CB* 3095-1981 Rules for repair welding of civil copper alloy propellers
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National Ship Standardization Technical Committee Professional Standard CB?3095-81
Rules for Repairing Welding of Civil Copper Alloy Propellers
Published on March 4, 1982
Approved by the National Ship Standardization Technical Committee and implemented on January 1, 1983
National Ship Standardization Technical Committee Professional Standard Rules for Repairing Welding of Civil Copper Alloy Propellers
CB?3095-81
Group: 81
This rule applies to the repairing welding of casting defects or insufficient dimensions found in the manufacturing process of various civil ship copper alloy integral casting propellers. The repairing welding of combined propellers can also refer to this rule. The chemical composition and mechanical properties of the copper alloy used to manufacture propellers should comply with the provisions of CB818-80. Other copper alloy propellers can also refer to this rule. 1. Division of cup welding area and allowable defect range of repair welding When repairing the propeller, it is divided into five repair welding areas according to the location, size and degree of harm to the use of the propeller, A, B (B1, B.), C, D (D, D.), E (E1, E, E., E4) The division of the repair welding area and the allowable defect range of repair welding are shown in Figure 1 and Table 1. 30% blade surface near the edge
E, center of the research pole r0.4R 6,7R
Pressure surface
Repair welding area
Domain code
District and city division
Blade root center 0.4R
Suction surface
Schematic diagram of repair welding area
Division of repair welding area for copper-gold propeller of civil ships and range of defects allowed for repair welding The maximum size of a single defect allowed for repair welding is
100010005008004000m
Area S×depth h (mm*×mm)
Location of repair welding area
On the pressure surface, from the blade root:
Center to 0.4R,
But Excluding B, area
on the pressure surface from the blade root, center
B, room 0.4R, 30% of the blade width calculated from the trailing edge
on the pressure surface, the blade surface between 0.4R and
0.7R
on the suction surface, the blade surface from the blade root*center
to 0.4R
on the pressure surface, the blade surface from 0.7R to the blade end
on the suction surface, the blade surface from 0.4R to the blade end
E, the outer surface of the shaft
E, the inner surface of the shaft
E: the small end face of the hub
E. Shaft end face
Total defect area allowed for repair welding
1500mm
2500mm
4000mm
Only when the area and depth of a single defect are not greater than 70% of the maximum size of a single defect allowed in zone B, and the total defect area is not greater than 3% of the surface area of zone A, the manufacturer shall consult with the ship inspection department and relevant units, and obtain the consent of the ship inspection department, and on the premise of taking good repair welding technology and effective inspection and stress relief measures, allow the total repair welding in each zone
700×8
1400×7
1500×8
700×81500×8
700×8
1000×8
2500×10
2500×10
4000×10
2000×10
5000x15
5000×15
7500×15
7500×20
7500×1520000×25
4000×1510000×25
Note: ①The screw dimensions mentioned in the table are the net dimensions of the end rotation drawings, and d is the propeller diameter. ②The defect size refers to the size after the defect is eliminated ③The maximum length of a single defect allowed for repair welding shall not be less than 2V3 days. The National Technical Committee for Ship Standardization issued the following in 1982-03-04: The area should not exceed 5% of the area of the partition table, but when the total repair welding area on each surface (pressure surface or suction surface) is not greater than 5% of the area of the surface, the total repair welding area of D1 or D2 partition can be 7% of the surface area of the partition. The total area of repair welding for each partition shall not exceed 5% of the surface area of the partition. The total area of repair welding for each partition shall not exceed 10% of the surface area of the partition. Implementation on January 1, 1983 CB*3095-81 All defects allowed for repair welding in Table 1 shall be repaired under the guidance of the relevant technical departments of the manufacturer. When the defect size is larger than the size specified in Table 1, repair welding is not allowed in principle; however, for individual defects that do not exceed the specified size, the manufacturer may negotiate with the ship inspection department and relevant units for disposal. The number of repair welding for the same defect shall not exceed three times. 2 Repair welding process 2.1 Cleaning before welding a. Completely remove defects. On the premise of completely removing defects, the amount of metal for repair welding should be minimized. b. Process a groove suitable for repair welding, which should be smooth and free of burrs. C. For defects that are easy to spread during the repair welding process (such as cracks, etc.), measures should be taken to prevent the spread. d. Remove metal chips, oil stains, sand, water marks, oxides and all other dirt near the repair welding area; when welding multiple layers, they should be cleaned layer by layer.
2.2 Inspection
Check whether the defects are removed cleanly and whether the cleaning before welding meets the requirements. 2.3. Preheating
Perform according to the provisions of Chapter 3.
2.4 Repair weldingbZxz.net
Perform according to the provisions of Chapter 3.
