Under-flux welding wire standard

Under-fluxed wire standard for welding non-alloy and alloy steel (DIN 8557 Part 1 April 1981).

This standard is developed by the German Welding Association. Roll Filled Welding Wire For Under-fluxed Welding For welding non-alloy and alloy steel and including the weld obtained from the welding wire combined with the flux

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  1. Types and symbols of welding wires

Welding wires are classified according to their chemical composition.

S means the wire under the flux. The number at the end of the letter S indicates the manganese content.

For example, S2 average manganese content 1% and S4 average manganese content 2%.

For the element code after the number have the following meanings

Si means the silicon alloy has increased more than normal.

Mo is about 0.5% of the molybdenum alloy.

Ni is a nickel alloy wire. The average quantity is expressed as a percentage at the end of Ni.


Symbol for Wire Electrode 1%Mn and increased silicon content (S2Si)

for under-flux welding

Wire Electrode DIN 8557-S2Si

  1. Symbol of the weld from the welding wire combined with the flux.

symbol of weld It will consist of the following components:

1) The word Weld Metal (welded meat)

2) DIN number

3) Under-flux welding process code (Up)

4) Yield Point code of weld

5) The code number shows the impact test value of the weld.

6) Welding wire symbol

7) Alphabetical code for production methods and flux mixtures according to DIN 32522 , April 1981.

8) Flux quality class number code according to DIN 32522 April 1981

9) Silicon and Manganese Elemental Gain and Loss Number Code

Examples of symbols

Symbol for welds obtained from flux-contained welding wire for under-fluxed welding (Up). Minimum Yield Point 420 N/mm² (Y 42). Minimum Impact Test Value 28 g at -30%. and 47 μC at -20ºC (43). S4 welding wire and FMS1 type flux were used, with 0.2% silicon gain and 0.2% manganese loss (64).

Weld Metal DIN 8557-Up Y42 43 S4 FMS1 64

2.1 Yield Point code of weld

2.2 Code number showing the impact test value of the weld

2.3 Receiving and Loss Number of Silicon and Manganese Element Codes

3.10 Flux for Submerged Arc Welding DIN 32522-April 1981 (Flux for Submerged Arc Welding)

This standard was compiled by the German Welding Association. This flux is used for welding non-alloy steel, low alloy steel, high alloy steel, nickel and nickel alloys with wire electrodes and strip electrodes.

  1. Types and symbols of flux

Flux for welding under granular flux obtained from the use of minerals to produce which has many production methods Flux influences the chemical composition of the weld. Flux classification shall be classified according to the production process (Section 1.2), by the major chemical ingredients (Section 1.3) and by the quality class of flux (Section 1.4).

1.1 Flux Symbol

The flux symbol consists of the following parts:

1) Flux word

2) DIN number

3) Symbol indicating the flux production process (Section 1.2)

4) Alphabetical symbols for the main chemical ingredients (Section 1.3)

5) Numeric symbols for flux quality classes (Section 1.4).

6) Metallurgical Behavior Code (Section 1.5)

7) Symbol for welding current (Section 1.6).

8) Symbol for the amount of welding current used (Section 1.7)

9) Other qualification symbols (Section 1.8)

1.2 Symbols showing the production process

Characters showing the flux production process are:

F = Fused Flux

B = Bonded Flux

M – Mixed Flux

Fused Flux is a flux produced by melting a mixture of fluxes, cooling them and then grinding them into pellets.

Bonded Flux is a flux in which ingredients are dried. and then taken to separate the sizes (without being forged)

Mixed Flux is a flux obtained by mixing two or more fluxes. by the manufacturer

1.3 Alphabetical symbols for the main chemical ingredients

Fluxes are classified according to their main chemical composition. and the symbol is determined according to the main ingredient of the element

1.4 class quality of flux

Quality Class 1

Flux for welds and filets Non-alloy and low-alloy steels include general structural steels, fine-grained steels, high-temperature steels. The weld will receive or lose carbon, silicon and manganese only, the impurity element will not cause any negative effects. weld properties

Quality Class 2

Flux for welds and filets Non-alloy and low-alloy steels include general-building steels, fine-grained steels, low-temperature steels and high-temperature steels. The weld will receive or lose only carbon, silicon and manganese to improve the properties of the weld as well.

Quality Class 3

Flux mixed with low alloy steel weld metal. that provides hardness, wear resistance The weld will get more mixed elements as C , Cr , Mo or other elements.

Quality Class 4

Flux for high temperature martensitic steel welds which contains more than 5% chromium by weight, and the flux can also be used for the aforementioned weld metals.

Quality Class 5

Chromium-containing flux which prevents the burning of chromium For connecting and reinforcing masking Stainless steel, heat resistant chromium steel and chrome-nickel steel

Quality Class 6

Flux without chromium as the main ingredient For joining and reinforcing stainless steel, chromium heat resistant steel and chrome-nickel steel.

Quality Class 7

Flux for connecting and reinforcing masking Nickel and Nickel Mixtures

1.5 Details of metallurgical behavior

Metallurgical behavior of gain and loss of alloying elements formed by flux As a result, welds are qualified to The metallurgical properties are different from the properties of the welding wire.

1.6 Symbols for Power

symbol for welding current The international ones are as follows:

DC = direct current

AC = alternating current

Flux suitable for AC current is also good for DC current.

1.7 Symbol for quantity of welding current

The maximum welding current is determined by the maximum current divided by 100.

1.8 Font symbols for other properties

S flux for high speed welding

The flux designed to be welded at high speed is not less than 1.5 m/min. The velocity can be determined by welding with a 4 mm wire, DC current, anode wire.

K flux for filet welding

This flux is designed for easy removal of slag. Beautiful welds when welding flat and level filets.

M flux for multi-wire welding

A special type of flux used for welding with multiple electrodes. lines at the same time

B flux for reinforced welding

Special fluxes are designed to be suitable for welding reinforced strips (Strip Electrodes).

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