The tension test related to the mechanical testing of steel products subjects a machined or full-section specimen of the material under examination to a measured load sufficient to cause rupture. Ultimate Tensile Strength, Yield Strength, True Stress and Strain, Engineering Stress and Strain, the Elastic Modulus, the Fracture Stress, the Modulus of Toughness, and the Modulus of Resilience, may all be determined by tensile testing.
CHARPY IMPACT TEST
The Charpy Impact Test is a cost-effective test method used to determine the material’s relative impact toughness at a specific temperature. Specimens are first machined to a specific dimension and surface finish before being notched and placed in a liquid bath until the specimens have reached the test temperature. The specimen is then loaded into the test machine and struck with a weighted pendulum released from a set height within 5 seconds of leaving the liquid bath. The higher the absorbed energy of the specimen, the greater the relative impact toughness of the material. The resulting test data is used when qualifying welding procedures, evaluating heat treatment processes or verifying material type and grade, normally on welds or materials intended for low temperature applications such as ship hulls or marine structures.
GUIDE BEND TEST
The guide bend test is used to verify the ductility of the material. If the material does not fracture after bending, the piece is visually checked for cracking or other surface irregularities. The specimen are place on the die member of the jig with the weld at midspan.
FRACTURE/ NICK-BREAK TEST
The Fracture or Nick Break Test is used to determine the quality of a weld, and involves breaking open the weld length-wise, and then visually inspecting the exposed weld interior for any internal imperfections such as lack of sidewall fusion, lack of inter-run fusion and porosity. The test can be carried out for both Butt Welds and Fillet Welds Test coupons.
A hardness test is a means of determining resistance to penetration and is occasionally employed to obtain a quick approximation of tensile strength. There are 3 types of hardness tests: