A test to obtain an accurate assessment of the strength and ductility of a material or a weld, or in an all-weld-metal test, to determine mechanical properties such as tensile strength, yield strength, elongation, and reduction in area.
In a base metal tension test, the strength and ductility of metals are generally obtained from a uniaxial tensile test in which a machined specimen is subjected to an increasing load while simultaneous observations of extension are made. Longitudinal specimens are oriented parallel to the direction of rolling, and transverse specimens are oriented perpendicular to the rolling direction. The load can be plotted against the
elongation, customarily as shown in Figure T-1. The stress (load divided by original area) is plotted against the strain (elongation divided by the original gauge length).
The yield strength shown by the engineering stress-strain curve is generally the strength at some arbitrary amount of extension under load or a permanent plastic strain (offset).
Details of specimen preparation and test procedures for tension tests for base metals are described in ASTM A370, Standard Methods and Definitions for Mechanical Testing of Steel Products, published by the American Society for Testing Materials, West Consho hocken, Pennsylvania.
Weld Tension Test. To obtain an accurate assessment of the strength and ductility of welds, several different specimens and orientations may be used. In some cases, the weld reinforcement is left intact on the test specimen.
All-Weld-Metal Test. The mechanical properties measured and reported in an all-weld-metal tension test are tensile strength, yield strength, elongation, and reduction in area. To determine the tensile properties of a weld metal, the test specimen orientation is parallel to the axis of the weld, and the entire specimen is machined from the weld metal. The chemical composition of the weld metal will be affected by the joint penetration.
If the purpose of the test is to qualify a filler metal, then melting of the base metal should be minimized when making the test weld. This procedure is described in AWS A5.1, Specification for Covered Carbon Steel Arc Welding Electrodes, published by American Welding Society, Miami, Florida.