Destructive Examination • Destructive Examination renders the weld or material unfit for further service.
Common methods used in Destructive Examination • Bend testing • Tensile testing • Impact testing • Hardness testing • Chemical analysis & Metallography • Hydrostatic testing to destruction
Mechanical Testing Tension
Tensile Strength Testing • “Tensile” is a test in which a prepared sample is pulled until the sample breaks. • Test Measurements are recorded in PSI (Pounds per Square Inch) E7018 = 70,000 PSI Tensile • Test samples called “Tensile Bolts” can reveal a welds Tensile strength, Elastic limit, Yield point, and Ductility.
Tensile Strength Testing • The Elastic Limit of metal is the stress (load) it can withstand and still return to the original length after the load is released. • Yield Strength occurs when the test sample stretches however will not return to its original length. • Ductility is the ability of a metal to stretch or elongate before it breaks.
Bend Testing • Bend test samples are referred to as “Test Coupons” • The most common bend tests are • Guided face and root bend testing • Guided side bend testing • Longitudinal root and side bend testing • Fillet weld bend testing • Unguided bend testing