NB/T 47018.5-2017Technical delivery conditions of welding materials for pressure equipment - Part 5: Stainless steel strip electrodes and fluxes for overlay welding (English PDF)

3.1 Model of electrode strip

3.1.1 The model of electrode strip shall be divided according to its chemical composition.

3.1.3 The model example of electrode strip is as follows: […]

3.1.2 The model of electrode strip consists of two parts

a) The two letters "EQ" in the first part indicates the electrode strip;

b) The number or a combination of numbers and letters after the letter "EQ" in the section part indicates the chemical composition classification, where "L" means that the carbon content is low. If there are other chemical compositions with special requirements, the chemical compositions are represented by element symbols and placed behind.

3.2 Model of deposited metal

3.2.1 The model of deposited metal is classified according to the chemical composition of the deposited metal after the electrode strip-flux assembly.

3.2.2 The model of deposited metal usually consists of four parts. The letter "F" represents flux; the letter after "F" represents the overlay welding method; the number or the combination of numbers and letters after "F" represents the type code of the chemical composition of the deposited metal, where "L" represents the lower carbon content. If there is a chemical composition with special requirements, the chemical composition is represented by the element symbol and placed after the number; the "-" is followed by the position code of the overlay welding layer.

3.2.3 The model example of deposited metal is as follows:

Indicates the low carbon content of electrode strip Indicates the type codes of chemical composition of electrode strip Indicates the electrode strip from each batch of flux; if sampling from the packaged flux, at least 6 bags shall be sampled from each batch of flux, and a certain amount of flux shall be taken from each bag, with a total amount of no less than 10kg. Mix the extracted flux uniformly; and take out 5kg by quarter method for welding test pieces; and the remaining 5kg for inspection of other items.

6.2 Acceptance

6.2.1 The surface quality inspection results of each batch of electrode strips shall comply with the provisions of 4.2.1.

6.2.2 The size inspection results of each batch of electrode strips shall comply with the provisions of Tables 1 and 2.

6.2.3 The chemical composition inspection results of each batch of electrode strips shall comply with the provisions of Table 3.

6.2.4 The quality inspection results of each batch of flux shall comply with the provisions of 4.3.

6.2.5 The chemical composition of the deposited metal after each batch of electrode strip-flux combination shall comply with the provisions of Table 5.

6.2.6 The bending performance results of the deposited metal after each batch of electrode strip-flux combination shall comply with the provisions of 4.5.

6.2.7 The ferrite content of the deposited metal and the corrosion resistance of the deposited metal after each batch of electrode strip-flux combination shall comply with the provisions of 4.6 and 4.7.

7.1 Inspection content

The quality certificate of overlay welding materials for pressure equipment shall contain the batch numbers of flux, transition layer electrode strip and corrosion-resistant layer electrode strip, and their respective inspection results, as well as the results of inspection after flux, electrode strip and assembly overlay welding.

7.2 Batch number

The batch numbers of flux, transition layer electrode strip and corrosion-resistant layer electrode strip used for pressure equipment shall meet the requirements of the quality certificate in 7.1; when only one of the above three batch numbers is different from that in the quality assurance certificate, it shall be inspected according to the quality assurance system of this organization, and the technical requirements shall be no […]