October 15-17, 2024 at Orange County Convention Center in Orlando, Florida
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Expo Hours

Tuesday Oct 15 9 AM — 5 PM
Wednesday Oct 16 9 AM — 5 PM
Thursday Oct 17 9 AM — 4 PM

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Orange County Convention Center

9800 International Drive
Orlando, Florida 32819

About the Expo

North America's largest metal forming, fabricating, welding and finishing event heads to Orange County Convention Center in October 2024. FABTECH provides a convenient "one stop shop" venue where you can meet with world-class suppliers, see the latest industry products and developments, and find the tools to improve productivity, increase profits and discover new solutions to all of your metal forming, fabricating, welding and finishing needs.

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North America's Largest Metal Forming, Fabricating, Welding and Finishing Event

From the Blog

Understand the Building Blocks for a Quality Welding Program

By Jennifer Dallos on on
A methodical evaluation of the job requirements and welder skills is presented to help new welding engineers develop sustainable programs. By Lee G. Kvidahl, manager, Welding Engineering, Ingalls Shipbuilding, Pascagoula, Miss., and an AWS past president. Reprinted with permission: The Welding Journal A welding program that demonstrates consistent quality performance begins with very basic tools. An understanding of the requirements to produce an acceptable product is communicated, in writing, to the welder who has previously demonstrated sufficient skill and ability by producing workmanship samples tested as required by the customer’s specification. From these building blocks, a program that consistently produces quality welded products can succeed in the modern world economy. The Welding Engineer’s Job A major responsibility for most welding engineers is to develop and create the welding procedure specifications (WPSs). These written instructions provide the technical direction for a welding operation. The WPS is typically based upon objective qualification test data and contains the process essential elements to provide the welder or welding operator the technical information required to complete a weld.
AWS Fig 1

Fig. 1 — The AWS B2.1 specification is a valuable reference.

