ASME SA-370-2019 pdf free download.TEST METHODS AND DEFINITIONS FOR MECHANICAL TESTING OF STEEL PRODUCTS
3. General Precautions
3.1 Certain methods of fabrication, such as bending, forming, andwelding, oroperations involving heating, may affect the properties of the material under test. Therefore, the product specifications coverthe stage ofmanufacture at whichmechanicaltesting is tobeperformed. Theproperties shown by testing prior to fabrication may not necessarily be representative ofthe productafterithas been completely fabricated.
3.2 Improper machining or preparation of test speci- mens may give erroneous results. Care should be exercised to assure good workmanship in machining. Improperly machined specimens should be discarded and other speci- mens substituted.
3.3 Flaws in the specimen may also affect results. If any test specimen develops flaws, the retest provision of the applicable product specification shall govern.
3.4 If any test specimen fails because of mechanical reasons such as failure of testing equipment or improper specimen preparation, it may be discarded and another specimen taken.
4. Orientation of Test Specimens
4.1 The terms “longitudinal test” and “transverse test” are used only in material specifications for wrought prod- ucts andarenotapplicableto castings. Whensuchreference is made to a test coupon or test specimen, the following definitions apply:
4.1.1 Longitudinal Test, unless specifically defined otherwise, signifies thatthelengthwiseaxis ofthespecimen is parallel to the direction of the greatest extension of the steel during rolling or forging. The stress applied to a longitudinal tension test specimen is in the direction of the greatest extension, and the axis ofthe fold ofa longitudinal bend test specimen is at right angles to the direction of greatest extension (Fig. 1, Fig. 2a, and 2b).
4.1.2 Transverse Test, unless specifically defined otherwise, signifies thatthelengthwise axis ofthe specimen is at right angles to the direction of the greatest extension of the steel during rolling or forging. The stress applied to a transverse tension test specimen is at right angles to the greatest extension, and the axis of the fold of a trans- versebendtestspecimenis parallelto thegreatestextension (Fig. 1).
4.2 The terms “radial test” and “tangential test” are used in material specifications for some wrought circular products and are not applicable to castings. When such reference is made to a test coupon or test specimen, the following definitions apply:
4.2.1 Radial Test, unless specifically defined other- wise, signifies that the lengthwise axis of the specimen is perpendicular to the axis of the product and coincident with one of the radii of a circle drawn with a point on the axis of the product as a center (Fig. 2a).
4.2.2 Tangential Test, unless specifically defined otherwise, signifies thatthelengthwiseaxis ofthespecimen is perpendicular to a plane containing the axis of the prod- uct and tangent to a circle drawn with a point on the axis of the product as a center (Fig. 2a, 2b, 2c, and 2d). TENSION TEST
5. Description
5.1 The tension test related to the mechanical testing of steel products subjects a machined or full-section speci- men of the material under examination to a measured load sufficient to cause rupture. The resulting properties sought are defined in Terminology E 6.
5.2 In general, the testing equipment and methods are given in Test Methods E 8. However, there are certain exceptions to Test Methods E 8 practices in the testing of steel, and these are covered in these test methods.
7. Testing Apparatus and Operations
7.1 Loading Systems — There are two general types of loading systems, mechanical (screw power) and hydraulic. These differ chiefly in the variability of the rate of load application. The older screw power machines are limited to a small number of fixed free running crosshead speeds. Some modern screw power machines, and all hydraulic machines permit stepless variation throughout the range of speeds.
7.2 The tension testing machine shall be maintained in good operating condition, used only in the proper loading range, and calibrated periodically in accordance with the latest revision of Practices E 4.
NOTE 1 — Many machines are equipped with stress-strain recorders for autographic plotting of stress-strain curves. It should be noted that some recorders have a load measuring component entirely separate from the load indicator of the testing machine. Such recorders are calibrated separately.
7.3 Loading — It is the function of the gripping or holding device of the testing machine to transmit the load from the heads of the machine to the specimen under test. The essential requirement is that the load shall be transmitted axially. This implies that the centers of the action ofthe grips shall be in alignment, insofaras practica- ble, with the axis of the specimen at the beginning and during the test and that bending or twisting be held to a minimum. For specimens with a reduced section, gripping of the specimen shall be restricted to the grip section. In the case of certain sections tested in full size, nonaxial loading is unavoidable and in such cases shall be permis- sible.ASME SA-370 pdf download.ASME SA-370-2019 pdf free download
