GB/T 36233-2018Tubular cored electrodes for high-strength steels (English PDF)

3.1 Model division

The wire type is based on the mechanical properties of the deposited metal, the use characteristics, the welding position, the type of protective gas, the state after welding and the chemical composition of the deposited metal.

Wait for division. Refer to Appendix C for the comparison of this standard with other related standards for flux cored wire.

3.2 Model preparation method

The wire type consists of eight parts.

1) Part 1. The fuse "wire" is indicated by the letter "T";

2) The second part. indicates the tensile strength code of the deposited metal, see Table 1;

3) The third part. the test temperature code indicating that the impact energy (KV2) is not less than 27J, see Table 2;

4) Part 4. Indicates the use of the feature code, see Table 3;

5) Part 5. indicates the welding position code, see Table 4;

6) Part 6. Indicates the type of protective gas type, the code for self-protection is "N", and the code for protective gas is in accordance with ISO 14175.

See Appendix D;

7) Section 7. Indicates the post-weld status code, where "A" indicates the weld state, "P" indicates the post-weld heat treatment state, and "AP" indicates the weld state and

Both states of post-weld heat treatment can be used;

8) Section 8. Indicates the chemical composition of deposited metal, see 4.3, and Appendix E for the classification.

In addition to the above mandatory code, an optional code can be appended to it.

a) the letter "U" indicates that the shock absorption energy (KV2) should not be less than 47J at the specified test temperature;

b) Diffusion hydrogen code "HX", where "X" may be the number 15, 10 or 5, representing the diffusible hydrogen content per 100 g of deposited metal

Maximum value (mL), see 4.6.

The wire type examples in this standard are as follows.

Example 1.

Flux cored wire

Indicates the tensile strength of the deposited metal, and "69" indicates a minimum of 690 MPa.

Indicates that the impact absorption energy (KV2) is not less than the test temperature at 27 J, and "4" means -40 °C.

T5-

Indicates the use characteristics, "T5" indicates that the core type is calcium oxide-fluoride, using DC reverse connection, coarse drop transition, etc.

Indicates the welding position, "0" indicates the flat welding and the fillet welding position

C1

Indicates the type of shielding gas, "C1" indicates that the gas composition is 100% CO2

Indicates post-weld condition, "P" indicates post-weld heat treatment

4M2

Indicates the chemical composition of deposited metal

Example 2.

Flux cored wire

Indicates the tensile strength of the deposited metal, and "69" indicates a minimum of 690 MPa.

Indicates that the impact absorption energy (KV2) is not less than the test temperature at 27 J, and "5" indicates -50 °C.

T5-

Indicates the use characteristics, "T5" indicates that the core type is calcium oxide-fluoride, using DC

Reverse connection, coarse transfer, etc.

Indicates the welding position, "1" indicates the full position

M21

Indicates the type of protective gas, "M21" means the gas composition is (15%) \u003cCO2<=25%) Ar

Indicates the post-weld state, "A" indicates the as-welded state

N3M1

Indicates the chemical composition of deposited metal

Optional additional code indicating the shock absorption energy (KV2) at the specified test temperature

Not less than 47J

H5

Optional additional code means that the diffused hydrogen content of the deposited metal is not more than 5mL/100g

Example 3.

Flux cored wire

Indicates the tensile strength of the deposited metal, and "62" indicates a minimum of 620 MPa.

Indicates that the shock absorption energy (KV2) is not less than the test temperature at 27 J, and "3" indicates -30 °C.

T8-

Indicates the use characteristics, "T8" indicates that the type of core is not specified, using DC positive connection, fine droplets or

Jet transition, etc.

Indicates the welding position, "1" indicates the full position

Indicates the type of protective gas, "N" indicates self-protection

Indicates the post-weld state, "A" indicates the as-welded state

N2

Indicates the chemical composition of deposited metal

H5

Optional additional code means that the diffused hydrogen content of the deposited metal is not more than 5mL/100g

Example 4.

