Welds can be tested by destructive and non-destructive techniques. Most production is tested by use of non-destructive methods. The most common non-destructive tests to check welds are Visual Inspection, Liquid Penetrant, Magnetic Particle, Eddy Current, Ultrasonic, Acoustic Emission and Radiography.
Visual Inspection Of The Weld
The basic method of checking the quality of a weld is to inspect it for any flaws visually. Look for any cracks, beads, bends, craters, excessive reinforcements, or other flaws and inform any concerned authorities about it.
The most common types of nondestructive testing for welds, excluding simple sensory examinations, are liquid penetrant, radiography, magnetic particle, eddy current, and ultrasonic testing.
Most weld inspection techniques can be divided into two categories: non-destructive weld inspection and destructive weld inspection.
The basic conditions of welding quality to achieve products of such high quality includes the following: No cracks or holes found in the bead. The bead has uniform waves, width and height. The finished product satisfies the design dimensions and has almost no distortion.
Signs of a bad weld include: Burnout, no filler metal used, wide flat bead without distinct bead pattern, erratic beads, tungsten inclusion, porosity and/or undercutting.
For technical reasons welded joints require appropriate mechanical properties such as: tensile strength, bending, ductility, toughness, and resistance to aggressive media.
Most tests consist of: Following the instructions and welding the metals in the required position. Cutting the metal welded according to the instructions and preparing it for a bend test or another approved method for quality testing. Performing bend tests and radiographic (x-ray) tests on the material.
Visual inspection is a non-destructive testing (NDT) weld quality testing process where a weld is examined with the eye to determine surface discontinuities. It is the most common method of weld quality testing.
Welded joints are inspected either by conducting destructive or non-destructive tests: a) Destructive tests: Tensile test, Bend test, Hardness test, etc. b) Non-destructive tests: Dye penetrant test, Magnetic particle testing, and Ultrasonic Testing.
The 1G welding certification position is a plate in the flat position that is beveled. This position is the most basic and only covers the welder in that position. It's the easiest test to pass and the least desired by employers.
A Welder Performance Qualification (WPQ) is a test certificate that shows whether a welder possesses the necessary experience and knowledge to perform the specifications of a particular weld procedure.
Tests must be made to qualify the process(es) and the operators. Inspection usually involves the examination of completed welds to establish their quality and their confirmation to specifications. Thus, testing and inspection determines whether or not the quality standards of materials and workmanship are being met.
Pipe welding is considered one of the more difficult processes for welders to master. In order to pass pipe welding tests, you must be able to join two cylindrical metal pipes together utilizing shielded metal arc welding or any number of other methods.
Integrity is by far the most important must-have quality of a welding inspector. The definition of integrity is 'the quality of being honest and having strong moral principles'.
Welding Inspectors examine the connections and bonds between metals. Inspectors use visual tools and electrical instruments to check and ensure the quality and safety of connections. Certified welding inspectors play an intrinsic role in the welding industry.
How long does a weld test take? Turnaround times can vary due to lab test volume, but simple certification tests can often be completed in 2 days. More thorough inspections for certifications can take longer.
If either weld fails, you may retest at any time within a month, but you must deposit two sound welds of that type. You may not test again for six months if you fail the retest, and when you test again you must fabricate two weld tests plates of the type and position you previously failed.
How long is my certification valid? AWS Certification remains valid as long as you submit your Certification Maintenance Form every six months as required by the Code of Acceptance that governs your test.