There are no industry standards for the format or content of a WPS. There is a wide variety of standards and codes (Fig. 1) that suggest a format to be used, but the format is not the most important feature of a WPS. The technical content is the most critical component. Working with the Standards There are many industry standards and codes that do define the information to be provided in each WPS. In many cases, these standards and codes provide very similar directions but not necessarily identical directions. For this reason, it is imperative that each welding engineer research the specific requirements for each of the standards or codes invoked by the customer receiving the welded product. This cannot be stressed enough — the WPS must incorporate all of the information defined by the applicable contractual fabrication standard and not have been based upon an assumption that one WPS may be adequate for multiple standards. Essential Elements of the WPS The core of any WPS is the essential elements. Commonly, a fabrication standard will define what comprises the WPS essential elements and what information is mandatory for inclusion in the procedure. The elements themselves may change based upon the process definition, such as additional elements are required for an automatic process than a manual welding process. Based upon the product being welded and the fabrication standard, the number and specifics of what WPS information is defined as essential will determine the content of the welding procedure. Following are some of the more common essential elements contained in welding procedures.
  • Process — Every WPS requires the type of welding process and additionally whether it is to be used semiautomatically, automatically, or in conjunction with some type of machine.
  • Base Material — Each specification may require this information to be reported in a different manner. Many standards group the potential base materials into families based upon chemistry or mechanical properties. A WPS may simply reference the correct family of materials, as defined by the fabrication standard, or may need to include the applicable material specification and more specific material designations.
  • Base Material Thickness — A WPS may be restricted to a material thickness range. Normally, this is based upon the material thickness used for qualification testing, i.e., the procedure qualification record (PQR).
  • Filler Material — Similar to the base materials, many of the filler materials are grouped together based upon chemistry. While this may simplify a requirement, it is important that the WPS specify the type of filler material to be used for the intended application. For example, it is common for all of the austenitic stainless steel filler materials to be placed into a single group, but the WPS must direct the welder to use the correct alloy for the specific type of base material and the service condition the welded component will experience.
  • Joint Design — The WPS may be restricted to a family or families of joint designs. If the supporting PQR utilized a partial penetration joint design, most likely the WPS may not be applicable for applications requiring a complete-joint-penetration weld. In the case of fully automatic welding procedures, rather than a family of joint designs, the WPS may require a very specific machined weld preparation.
  • Electrical Characteristics — For arc welding procedures, amperage, voltage, and polarity are almost universally required as essential elements. Some standards may accept a wire feed speed range to replace the amperage range in the WPS.
  • Gases — If a gas is used for the welding process, a definition of the type and potential mixes of gases, the minimum flow rate, and whether the procedure requires just a shielding gas in the immediate zone of the arc or if additional shielding gas is required for internal purging or as a trailing shield will be required. It is also common for the WPS to provide direction as to the minimum size of the shielding gas cup to be used.
  • Heating Requirements — Certain materials require a minimum preheat or maximum interpass temperature to be incorporated into the welding operation. The WPS will contain this information as well as any postwelding heating operations such as a low-temperature soaking heat or a full-bore stress relief.
  • Procedural Requirements — Other procedural elements may be required to complete the WPS. Factors such as travel speed, torch orientation, preweld cleanliness, and other attributes may be required by the specifications or codes being employed for the specific job. It is mandatory that the author of the WPS review the specification requirements thoroughly to ensure that the necessary information is contained in the WPS.
Qualifying the WPS Most specifications and codes define the requirements for the qualification of the welding procedure. This process requires the use of the proposed welding procedure (WPS) to make one or more test welds that will be thoroughly examined. The examination may entail nondestructive testing, destructive testing, or in some instances both. This testing is documented in the procedure qualification record (PQR) and provides the objective quality evidence that the welding procedure will produce an acceptable weld when tested for soundness and mechanical properties. Using Prequalified WPSs Not all fabrication standards require a WPS to be qualified prior to being written and implemented. These standards have provisions for prequalified welding procedures. The prequalified procedures are typically used for common welding processes to be used to join common materials in less critical applications. The reason that the procedures are considered prequalified is that there is a large body of knowledge and considerable history of use demonstrating that the prequalified procedure provides the directions required to make acceptable welds without having to do additional testing. When the WPS must be qualified, the first step is to carefully and fully review the procedure qualification requirements as stated in the applicable fabrication document. As with welding procedures, the requirements between different standards may also be different. It can be costly in both time and money, as well as very frustrating, if a test is not performed during the qualification process due to overlooking a requirement and a second test plate or pipe must be welded to provide the necessary test specimens. The Six Qualifying Steps There are typically six steps to qualify a welding procedure. First, understand the requirements from the applicable specification. Second, weld the necessary number of test plates or pipes using the proposed WPS. Depending upon the product application or specification requirements, more than one test piece may be required to be welded. Third, perform all required nondestructive testing. Fourth, perform all required destructive testing. Fifth, document the welding and testing results in the welding procedure qualification test record. Sixth, if required, submit the documentation to the customer for approval. The required nondestructive testing may include visual inspection, which will be needed for all qualification welding, hardness testing, liquid penetrant inspection, magnetic particle inspection, radiography, and in some cases ultrasonic inspection. Rarely are all of these inspection methods required, but in many standards, some combination of these will be necessary. The acceptance criteria will be defined in the applicable standard. Destructive Testing Methods Destructive testing can include fillet weld break test, tensile testing, bend testing, and toughness testing. As with the nondestructive testing, rarely are all of these test methods required, but the applicable standard will define the requirements. The standard will also define the acceptance criteria and the appropriate test conditions for performing these tests. Minimizing Qualification Tests A key part of reviewing the specification requirements is to ensure that the testing encompasses a broad enough range of parameters that additional qualification test work will not be needed in the near future. Most specifications have a range of tolerances on each of the essential elements that permit some variations from the qualification test values so that a WPS may be altered without requiring another PQR test regimen. For example, many standards allow the qualified base material thickness to range from one-half the thickness of the test material to twice the thickness of the test material. If there are several applications that may utilize the same WPS, it is prudent, if possible, to use a material thickness that may include all of the thicknesses required by only performing a single PQR. Each standard has different requirements for changes in the WPS that are allowed without having an additional qualification requirement. The standard should be very carefully reviewed to understand these allowable changes to determine the planned qualification process to ultimately minimize the number of qualification tests being performed while the full range of the WPS stays within the confines of the specification tolerances. Welder Certification In addition to welding procedure development and qualification, virtually all standards define requirements for welder certification. Many of the standards have similar requirements but, as expected, they will not be identical. Fortunately, many of the standards have requirements that are very similar, so that the customer of the welded product may accept the welder certification testing from an alternate specification. Rarely are welder certifications transferable between different employers without an additional performance test. While this process may permit a national certification program to be considered for welder certification, the reality is that each employer will most likely require a welding test to be included in the hiring process. By having a national certification, the welder has demonstrated the skill necessary to make quality welds and this should simplify the welder certification process. Typically, pipe and structural certifications have different requirements. Based upon the application, the standards should be reviewed to determine whether a single certification test may be applied to all of the required production welds. Many standards define a pipe with a diameter of 24 in. or greater to be a plate, so this type of information may be of consideration for the welder certification process. Conclusion Many standards define the welder certification application by process and filler material. Depending upon the applicable standard, one filler material grouping may also certify the use of additional filler material groupings. By understanding this allowance, a company may be able to certify their personnel for multiple applications by using a single welder certification test package. A detailed understanding of the applicable welder certification testing process will provide the path to have a fully certified welder with a minimum of test welds being made. Summarizing, the basic building block of a quality welding program is the conformance to the applicable specification requirements for welding procedures, their qualification testing to demonstrate the acceptance of the procedures and the talent of the welder as demonstrated by the certification process. By performing all of these developmental steps, a welding program is on the road to success and will provide welded products that meet the customer’s requirements.

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