Flux cored wire

Indicates the tensile strength of the deposited metal, and "83" indicates a minimum of 830 MPa.

Indicates that the impact absorption energy (KV2) is not less than the test temperature at 27 J, and "5" indicates -50 °C.

T15-

Indicates the use characteristics, "T15" indicates that the core type is metal powder type, and DC reverse connection is used.

Fine droplet ejection transition, etc.

Indicates the welding position, "1" indicates the full position

M20

Indicates the type of shielding gas, "M20" means the composition of the gas is (5% \u003cCO2<=15%) Ar

Indicates the post-weld state, "A" indicates the as-welded state

N3C1M2

Indicates the chemical composition of deposited metal

H5

Optional additional code means that the diffused hydrogen content of the deposited metal is not more than 5mL/100g

Table 1 deposited metal tensile strength code

Tensile strength code

Tensile strength Rm

MPa

Yield strength aReL

MPa

Elongation after break A

59 590~790 >=490 >=16

62 620~820 >=530 >=15

69 690~890 >=600 >=14

76 760~960 >=680 >=13

78 780~980 >=680 >=13

83 830~1030 >=745 >=12

a When the yield is not obvious, the specified plastic elongation strength Rp0.2 should be determined.

Table 2 Impact test temperature code

Impact test temperature code

The test temperature at which the impact energy (KV2) is not less than 27J

Z a

Y 20

0 0

4.1 Wire size and surface quality

The wire size and surface quality shall comply with the provisions of GB/T 25775.

4.2 T-joint fillet weld

4.2.1 Specimen inspection of fillet welds shall be in accordance with GB/T 25774.3, where the unfused length of the weld root shall not exceed the total length of the weld

20%.

4.2.2 The weld crown and the difference between the lengths of the two weld legs shall comply with the requirements of Table 5.

Table 5 Weld crown and the difference between the two legs are in millimeters

Welded foot size weld crown degree difference between two solder legs

< 7.0 <=2.0

>=7.0 <=2.5

<= (0.5 x solder fillet size -0.5)

4.3 Chemical composition

The chemical composition of the wire deposited metal shall comply with the requirements of Table 6.

Table 6 Chemical composition of deposited metal

Chemical formation

Sub-classification

Chemical composition (mass fraction) a, b

C Mn Si PS Ni Cr Mo V

N2 0.15 1.00~2.00 0.40 0.030 0.030 0.50~1.50 0.20 0.20 0.05

N5 0.12 1.75 0.80 0.030 0.030 1.75~2.75 - - -

N51 0.15 1.00~1.75 0.80 0.030 0.030 2.00~2.75 - - -

N7 0.12 1.75 0.80 0.030 0.030 2.75~3.75 - - -

3M2 0.12 1.25~2.00 0.80 0.030 0.030 - - 0.25~0.55 -

3M3 0.12 1.00~1.75 0.80 0.030 0.030 - - 0.40~0.65 -

4M2 0.15 1.65~2.25 0.80 0.030 0.030 - - 0.25~0.55 -

Table 6 (continued)

