WELDER QUALIFICATION AND CERTIFICATION
WHAT IS CERTIFICATION?
The term “Certification” as it applies to welders refers to a document that states “I or We certify that” the indicated welder or welding operator has successfully completed a practical test of their abilities to perform a sound weld in accordance with some predetermined standard.
The term Qualification means that a welder or welding operator has met the requirements of a given Standard and is qualified to perform welds to within the scope of the standard.
To become certified the Welder must posses the skills necessary to produce a sound weld that is visually acceptable and meets the testing requirements.
KEY POINT: To get a job or keep a job welders often have to make a weld to show they are capable welders
The Testing Procedure involves the welder making a weld that is then tested by an Inspector, to ensure the weld conforms to a particular Code, Standard, or written Welding Procedure Specification. Testing Methods include Visual inspection, and may involve either destructive or non-destructive testing.
CODE: Rules or laws that may have legal status and are considered mandatory especially when language like shall, Will or Must is used.
STANDARD: A document, sample or thing that describes or shows exactly what the outcome should be.
SPECIFICATION: A detailed description of the parts or variables to be controlled.
An example of Destructive Testing is when the inspector prepares a specimen from the weld and bends the specimen against the weld to determine if it meets the requirements of the Standard.
An example of non destructive testing is when a completed weld joint undergoes an X ray and the inspector reads the X ray film to determine if it meets the requirements of the standard.
In a typical welding Test or Certification, the welder must weld follow a set of written instructions contained in the Welding Procedure Specification (WPS) to produce the Weld Specimen for testing.
A simple test may involve the following steps;
1 Ensure the proper safety equipment and welding supplies.
2 Set the welding parameters on the welding machine.
3 Ensure the appropriate supplies are available.
4 Obtain the appropriate supplies and metal pieces to be welded.
5 Prepare and assemble the joint to be welded.
6 Place the weld in the proper welding position.
7 Follow the indicated procedure to fill the joint with Weld.
8 Prepare or help prepare the specimens to be tested.
The Welding Inspector (Test Supervisor) will guide the preparation of the pieces, assembly, and periodically check progress to ensure conformity to the Standard.
KEY POINT: Your weld coupons will be examined and tested to make sure they are good welds
There is no one universal test to Certify Welders to all welding conditions. Welders may have to Cerify for each process (stick, mig, tig etc) used, and for each group of steels (mild steel, stainless, aluminum). In addition some tests cover all positions of welding while some restrict positions.
When a welder becomes certified through a testing facility they usually receive a document called a Welder Test Report that details the welder’s qualification range.
Delta certified Welders also receive a test report in the form of an actual certificate with all the variables listed.
KEY POINT: You are only certified to do what you tested for; ask questions about your qualification.
WHO CONDUCTS CERTIFICATION?
A Certification may be given by a testing facility’s Inspector or authorized personnel or by a companies representative such as quality control personnel, supervisors, or engineers as long as they are in accordance with the Code or Standards requirements for Qualified Testing personnel.
Some companies require certification to be specific to their needs and they maintain the records of certification. A welder may have many certifications covering a wide range of variables.
KEY POINT: You may not see or receive any documentation if a company pays for testing
THE AWS CERTIFIED WELDER PROGRAM
The AWS (American Welding Society) has developed a program for certifying Welders to National Standards that is recognized by many Industries and allows certifications to be transferable or accepted by Companies without further testing. A database of currently Certified Welders is maintained by the AWS for verification of a welders certification status.
Delta School Of Trades is an accredited testing facility, listed as Delta Welding And Engineering on the AWS list of authorized testing Facilities.
SEE OUR LINK FOR AWS CERTIFICATION
KEY POINT: You receive a wallet card describing your Certification and the Certification belongs to you.
WHO NEEDS TO BE CERTIFIED?
Welders who wish to work for a company that requires Certification as part of their minimum requirements for employment (an increasing number of companies now require welders to demonstrate their skills and, or be Certified)
Welders currently working for companies that must show certification to their clients or general contractors need to be certified.
In many cases Welders that have been certified, either at another company or have not welded for a period of time, may need to be recertified. Some welders are required to take periodic tests to determine their continued competency.
Welders who wish to prove their abilities or further their career goals will take a certification or additional certifications.
KEY POINT: Be proud to be a welder prove your one of the best
WHAT DOES MY CERTIFICATION MEAN?
Certification is very specific to a particular Code, Standard or Welding Procedure and any changes in the variables used in welding may require re-certification. Personnel familiar with the governing document usually determines if the certification is valid for the work being performed.
Welders however; should know in general what their certification covers so they don’t mislead clients or run into difficulty on the job. The variables used in qualification and the qualification range of the certification is listed on the following documents;
Welder Qualification Test Report WQTR
The WQTR describes the results of the welding test, including what the welder is qualified to do.
