WPS QW-403 Base Metals
ASME Section IX WPS : QW-403 Base Metals Example
ASME Section IX Welding Variables for a WPS : QW-403 Base Metals
QW-403.5 Group Number
This is a Supplementary Essential Variable
This only applies when toughness testing is a requirement
The group number of the P-Number becomes a supplementary essential variable
When applicable It is best that the PQR utilize two group numbers between the two pieces of material. This allows for the WPS to list both of the group numbers in the range it covers.
Example: PQR uses the two materials below, so the WPS covers P-No. 1 Groups 1 & 2
SA-516 Gr 60 = P-No. 1 Group 1
SA-516 Gr 70 = P-No. 1 Group 2
or
SA-106 Gr B = P-No. 1 Group 1
SA-106 Gr C = P-No. 1 Group 2
QW-403.6 Toughness Thickness Limits
This is a Supplementary Essential Variable
This only applies when toughness testing is a requirement
This variable restricts the range of thickness otherwise permitted in Section IX
This may require multiple thin and thicker PQR coupons to cover the desired range of thickness on the WPS
ASME B31.3 now refers to the thickness restrictions listed in QW-403.6 for toughness applications
There are some exceptions listed for the following P-Numbers regarding the thickness limitations
P-No. 8 (Austenitic Stainless Steel)
P-No. 21 thru 26 (Aluminum Alloys)
P-No. 41 thru 49 (Nickel Alloys)
QW-403.8 Base Metal Thickness
Establishes the range of base metal thickness qualified on the WPS based on the PQR coupon when toughness testing does not apply
QW-451 contains a table of thickness ranges permitted on the WPS based on the PQR thickness
QW-403.9 Filler Metal Thickness per Pass
This restricts the use of a weld pass thicker than 1/2 inch in thickness. If the weld pass thickness exceeds 1/2 inch a restriction is placed upon the base metal thickness of only 1.1 times that of the PQR thickness.
QW-403.11 P-Number Qualified
Limitations of what P-Numbers are permitted on the WPS based on the material and P-numbers used on the PQR
A table is provided in paragraph QW-424 where the PQR P-Number is listed with the corresponding range of base metals qualified for the WPS
Essential Variable: Variables for which a change is considered to affect the mechanical properties (other than notch toughness) of the joint. Essential variable changes that fall outside their qualified range requires re-qualification.
Supplementary Essential Variable: Variables for which a change is considered to affect the toughness properties of the joint, heat-affected zone (HAZ), or base material.
Supplementary essential variables become additional essential variables in situations where toughness testing is required. When toughness testing is not required supplementary essential variables are not applicable.
Non-Essential Variable: Variables for which a change is considered to not affect the mechanical properties of the joint. This allows for editorial revisions to procedures within that permitted by Section IX without the need to requalify the procedure. Nonessential variables shall be documented on the procedure.