant is less than 1500·cm. 1. Terminology
1.1 Cathodic protection: A technology that allows direct current to pass through the protected metal to become the cathode in the electrochemical cell, thereby reducing the corrosion rate of the metal surface. 1.2 Sacrificial anode: In the electrolyte, a metal or alloy with a relatively negative electrode potential is connected to a metal structure with a relatively positive electrode potential, and the current generated by the former is used to protect the structure. This metal that is constantly corroded is called a sacrificial anode.
1.3. Theoretical current capacity: the electric current produced by the anode per unit mass of the anode according to Coulomb's law. Unit: Ah/kg. 1.4 Practical current capacity: the electric current produced by the anode per unit mass of the anode. Unit: Ah/kg.
1.5 Current efficiency: the percentage of actual capacitance and theoretical capacitance. 1.6 Reference electrode: the electrode with stable charge that can be used to measure the potential of other electrodes. 1.7 Open circuit potential: the natural potential of the anode in the electrolyte. Unit: V.
ta closed circuit potential: the electrode potential of the anode when the anode and cathode are short-circuited in the electrolyte. Unit: V. 2 Model specifications and main dimensions
2.1 Sacrificial medical general model specifications are shown in Table 1, Table 2, and Table 3. Table 1 Sacrificial anode model and specifications
Specifications, imm
ZAC:-C1 v
ZAC - C2
ZAC-C3V
Length () × width (B)> height (H)
41 100 × 35
4× 100×55
×150×50
National Bureau of Standards 1985-52-4 issued
Spiral set four regulations
α, kg
198510-01 implementation
W type
2AC-CS V
ZAC-- r6
ZAC C?
zaC- ta ​​Y
ZAC-C9
ZAC-J1
ZAC-J2
ZAC-JS
ZAC- J4
Z AC-J7
ZAC-HI
ZAC-H3
GB 495 0-85
Continued Table 1
Regulations. 1111
Fixed method
Length (L) × Width (B) × Height (H)
500 × 100 × 0
400 × 110 × 3
800 × 110 × 35
250 × 100 × 35
180 × 70 × 35
18u×× 12
Table 2 Anode model and specifications of mechanical equipment materials Specifications, mmbzxz.net
Length (L) × Width (B) × Diameter (D) × Height (H)
300 × 150 × 30
200 × 100 × 30
100 × 100 × 30
R0× 30×12
175×30
40×175
30 × 95
Fixed method
Spider thread fixed
Table 3 Models and specifications of anode plastics for marine engineering and port facilities, mm
[bottom()+bottom$×length()]
[115+ 135] × 1000 × 130
[115+135] × 750× 130
[113+135] × 500×130
Grid-section long strip
Reinforcement plate, kg
Head. kk
Mass, kg
WAuxiliary material, electrode structure, main material, size, see 1
GB4950-85
Figure 1ZAC-C1 sacrificial anode
27.AC-C2 sacrificial anode
W.Model specification
ZAC-C3
ZAC-JI
ZAC-J2
ZAC-C4
ZAC-C5
ZAC-C?
GB495Q85
C3, ZAC-J1, ZAC- J2 type sacrificial anode Figure 3 ZAC-
Iron core dimensions
ZAC-C~7.AC-C8 type sacrificial anode
Standard network iron core dimensions
GB495085
Figure 5 ZAC-C9 type sacrificial anode
Figure 6 ZAC-J3 type sacrificial cathode
W.GB4950--85
Iron core dimensions
Figure 7 ZAC-4 type sacrificial anode
Figure 8 ZAC-J5 type sacrificial anode
W type
ZAC- J6
GB4950—85
Figure 9 Structure of ZAC-J6, ZAC-J7 sacrificial anode Figure 6
W Model
ZAc,-H
ZAC-112
ZAC-H3
Spiral effect steel missing
GB495085
Word, xrm
Figure 10 ZAC-H type sacrificial electrode
20 --22
20 ~22
W2.3 type bow, ship grid description
$Raw materials
GB 4950-85
…Numbers represent specifications of anodes
Represents the purpose of anodes
C Marine anodes
1 Anodes for mechanical equipment
11 Anodes for marine engineering and port facilitiesRepresents the first added element
Aluminum-alloy
Represents the first added elementLead-
Represents zinc-based alloy
3.1 The purity of zinc shall not be lower than the provisions of %n-1 in Article 1.1 of GB470--83 "Zinc Ingot". 3.2 The purity of lead shall not be lower than the provisions of A1-00 in GB119675 "Aluminum Chain". 3.3 The purity of cadmium shall not be lower than the provisions of 1Cd-2 in 1CB914-66 "Cadmium Classification and Technical Conditions". 4 Technical conditions
3.1 Chemical composition
The chemical composition of the sacrificial anode shall comply with the requirements of Table 4. Table 4 Chemical composition of the sacrificial anode of the aluminum alloy. Maximum chemical element carbon content, %
0.05~0.12
4.2 Electrochemical properties of the sacrificial anode
The electrochemical properties of the sacrificial anode shall comply with the requirements of Table 5. 0.005
Table 5 Electrochemical properties of anode
Electrochemical properties
Open circuit
-1.05--1.09
1. Working potential
1.00 ~ -1:05
Theoretical capacitance
A+ h/kg
Method: Add water, electrode saturated with water: Actual capacitance
A·h/kg
Current efficiency
Dissolution performance
The bottom corrosion product is easy to fall off, and the surface dissolution is uniform
W4.3 Iron core
GB 4960--85
4.3.1 The steel core of the sacrificial anode shall be in accordance with the shape and size of the core in Figures 1, 2, 3, 4, 6, and 7 plus 7. The material of the steel shall comply with the provisions of GB912-82 "Technical Conditions for Thin Plates of Ordinary Carbon Structural Steel and Low-Alloy Structural Steel". 4.3.2 The core of the ZAC-H sacrificial anode shall be made of threaded steel with a diameter of 20 to 22 mm, and the material shall comply with the provisions of GB1499-79 "Heat Reinforced Steel Bars". The shape and size of the core are shown in Figure 10. 4.3.3 The surface of the sacrificial anode shall be galvanized, and the quality of the zinc layer shall meet the requirements of CB*744-83 "Quality Inspection of Electroplating and Chemical Coating". 4.4.1 The sacrificial anodes of the two specifications of ZAC-J1 and ZAC-J2 are processed with a rough surface, and the working surface of the sacrificial anodes of other specifications and types is a cast surface.
