This article provides information about A number in welding procedure specification based on requirement of ASME Code Section IX.
A number gives a similar chemical composition in a “as weld”condition. The A number is essential variablein most of welding process in ASME Code Section IX. The Table QW-442 in ASMECode Section IX provides the list of A number. Please note the A number inWPS does not refer to the filler wire or electrodechemical composition; it refers to the deposited weld metal chemical composition.The filler metal and deposited weld metal have different chemical compositions.
How Do You Determine the A number in Welding ProcedureSpecification?
It can be obtained from procedure qualification coupon. The smallpiece of welding can be removed and chemical analysis test to be performed. Thenthe obtained chemical composition must be compared against the table QW-422 andA number to be selected.
Alternatively if your welding process is one of SMAW, GTAW,LBW and PAW processes you may use the filler metal specification or test reportof filler metal manufacturer.
F-Numbers of filler metals can be found in ASME Section IX’s Number Table QW-432 an extract is shown as following: F - Numbers. Electrodes/Welding Rods: F - No. 1 through F - No. 6: Steel and Steel Alloys: F - No. 21 through F - No. 25: Aluminum and aluminum - base alloys: F - No. 31 through F - No.
Filler metals not listed in Table B.1, but assigned an F-Number by ASME Section IX, are considered as listed filler metals. Is a base metal grouping & classification within the P-No. For impact test requirements. Is a filler metal (electrodes & welding rods) grouping for qualification, and is based essentially on their usability characteristics which determine the ability of welders to make satisfactory welds with a given filler metals. Filler metal suggestions “match” the base metal properties; that is, the yield and tensile strength are expected to meet or exceed the minimum specified properties of the steel. Matching filler metal is.
![Metal Metal](/uploads/1/1/7/9/117906464/976407444.png)
Similarly you can do same assessment for GMAW and EGWprocesses but the shielding gas should be as the same of welding procedure specification.
Again, similarly you can do the same for SAW but the fluxshould be as the same of welding procedure specification.
As mentioned in above, the A number like P number and F number is an essential variablein most welding processes. It means if you have a WPS and you need to use thatin other job with different A number (it means you are using different fillermetal) then you need to re-qualify your WPS because it is essential variable.The A number 1 and 2 are exceptions. You can consider it as nonessentialvariables.
The ASME Section IX Training Course is 2 days video training course and available online and the student that successfully pass the exam, receive I4I academy certificate with 16 hours training credit.
Related Articles:
Group Number, Supplementary Essential Variable, Welding Performance Qualification, Pressure Vessel Inspection
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Have your say about what you just read! Leave me a comment in the box below.A filler metal is a metal added in the making of a joint through welding, brazing, or soldering.
Soldering[edit]
Soldering and brazing processes rely on a filler metal added to the joint to form the junction between the base metal parts. Soft soldering uses a filler that melts at a lower temperature than the workpiece, often a lead-tin solder alloy. Brazing and hard soldering use a higher temperature filler that melts at a temperature which may approach that of the base metal, and which may form a eutectic alloy with the base metal.
Filler alloys have a lower melting point than the base metal, so that the joint may be made by bringing the whole assembly up to temperature without everything melting as one. Complex joints, typically for jewellery or live steam boilermaking may be made in stages, with filler metals of progressively lower melting points used in turn. Early joints are thus not destroyed by heating to the later temperatures.
Welding[edit]
Welding processes work around the melting point of the base metal and require the base metal itself to begin melting. They usually require more precise distribution of heat from a small torch, as melting the entire workpiece is avoided by controlling the distribution of heat over space, rather than limiting the maximum heat. If filler is used, it is of a similar alloy and melting point to the base metal.
Not all welding processes require filler metal. Autogenous welding processes only require part of the existing base metal to be melted and this is sufficient, provided that the joint is already mechanically close-fitting before welding. Forge- or hammer welding uses hammering to close up the hot joint and also to locally increase its heat.
Filler Metal F Nose
Many gas welding processes, such as lead burning, are typically autogenous and a separate wire filler rod of the same metal is only added if there is a gap to fill. Some metals, such as lead or Birmabright aluminium alloy, use offcut strips of the same metal as filler. Steels are usually welded with a filler alloy made specially for the purpose. To prevent rusting in storage, these wires are often lightly copper plated.
With electric arc welding, a major use for the filler rod is as a consumable electrode that also generates heat in the workpiece. An electrical discharge from this electrode provides heat that melts both the electrode and heats the base metal.
TIG welding is an electric welding process that uses a non-consumed tungsten electrode to provide heat, with the filler rod added manually. This is more like gas welding as a process, but with a different heat source.
Hard-facing[edit]
A specialist use for filler metal is where a deliberately different metal is to be deposited. This is often done for hard-facing excavating tools or digger bucket teeth. A hard, but more expensive and sometimes brittle, facing alloy is deposited onto the wear surfaces of mild steel tools.
Four types of filler metals exist—covered electrodes, bare electrode wire or rod, tubular electrode wire, and welding fluxes. Sometimes non-consumable electrodes are included as well, but since these metals are not consumed by the welding process, they are normally excluded.
Usage[edit]
Covered electrodes[edit]
Covered electrodes are used extensively in shielded metal arc welding and are a major factor in that method's popularity.
Bare electrode wires[edit]
Bare electrode wires are used in gas metal arc welding and bare electrode rods are used in gas tungsten arc welding.
Tubular electrode wires[edit]
Tubular electrode wire is used in flux-cored arc welding.
Welding fluxes[edit]
Welding fluxes are used in submerged arc welding.
See also[edit]
- Autogenous welding, welding processes without filler
References[edit]
- Cary, Howard B. and Scott C. Helzer (2005). Modern Welding Technology. Upper Saddle River, New Jersey: Pearson Education. ISBN0-13-599290-7.
Filler Metal F Notes
Filler Metal F-no 6
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