AWS D1.1_2010-Clarification on Table 4.5 x 4.6 x 4.8

Date 12-06-2015 22:50

Dear Sirs

Table 4.5 - PQR Essential Variable Changes Requiring WPS Requalification for SMAW, SAW, GMAW, FCAW, and GTAW (see 4.8.1)
4.8.1 SMAW, SAW, GMAW, GTAW, and FCAW.- Changes beyond the limitations of PQR essential variables
for the SMAW, SAW, GMAW, GTAW, and FCAW processes shown in Table 4.5 and Table 4.6 (when CVN testing is specified) shall require requalification of the
WPS (see 4.2.1.3).
Table 4.6 - PQR Supplementary Essential Variable Changes for CVN Testing Applications Requiring WPS Requalification for SMAW, SAW, GMAW, FCAW, and GTAW
Table 3.1, Table 4.9, and Unlisted Steels Qualified by PQR (see 4.8.3)
4.8.3 Base-Metal Qualification. WPSs requiring qualification that use base metals listed in Table 3.1 shall
qualify other base metal groups in conformance with Table 4.8. WPSs for base metals not listed in Table 3.1 or
Table 4.9 shall be qualified in conformance with Clause 4. The use of unlisted base metals shall be approved by
the Engineer.
_________________________________
Please advise if my understanding is correct-
PQR qualified with CVN Impact Testing shall not be used for welding Group I Materials( For example ABS Grade A - without CVN Impact Testing)
Table 4.8 Group Material combination range solely applicable when CVN Impact Testing is not required.

To my knowledge all Group II Material- (Higher Strength Material) manufactured with CVN Impact Value ( For example ASTM A131 Grouo II- EH36 with CVN Impact Tested to -40deg C/ DH36 with -20deg C...etc)

How i can benefit from this range as shown below (Table 4.8), when my PQR Qualified with ASTM A131 Group II-EH36( Impact Tested to -40deg C)

Any Group II Steel to Any Group II Steel( PQR Base Metal) x (WPS Base Metal Group Combinations Allowed by PQR) Any Group I Steel to Any Group I Steel
Any Group II Steel to Any Group I Steel
Any Group II Steel to Any Group II Steel

Can i use this PQR to weld Group I & II Base Materials Combination- Butt or Fillet Welds( For example ABS Grade A to ABS Grade EH36)?

Thanks

By 803056

Date 12-06-2015 23:11

Sorry Nalla. I would need the code by my side to answer your questions. I'm teaching in New Orleans this week and I don't have my D1.1 with me. Just to make sure everyone is on the same page, are you using D1.1:2010?

Best regards - Al

By Nalla

Date 12-08-2015 22:26

Yes, Sir
Contract signed in 2012

By 803056

Date 12-08-2015 23:13

So, unless otherwise specified by the project documents, it seems reasonable to use the 2010 edition of D1.1. However, I would do some research to confirm the assumption.

Best regards - Al

By Nalla

Date 12-10-2015 07:22

Dear Sir
I also would like to know about max variation allowed on Preheating and Interpass Temp
AWS D1.1_2010- Table- 4.5 - Preheat Temp and Interpass Temp. - max allowable decrease-15 deg C.

PQR Test Coupong thk - 25.4mm x ASTM A131 Grade EH36.Weld Process- FCAW with Steel Backing Strip x Filler Metal Dia-1.2mm.
CVN Impact Tested to -40 deg C and passed.

As per Table 3.2-Cat B - i did preheat just to remove moisture about 10deg C
So in WPS i can state Preheat Temp. -0deg C to 10deg C or maximum 10deg C for thk range 3mm to 38mm,am i right?

And for Filler Metal max Oscillation ( Weld weave bead width ) is not an essential variable for Manual/ Semi-Auto Weld process.
Normal Industry Practice for FCAW process is 13 x wire dia( 15.6mm) [ But i cannot find supporting evidence ].
Normally 3 x electrode dia limitation apply for GTAW and SMAW process only

However, Client Spec allow only 3 x filler metal dia. So client questioning my WPS/PQR.
"When impact test is required, weaving shall be restricted to a maximum weld deposit width of 3 times the filler metal diameter, not to exceed 10 mm, or less if specified in the welding procedure."