4.4.2 The working surface of the sacrificial anode shall be free of slag, hair tree, flash and crack, and the shrinkage cavity depth shall be less than t% of the thickness of the sacrificial anode.
4.4.3 The working surface of the sacrificial anode shall be kept clean and shall not be stained with paint or oil. 4.5 The contact resistance between the sacrificial anode matrix and the iron core The contact resistance between the sacrificial anode matrix and the iron core shall be less than 0.0012. 4.6 Metallographic structure of sacrificial anode
The metallographic structure of sacrificial anode is shown in Appendix A (reference). 5 Quality inspection
The production unit shall ensure the quality of the product and carry out product quality inspection. 5.1 Batch
The sacrificial anodes produced with the same batch of raw materials, the same process production line and the same shift are considered as a batch. 5.2 Chemical residue analysis
5.2.1 Randomly select three pieces from each batch of sacrificial anodes, and take more than 20g of scraps from each sacrificial anode as the analysis sample. The drill bit used for sampling should be cleaned thoroughly, and the sampling position should avoid the iron core. It is also possible to take samples from the front of different furnaces. 5.2.2 Perform analysis in accordance with GB4951-85 "Chemical Analysis Method for Zinc-Aluminum-Cadmium Alloy Sacrificial Anodes". The analysis results should comply with the provisions of Article 3.1 of this standard. If one sample is unqualified, double sacrificial anodes should be randomly selected for re-inspection. If there are still unqualified samples, the batch of sacrificial anodes shall not be used.
5.2.3 The sacrificial anodes after chemical analysis sampling will not affect their use and can be delivered together as products. 5.3 Appearance inspection
5.3.1 The surface quality of sacrificial anodes should comply with the provisions of Articles 4.4.2 and 4.4.3 of this standard. 5.3.2 The external dimensions of the sacrificial anode and the iron core shall comply with the provisions of the dimensions of the sacrificial anode in clauses 1 to 10 of this standard. 5.4 Test of contact resistance between the sacrificial anode substrate and the iron core 5.1 Three pieces of sacrificial anode are randomly selected as samples from every five vehicles to measure the contact resistance between the sacrificial anode substrate and the iron core. The results shall comply with the provisions of clause 4.5 of this standard.
5.4.2 The method for measuring the contact resistance between the sacrificial anode substrate and the iron core is shown in Appendix B. 5.5 Test of electrochemical performance
5.5.1 The production unit shall periodically test the electrochemical performance of the sacrificial anode, and the test results shall comply with the provisions of clause 4.2. If the user requires the electrochemical performance of the sacrificial anode to be provided, it shall be stated when placing an order. 5.5.2
5.5.3 See Appendix C of this standard for the test method. 6. Marking, storage, packaging and transportation
6. The upper surface of the sacrificial anode should be marked with model and specification, and the bottom surface of the sacrificial anode should be marked with production code and production batch number. The sacrificial anode should be stored in an indoor warehouse, and it is strictly forbidden to be contaminated with paint, oil and contact with chemical products such as acid, alkali and salt. 6.2
6. ZAC-C and ZAC-J sacrificial anodes should be placed in wooden pins reinforced with iron chains. The box should be printed with the name of the manufacturer and the model and specifications of the sacrificial anode in accordance with WGB 485085. The gross weight of each box is generally not more than 60kg. It can also be packaged and transported in the manner specified when ordering. 6.4 The box should be accompanied by a quality guarantee, which should include the batch number, batch tray, chemical analysis results and appearance inspection results of the sacrificial anode.
6.5During transportation, it is strictly forbidden to be contaminated with oil, paint, acid, alkali, salt and other chemical products. 11
W$ZAC-C, ZAC-J sacrificial anodes should be placed in wooden pins reinforced with iron chains. The box should be printed with the name of the manufacturer and the model and specifications of the sacrificial anodes in accordance with GB 485085. The gross weight of each box is generally not more than 60kg. It can also be packaged and transported in the manner specified when ordering. 6.4 A quality assurance certificate should be attached to the box. The content of the quality assurance certificate should include the batch number, batch tray, chemical analysis results, and appearance inspection results of the sacrificial anodes.
6.5 During transportation, it is strictly forbidden to be contaminated with oil, paint, and contact with chemical products such as acid, alkali, and salt. 11
W$ZAC-C, ZAC-J sacrificial anodes should be placed in wooden pins reinforced with iron chains. The box should be printed with the name of the manufacturer and the model and specifications of the sacrificial anodes in accordance with GB 485085. The gross weight of each box is generally not more than 60kg. It can also be packaged and transported in the manner specified when ordering. 6.4 A quality assurance certificate should be attached to the box. The content of the quality assurance certificate should include the batch number, batch tray, chemical analysis results, and appearance inspection results of the sacrificial anodes.
6.5 During transportation, it is strictly forbidden to be contaminated with oil, paint, and contact with chemical products such as acid, alkali, and salt. 11
W
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