2.5 Cleaning the weld
Remove the piled weld and grind it smooth. 2.6 Inspection
a. First conduct a visual inspection (you can use a magnifying glass), and then inspect it using the color flaw detection method. Any other defects with linear distribution and a size equal to or greater than 3mm should be repaired; defects with a size less than 3mm should be polished smooth. When the distance between two adjacent defects is less than three times the size of the smaller defect, the size of a single defect shall be used for calculation. b. For defects in areas A, B, C, E1, E., if the quality inspection department deems it necessary and possible, a radiographic or ultrasonic flaw detection inspection is required for acceptance reference.
c. The pitch and balance test shall comply with the requirements of the design drawings. 2.7 Heat treatment
Perform in accordance with the provisions of Chapter 3.
2.8 Inspection
Same as 2.6.
2.9 Records
During the repair welding, detailed records shall be made for the repair welding of each propeller, including the following items: a.
Ship name and ship owner;
Diameter, pitch, number of blades, material brand, furnace number or manufacturing number of the propeller; b.
Nature, location and size of the defect, and a schematic sketch; c.
Name of the welder and inspector, implementation of each process in the repair welding process and factory date; e.
Other items that are deemed necessary to be recorded.
The summary of the above records shall be shipped with the propeller. 3 Repair welding and post-weld stress relief treatment
3.1 It is recommended to use manual tungsten inert gas arc welding (automatic or semi-automatic argon arc welding can also be used) and arc welding for repair welding. Other repair welding methods that can ensure quality can also be used.
3.2ZHMn55-3-1 and ZHA167-5-2-2 gold-containing argon arc welding wire and arc welding electrode core are recommended to use the following composition: 60~2
CB*3095—81
62%Cu, 5.0~6.5%A1, 2~3%Mn, 2~3%Fe, the rest is Zn. The argon arc welding wire and arc welding electrode core of ZQA112-8-3-2 and ZQA114-8-3-2 alloys are recommended to use the following composition: 11.5~14.0%Mn, 7.0~8.5%A1, 2.53.5%Fe, 1.8~2.5%Ni, the rest is Cu. The diameter of the welding wire and welding core is 3.2~5.0mm. 3.3 Manual tungsten hydrogen arc welding generally uses AC, but DC can also be used when repairing ZHMn55-3-1 alloy. The diameter of the tungsten electrode is 4-6mm, and the diameter of the nozzle is 16-24mm. The flow rate of the shielding gas is 12-181/min. When welding ZHMn55-3-1 alloy, the flow rate of the shielding gas should be appropriately increased. Arc welding uses DC reverse connection. 3.4 For preheating before repair welding, it is recommended to use a far-infrared heater, or a soft gas flame or a ground furnace. The preheating temperature should pass through the entire cross-section of the repair welding area, and the preheating range should not be less than 100mm in all directions from the repair welding area. If possible, the preheating temperature should be slightly higher and should be maintained until the end of the repair welding.
3.5 All propellers that have been repaired must be subjected to post-weld stress relief treatment. For repair welding in areas A and B or large-area repair welding in other areas, it is recommended to use furnace annealing; in addition, local stress relief methods (such as local annealing and hammering) can be used: it is not allowed to spot weld or repair small defects at will without taking preheating, stress relief and other measures. 3.6 Before welding, hammer the welding groove area with a small head or pneumatic tool. After each weld of an appropriate length, hammer the weld and heat-affected zone. The hammering force should be appropriate, and the hammering points should be dense and evenly distributed. The preheating temperature and post-weld heat treatment specifications of various materials are shown in Table 2. Table 2 Preheating temperature and post-weld heat treatment specifications
Preheating temperature
Annealing temperature
Welder technical assessment
ZHMn55-3-1
150~350
300~400
ZHA1 67-5-2-2
150~250
500~550
ZQA112-8-3-2
ZQA114-8-3-2
100~250
450~550
Raise the temperature to annealing temperature at a heating rate of no more than 100℃/h, keep warm for 4 to 8 hours, then cool down with the furnace to below 200℃ at a cooling rate of no more than 50c/h, then open the furnace door for cooling Use far-infrared heater, soft gas flame, ground furnace, etc. to locally heat the repair weld to the ignition temperature. The number of minutes of insulation is greater than the number of millimeters of the cross-section thickness at that location, then cover with asbestos cloth for slow cooling 4.1 Welders who carry out propeller repair welding must undergo technical assessment, and only those who pass the assessment can weld. 4.2 Although qualified, welders who have interrupted the repair welding work for more than one year shall be required to pass the re-assessment before welding. 4.3 The welder assessment work shall be conducted by the repair welding unit. The assessment method is shown in the appendix of CB970-81. 4.4 When the relevant technical consulting department has a requirement, the welder shall be assessed according to the items specified by the department and must pass the assessment. Additional Notes:
This standard was drafted by 725 Institute.
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