Is there anyway, i can justify PQR Weld bead width?

Thanks

By Nalla

Date 12-10-2015 11:35

Dear Sir
Regarding Max Weld bead width allowabel-
Can i use AWS D1.1_2010-Table 3.7-Prequalified WPS Requirementsf (see 3.7) to justify?

Maximum Single Pass Layer Width - All (for GMAW/ FCAW) F & H (for SAW) - Note e
"Note e - e In the F, H, or OH positions for nontubulars, split layers when the layer width w > 5/8 in [16 mm]. In the vertical position for nontubulars or the flat, horizontal, vertical, and overhead positions for tubulars, split layers when the width w > 1 in [25 mm]."

Thanks

By 803056

Date 12-11-2015 00:22

Hello Nalla;

Prequalified WPS (Clause 3 and the tables) do not address CVN testing. Any WPS requiring CVN must be qualified in accordance with clause 4 part d.

Part of the data collected includes arc voltage, welding current (wire feed speed), and travel speed. Heat input must be calculated using the formula Q=(ExIx60)/V. The permitted range of the parameters is limited by the table in clause 4. Travel speed is a function of technique, specifically the use of stringers (high travel speed) versus weave beads (slow travel speed). The travel speed has more influence on heat input that either voltage or current because both are a function of the electrode diameter. The usable range of voltage and amperage is limited to +/- some practical limit. Travel speed on the other hand can vary by a factor of 2, 3, or 4 depending on the use of a stringer, or a weave twice the diameter o the electrode, three times the electrode, etc.

The calculated value of heat input is what determines (to a great extent) or limits the width of the weave bead. After all, wide weaves translates into high heat input if Voltage and amperage are held constant when compared to a stringer bead.

I cannot quote chapter and verse because I'm on the road and I do not have my copy of D1.1 handy.

Best regards - Al

By Nalla

Date 12-14-2015 14:09

Dear Sir
Noted.
As per Table 4.5 & 4.6- Preheat/Interpass Temp.-Essential and Supplementary Essential Variables.
My understanding essential/supplementary parameters shall be recorded in PQR Test Run Data Sheet.
Amp, Volt, Travel Speed, Current Polarity, Preheat and Interpass Temperature shall be recorded

During PQR Qualifications- Is it mandatory to record Interpass Temperature starting Fill to Capping Passess?
If yes, pls advise where indicated
Sorry, i cannot find anywhere it mentioned in AWS D1.1.

In one of the PQR received Interpass Temp. shows - Fill to Capping - less or equal to 250 deg C !!

Thanks

By 803056

Date 12-14-2015 22:42

Hello Nalla;

I record the test data for every bead deposited. That includes the interpass temperature for each bead and the thickness deposited layer by layer. I want to know the running average cross sectional area of the weld beads. I also calculate the heat input for each weld bead.

The data is digested using Excel Statistical Analysis Tool to give me a break down of the average voltage, amperage, travel speed, etc. The variances for the parameters, it also tells me the maximum interpass temperature, the minimum preheat temperature used, and the average heat input. It provides me with a rational data base on which to develop a meaningful WPS.

Best regards - Al

By welderbrent (*****)

Date 12-15-2015 22:50

EX,

WELCOME TO THE AWS WELDING FORUM!!

First, it would have been better to start your own thread, no worries. Just try to do so from now on.

Second, without know exactly what those materials are, the main items of interest for determining preheat are going to be material thickness, material grade, and job specifications. Not to mention the applicable code.

Thickness, preheat is calculated for the thicker member and the joint is heated to that temperature for 3" in any direction from the weld for the through thickness of the parts.

Grade, carbon equivalency is critical in many applications outside pre-approved materials for a given code and has a formula to figure out that number and choose preheat and interpass from there.

Job specifications can alter what code requirements are at the discretion or preference of the engineer, customer.

Codes can have some variation due to product usage for the arena they are written to provide guidance for. Bridges differ from pipelines which differ from structural, etc.

Some added information would help us to give you good advice.

He Is In Control, Have a Great Day, Brent