Chemical formation

Sub-classification

Chemical composition (mass fraction) a, b

C Mn Si PS Ni Cr Mo V

N1M2 0.15 1.00~2.00 0.80 0.030 0.030 0.40~1.00 0.20 0.50 0.05

N2M1 0.15 2.25 0.80 0.030 0.030 0.40~1.50 0.20 0.35 0.05

N2M2 0.15 2.25 0.80 0.030 0.030 0.40~1.50 0.20 0.20~0.65 0.05

N3M1 0.15 0.50~1.75 0.80 0.030 0.030 1.00~2.00 0.15 0.35 0.05

N3M11 0.15 1.00 0.80 0.030 0.030 1.00~2.00 0.15 0.35 0.05

N3M2 0.15 0.75~2.25 0.80 0.030 0.030 1.25~2.60 0.15 0.25~0.65 0.05

N3M21 0.15 1.50~2.75 0.80 0.030 0.030 0.75~2.00 0.20 0.50 0.05

N4M1 0.12 2.25 0.80 0.030 0.030 1.75~2.75 0.20 0.35 0.05

N4M2 0.15 2.25 0.80 0.030 0.030 1.75~2.75 0.20 0.20~0.65 0.05

N4M21 0.12 1.25~2.25 0.80 0.030 0.030 1.75~2.75 0.20 0.50 -

N5M2 0.07 0.50~1.50 0.60 0.015 0.015 1.30~3.75 0.20 0.50 0.05

N3C1M2 0.10~0.25 0.60~1.60 0.80 0.030 0.030 0.75~2.00 0.20~0.70 0.15~0.55 0.05

N4C1M2 0.15 1.20~2.25 0.80 0.030 0.030 1.75~2.60 0.20~0.60 0.20~0.65 0.03

N4C2M2 0.15 2.25 0.80 0.030 0.030 1.75~2.75 0.60~1.00 0.20~0.65 0.05

N6C1M4 0.12 2.25 0.80 0.030 0.030 2.50~3.50 1.00 0.40~1.00 0.05

GX - >=1.75c >=0.80c 0.030 0.030 >=0.50c >=0.30c >=0.20c >=0.10c

Note. The single values in the table are the maximum values.

a Chemical analysis should be performed according to the elements specified in the table. If other elements are found during the analysis, the total amount of these elements (except iron) should not exceed

0.50%;

b For self-shielded welding wire, Al<=1.8%;

c At least one element meets the requirements, and other chemical composition requirements shall be agreed between the supplier and the buyer.

4.4 Mechanical properties

4.4.1 Tensile test

The tensile test results of the deposited metal shall comply with the requirements of Table 1.

4.4.2 Impact test

4.4.2.1 Charpy V-notch impact test temperature The impact absorption energy (KV2) of five impact specimens was determined as specified in Table 2. In calculation

When averaging the five shock absorption energies (KV2), one maximum value and one minimum value should be removed. Two of the remaining three values should not

Less than 27J, the other may be less than 27J, but should not be less than 20J, and the average of the three values should not be less than 27J.

4.4.2.2 If the optional code "U" is attached to the model, the impact requirements shall be measured according to the temperature specified in Table 2.

Receive energy (KV2). One of the three values can be less than 47J, but should not be less than 32J, and the average of the three values should not be less than 47J.

4.5 Weld ray flaw detection

Weld ray flaw detection shall comply with the Class II regulations of GB/T 3323.

4.6 deposited metal diffusion hydrogen content

According to the negotiation between the supplier and the buyer, if the diffusion hydrogen code is added after the wire type, it should meet the requirements of Table 7.

Table 7 Diffusion hydrogen content of deposited metal

Diffusion hydrogen code

Diffusion hydrogen content

mL/100g

H5 <=5

H10 <=10

H15 <=15

5.1 Wire size and surface quality

5.1.1 Size

The wire diameter is inspected with a measuring tool with an accuracy of 0.01 mm, measured at the same position perpendicular to each other, and the measuring portion is not less than two.

5.1.2 Surface quality

The surface quality of the welding wire shall be visually inspected for any part of the welding wire according to the provisions of GB/T 25775.

5.2 T-joint fillet weld test

5.2.1 Test base metal

The test plate is made of unalloyed steel having a carbon content of not more than 0.30%.

5.2.2 Preparation of test pieces

The test piece preparation of the T-joint fillet weld test was carried out in accordance with GB/T 25774.3. Welding parameters and wire diameter for testing by manufacturer

recommend. For welding wire with welding position code "0", fillet weld test should be carried out at the position of PB; for welding position code "1"

For the welding wire, the fillet weld test shall be carried out at the position of PE and PF (or PG).

5.3 Chemical analysis

5.3.1 Chemical analysis of deposited metal samples shall be prepared in accordance with the provisions of GB/T 25777, or on the tensile test bars of mechanical properties or after breaking.

Made. When the arbitration test is conducted, it shall be carried out in accordance with the provisions of GB/T 25777.

