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Inspection Trends - January 2011 - Winter

production as was used to qualify the welding procedure. The name of the manufacturer, model number, and the pulsing program are also important information that should be recorded on the PQR by the test witness and needs to be listed on the WPS used for production. Travel speed is listed in units of inches per minute or millimeters per second. It is the distance divided by the time it takes to weld from point A to point B along the length of the joint. Whether the welder utilizes a stringer bead or a weave bead can influence the mechanical properties of the completed weld. In general, when welding carbon steels, the use of a weave bead technique results in higher heat input, slower cooling rates, coarse grains, higher ductility, slightly lower tensile and yield strengths, and lower toughness in comparison to a weld made using stringer beads. Provided we restrict the conversation to low and mild carbon steels, both weave and stringer beads will meet the minimum ultimate tensile strength and yield strength requirements of the applicable welding standard if a matching filler metal is used. However, if the base metals being welded are aluminum alloys, quenched and tempered steels, austenitic stainless steels, etc., changes in heat input can have a dramatic influence on the mechanical properties. The interrelationship between arc voltage, WFS, and amperage can make it difficult to present the information to the welder in a meaningful way. A graphic presentation is easier for the welder to use than simply listing the voltage, WFS, and amperage as ranges without correlation. The WPS that follows illustrates one way to present the welding parameters for a semiautomatic welding process such as FCAW. 34 Inspection Trends / January 2011 Welding Procedure Specification WPS: GTA/FCA-P1F6 WPS: GTA/FCA-P1F6 Rev.: O Date: 28-Nov-10 Supporting PQR: GF-P1F6-A Rev.: — Date: 19-Oct-10 Process: GTAW MA X SA — ME — AU — Process: FCAW MA — SA X ME — AU — Base Metal Base Metal: Low-carbon, medium-carbon, Low-carbon, medium-carbon, Alloy/Grade: and high-strength low-alloy and high-strength low-alloy steels. Refer to Annex A-1. steels. P No.: 1 1 Product Form: Shapes, plate, pipe, & fittings Welded to Shapes, plate, pipe, & fittings Thickness: 1⁄16 through 2 in. 1⁄16 through 2 in. Diameter: All diameters All diameters Group No.: 1 1 Joint Details Fillet welds, partial joint penetration groove welds, and complete joint penetration groove welds as depicted in Annex B-2 Filler Metal Process: GTAW FCAW Weld Layer: Root and 2nd layer Intermediate and cover Specification: ASME A5.18 ASME A5.20 Classification: E70S-2 E71T-1MJH4 (ESAB Dual Shield II 70T-12H4) F Number: 6 6 Diameter: 1⁄8 in. 0.045 in. Product Form: Rod Spooled wire A No.: 1 1 Maximum Deposited Thickness: 1⁄2 in. 11⁄2 in. Consumable Insert: None None Classification: NA NA Supplementary Flux: None None Fig. 4 — A sample WPS that was qualified by testing. (The WPS continues on pages 35 and 36.)


Inspection Trends - January 2011 - Winter
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