The Welding Procedure specification WPS
The WPS describes the rules, welding parameters and details of the test, or how the pieces should be assembled and welded. The WPS is like a Blueprint or set of written instructions for the test.
Welding Procedure Qualification Report WPQR
The WPQR documents the variables and tests that have been performed by a qualified individual to prove the test is valid. The document and supporting information proves that the joint can be welded and tested to meet the specific Standard or Code requirements. The document if followed removes all variables except the skill of the welder.
This document and its variables are used to construct the WPS.
WHAT A CERTIFICATION IS NOT?
A certification is not a license to weld anything at anytime under any circumstances.
A certification is specific to a certain code and set of variables that allow repetition of demonstrated skills.
A certification is not a guarantee that welders will not make mistakes. It certifies that the tester has witnessed the welder demonstrate a specific skill level and produced a sound (good or acceptable) Weld. The assumption is that the welder has the ability to reproduce results in an actual work environment.
Certification in one Process does not extend to other welding process. For example a welder certified in SMAW (Stick) is not certified to weld with GMAW (mig) The welder may have the skills but he has not demonstrated them in a testing environment and is not Certified.
Certification to one code does not mean certification to all codes.
Certification is specific to variables such as; Base metal, Filler metal, Welding position, vertical direction of travel, joint design, joint configuration and thickness of material.
TYPICAL TESTING PROCEDURES AWS D1.1
Single Vee Groove with backing welded in the vertical up 3G position.
The one inch single Vee groove test with a backing bar is an AWS D1.1 pre-qualified joint. The test qualifies the welder to weld fillets or grooves of unlimited thickness in the process the welder used to weld the joint.
The completed joint is visually inspected and specimens are destructively tested by bend testing.
Under the direction of the Test Supervisor, get two pieces of 1x7x3 that have been beveled on one side and assemble and tack weld them in the arrangement shown:
The position the test is welded in determines the positions the Welder is Qualified to weld Grooves and Fillets. This test is often used to test welds produced with the Shielded Metal Arc Welding (STICK) Process.
The test Supervisor will inspect the assembled joint for conformity to the Code and assist in placing the joint in the position for Welding. The test Supervisor will ensure the proper supplies are being used and periodically inspect the welders progress.
The completed joint will be visually inspected according to the requirements of the Code and the bend test coupons shall be cut from the joint.
PREPARING BEND TEST COUPNS
As the picture shows; under the direction of the test Supervisor, two pieces 1” by 3/8” are cut from the welded test piece. The backing bar and weld face reinforcement are ground flush and the pieces are bent to test the weld.
The Test supervisor evaluates the bent pieces for acceptability and conformance to the requirements of the Code.
The acceptance criteria for bend tests in accordance with the AWS D1.1 are as follows;
· The convex surface of the bend test specimen shall be examined for surface discontinuities exceeding the following dimensions:
· 1/8 inch measured in any direction on the surface.
· 3/8 inches - the sum of the greatest dimensions of all discontinuities exceeding 1/32 inch but less than or equal to 1/8 inch.
· 1/4 inch the maximum corner crack, except when that crack resulted from visible slag inclusion or other fusion type discontinuities, then the 1/8 inch maximum shall apply.
FILLET WELD BREAK TEST ALL POSITION QUALIFICATION
The fillet weld break test is a simpler test that qualifies the welder to weld fillets with the process used during the test. The welding position qualified works like the positions for grooves discussed earlier. To qualify all positions fillet welding, the welder must pass a separate break test in the vertical and the overhead positions.
When the welder is only welding fillet welds as is often the case with the GMAW (MIG) and GTAW (TIG) processes, a fillet weld break test in all positions instead of a groove test may be the only requirement for the job.
To perform the test, the welder weld a T joint on one side with a restart near the center as shown. The piece is visually examined and a macroetch test is conducted on one end piece. The piece is then broken to visually inspect for complete fusion and to ensure there are no discontinuities according to the acceptance criteria of the Code.
The acceptance criteria for fillet weld break tests in accordance with the AWS D1.1 are as follows;
To pass the visual examination prior to the break test, the weld shall present a reasonably uniform appearance and shall be free from overlap, cracks, or excessive undercut as defined by the Code. There shall be no porosity visible on the weld surface.
The broken specimen shall pass if:
· The specimen bends flat upon itself.
· The fillet weld, if fractured, has a fracture surface showing complete fusion to the root of the joint with no inclusion or porosity larger than 3/32 of an inch in greatest dimension.
· The sum of the greatest dimension of all inclusions shall not exceed 3/8” of an inch in the 6 inch long specimen.