5.3.2 Chemical composition analysis may be carried out by any suitable analytical method. In the arbitration test, the analysis method is confirmed by both the supplier and the buyer.

5.4 Mechanical properties test

5.4.1 Test base metal

The base material for the test of mechanical properties of deposited metal shall be a steel plate equivalent to the chemical composition of the deposited metal. If other base metals are used, they should be

The test layer is used to weld the separation layer on the groove surface and the surface of the pad, and the thickness thereof is not less than 3 mm after processing.

5.4.2 Preparation of test pieces

5.4.2.1 The mechanical properties of deposited metal are prepared according to GB/T 25774.1, using test piece type 1.3, the test plate width is not less than

125mm, gas shielded welding wire is Phi1.2mm, self-shielded welding wire is Phi2.4mm, or other specifications are agreed by the supplier and the buyer.

wire. Welding parameters are recommended by the manufacturer. The welding heat input, number of passes and number of layers prepared for the test piece shall be as specified in Table 8.

5.4.2.2 After the positional welding of the test plate, the temperature of the test plate shall not be lower than 100 °C during the welding, and the temperature between the tracks shall be maintained at 150 °C +/- 15 °C during the welding process.

The preheating temperature and the interpass temperature of the chemical component classified as "GX" are agreed by the supplier and the buyer. When the test plate temperature exceeds, it should be cooled naturally. according to

GB/T 18591 uses a surface thermometer, thermometer or thermocouple to measure the preheating temperature and the interpass temperature.

5.4.2.3 When the test piece requires post-weld heat treatment, it shall be carried out before the tensile test specimen and the impact test specimen are processed. When the test piece is placed in the furnace, the temperature of the furnace shall not be allowed.

Above 315 ° C, from 315 ° C, heated to 620 ° C +/- 15 ° C at a rate of not more than 280 ° C/h, heat preservation 60min ~ 75min. achieve

After the holding time, it is cooled with the furnace at a rate of not more than 195 ° C/h. After the temperature is lower than 315 ° C, it is allowed to be taken out from the furnace and naturally cooled to room temperature. and also

Other heat treatment specifications may be adopted in accordance with the agreement between the supplier and the buyer.

Table 8 Recommended welding heat input, number of rows and layers

Wire diameter

Mm

Average heat input

kJ/mm

Number of tracks per layer

The first layer of the first layer a

Number of layers

<=0.8, 0.9 0.8~1.4 1 or 2 2 or 3 6~9

1.0, 1.2 1.0~2.0 1 or 2 2 or 3 6~9

1.4, 1.6 1.0~2.2 1 or 2 2 or 3 5~8

2.0 1.4~2.6 1 or 2 2 or 3 5~8

2.4 1.6~2.6 1 or 2 2 or 3 4~8

2.8 2.0~2.8 1 or 2 2 or 3 4~7

3.2 2.2~3.0 1 or 2 2 4~7

a The last layer can be completed by 4 channels.

5.4.3 Tensile test

The size and sampling position of the deposited metal tensile specimen are in accordance with GB/T 25774.1, and the tensile test is carried out according to GB/T 2652.

5.4.4 Impact test

5.4.4.1 The size and sampling position of the impact specimen shall be in accordance with GB/T 25774.1.

5.4.4.2 At least one shape of the V-notch of the sample shall be measured in each set of impact specimens, and the measurement shall be at least 50 times larger than the projection.

Perform on a meter or metallographic microscope.

5.4.4.3 V-notch impact test shall be carried out in accordance with GB/T 2650.

5.5 Radiographic test

5.5.1 Weld ray flaw detection test shall be carried out before the interception of the mechanical specimen. The bolster shall be removed before the ray flaw detection.

5.5.2 Weld flaw detection test shall be carried out according to GB/T 3323.

5.5.3 When assessing the weld ray flaw detection film, 25mm at both ends of the test piece shall be disregarded.

5.6 Deposited metal diffusion hydrogen test

The diffusion hydrogen content of the deposited metal is determined according to GB/T 3965. See Appendix G for instructions on diffusible hydrogen.