GB/T 17493-2018Tubular cored electrodes for creep-resisting steels (English PDF)

3.1 Model division

The wire type is drawn according to the mechanical properties of the deposited metal, the use characteristics, the welding position, the type of shielding gas and the chemical composition of the deposited metal.

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 six 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. indicates the use of the feature code, see Table 2;

4) Part IV. indicates the welding position code, see Table 3;

5) Part 5. indicates the type of protective gas type, the code of the protective gas is in accordance with ISO 14175, see Appendix D;

6) Section 6. 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.

Diffusion hydrogen code "HX", where "X" can be the number 15, 10 or 5, respectively representing the maximum amount of diffusible hydrogen per 100 g of deposited metal Value (mL), see 4.6.

The wire type examples in this standard are as follows:

Example 1:

T 55 T5-0 M21-1CM H5 Optional additional code means that the diffused hydrogen content of the deposited metal is not more than 5mL/100g Indicates the chemical composition of deposited metal Indicates the type of protective gas, "M21" means the gas composition is (15%) < CO2 <=25%) Ar Indicates the welding position, "0" indicates the flat welding and the fillet welding position Indicates the use characteristics, "T5" indicates that the core type is calcium oxide-fluoride, using DC reverse or DC positive connection, coarse drop transition, etc.

Indicates the tensile strength of the deposited metal, and "55" indicates a minimum of 550 MPa. Flux cored wire Example 2:

T 62 T15-1 M13-2C1M Indicates the chemical composition of deposited metal Indicates the type of shielding gas, "M13" indicates that the gas composition is (0.5% <= O2 <= 3%) Ar Indicates the welding position, "1" indicates the full position Indicates the use characteristics, "T15" indicates that the core type is metal powder type, using DC Reverse connection, fine droplet ejection transition, etc.

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

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 4.

4.3 Chemical composition

The chemical composition of the deposited metal of the wire shall comply with Table 5.

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 Cu <= 0.50%. c Nb. 0.02%~0.10%, N. 0.02%~0.07%, Cu<=0.25%, Al<=0.04%, (Mn Ni)<=1.40%. d Nb. 0.01% to 0.08%, N. 0.02% to 0.07%, Cu <= 0.25%, and Al <= 0.04%.

The categories not listed in the e table can be represented by similar classifications, prefixed with the letter "G". The chemical composition range is not specified, and it is not possible between the two classifications. replace.

4.4 Mechanical properties

The tensile test results of the deposited metal shall comply with the requirements of Table 6.

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.

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. 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, For welding, Phi1.2mm welding wire is used, or other specifications are agreed by the supplier and the buyer. Welding parameters are recommended by the manufacturer. Test piece preparation The welding heat input, number of passes and number of layers shall be as specified in Table 8.

5.4.2.2 After the positioning of the test plate, the temperature of the test plate shall reach the specified preheating temperature during the welding, and the temperature between the channels shall be maintained during the welding process. When the test plate temperature exceeds, it should be cooled naturally. Preheating temperature and surface temperature measurement according to GB/T 18591 using a surface thermometer, thermometer or thermocouple The temperature between the roads.

5.4.2.3 When the test piece requires post-weld heat treatment, it shall be carried out before the processing of the tensile specimen. The heat treatment conditions shall be as specified in Table 6. The test piece is placed in the furnace When inside, the furnace temperature should not be higher than 315 ° C, from 315 ° C, to a specified temperature at a rate of not more than 280 ° C/h. Reaching the holding time Thereafter, it is cooled with the furnace at a rate of not more than 195 ° C/h, and is allowed to be taken out of the furnace after being lower than 315 ° C, and naturally cooled to room temperature. Also available under It is necessary for both parties to agree to adopt other heat treatment specifications.

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.

5.5 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.